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SupplementAbsorption.comPreview · grades pending reviewer sign-off

Creatine Absorption: HCl vs Monohydrate

Evidence reviewed by Dr. Colin Reily, PhD · Draft, pending reviewer sign-off · Data built 2026-10-31

Bottom line

Grade BB: solid human data. Forms: 3+ human studies. Comparisons: one randomized head-to-head, or matched single-form evidence from 2+ studies per form. All grades are drafts pending reviewer sign-off.Draft — pending reviewer review

We found 24 studies with usable absorption data for this supplement, 12 of them in people; every value below is copied from its paper and cited.

Monohydrate is the best-characterized form: 3 human studies (total n=17) with measured absorption values (absorption evidence grade B, draft).

No human head-to-head comparison of the popular forms has turned up yet, so we don't rank them; the measured values for each form are below.

Studies in database
68 (+24 full-text)
Species
35 human, 15 rodent, 15 other animal, 3 species unclear

Educational information about published research; not medical advice. Not intended to diagnose, treat, cure or prevent any disease. Talk to a clinician before changing supplements, especially if pregnant, nursing or on medication.

On this page

33 of 68 studies are not in humans; each is labeled with a species badge.

Creatine forms compared

Creatine forms and studies
FormStudies (abstract screen)Species
Monohydrate[PMID 41809290][PMID 42654277][PMID 40182172][PMID 35619864][PMID 28121472][PMID 20698808][PMID 19228401][PMID 19437189][PMID 19211722][PMID 17997838][PMID 16416332][PMID 15513279][PMID 12520625][PMID 12015375][PMID 11745717][PMID 11509496][PMID 10694120][PMID 34836240][PMID 34171201][PMID 29518030][PMID 26639507][PMID 12151051][PMID 35277060]HumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanRodentRodentRodentRodentRodentOther animal
HClnone yet
Ethyl ester[PMID 19228401][PMID 19585404]HumanHuman

Form tags are matched automatically and need reviewer confirmation. Values are not normalized across studies.

Species (abstract screen): 18 human, 5 rodent, 1 other animal
Show 24 studies with verbatim quotes
  • HumanComparative Efficacy and Pharmacokinetic Parameters of Micronized Creatine Monohydrate (KleanCREATINE™) in Active Men: A Randomized, Controlled Clinical Study.
    Cureus, 2026 · n 10 healthy men · [PMID 41809290]
    • Key findings · abstract:Results In Phase I, KleanCREATINE™ demonstrated better pharmacokinetics profile with higher Cmax (8.10 vs 4.80 nmol/UI), quicker Tmax (2 vs 3 hours), and greater relative bioavailability (160.42% in sequence one and 175.45% in sequence two) over the marketed formulation.
    • Key findings · abstract:KleanCREATINE™ showed greater chest press endurance (60.05% vs 49.29%).
    • Cmax · abstract:Results In Phase I, KleanCREATINE™ demonstrated better pharmacokinetics profile with higher Cmax (8.10 vs 4.80 nmol/UI), quicker Tmax (2 vs 3 hours), and greater relative bioavailability (160.42% in sequence one and 175.45% in sequence two) over the marketed formulation.
    • +2 more quotes in Studies
  • HumanMethodological Approaches to Bioavailability of Oral Creatine in Randomized Controlled Trials: A Meta-Research Study.
    Nutrients, 2026 · [PMID 42654277]
    • Key findings · abstract:Bioavailability was mentioned in only 38 (11.1%) reports, most frequently in the discussion section.
    • Key findings · abstract:Four trials (1.2%) reported specific measures intended to enhance bioavailability, including instructions regarding supplement dissolution or co-ingestion with food or carbohydrates.
    • Key findings · abstract:Five trials (1.5%) compared more than one creatine formulation, but only three (0.9%) discussed bioavailability.
    • +2 more quotes in Studies
  • HumanEnhanced Absorption and Safety of MuscleBlaze CreAMP™: A Comparative Analysis With Regular Micronized Creatine Monohydrate in Healthy Male Adults.
    Cureus, 2025 · [PMID 40182172]
    • Key findings · abstract:This study evaluated the bioavailability and safety of MuscleBlaze Creatine Monohydrate (CreAMP™) (Bright Lifecare Pvt Ltd, Gurugram, India), containing 3.0 g creatine monohydrate and 0.1 g Creabsorb™ (Indian Patent: IN202311057466), against a standard 3.0 g micronized creatine dose.
    • Key findings · abstract:With a 38.97% increase in bioavailability, an 18.10% higher Cmax, a 21.37% longer half-life, 34.67% lower clearance, and a 10.13% higher mean residence time, CreAMP™ demonstrates superior pharmacokinetic properties.
    • Cmax · abstract:With a 38.97% increase in bioavailability, an 18.10% higher Cmax, a 21.37% longer half-life, 34.67% lower clearance, and a 10.13% higher mean residence time, CreAMP™ demonstrates superior pharmacokinetic properties.
    • +1 more quotes in Studies
  • HumanPharmacokinetic Evaluation of a Single 5-Gram Bolus of Creatine Monohydrate Versus Two Other Creatine-Containing Investigational Products.
    Cureus, 2022 · [PMID 35619864]
    • Key findings · abstract:Cmax data indicate that CreaBev 1 10.55±4.10, CreaBev 2 15.45±5.48, and creatine monohydrate 12.77±4.0 nmol/h/μL.
    • Key findings · abstract:The AUC data indicate that CreaBev 1 22.90±9.17, CreaBev 2 33.92±9.52, and creatine monohydrate 29.58±11.93 nmol/h/μL.
    • Key findings · abstract:When examining the data for pharmacokinetics, the AUC and Cmax pharmacokinetics were greatest for CreaBev 2 (p<0.021 and 0.020).
    • +5 more quotes in Studies
  • HumanPlasma Creatine Kinetics After Ingestion of Microencapsulated Creatine Monohydrate with Enhanced Stability in Aqueous Solutions.
    J Diet Suppl, 2017 · n n = 5 · [PMID 28121472]
    • Key findings · abstract:Three hours after ingestion, plasma creatine concentrations were unchanged during PLA, and averaged ∼45 μM.
    • Key findings · abstract:During CRE, plasma creatine concentration peaked after 30 min at 101.6 ± 14.9 μM (p < 0.05), representing a 2.3-fold increase over PLA.
    • Key findings · abstract:Thereafter, plasma creatine concentration gradually trended downwards but remained significantly elevated (∼50% above resting levels) 3 hr after ingestion.
    • +1 more quotes in Studies
  • HumanA phase I, pharmacokinetic, dosage escalation study of creatine monohydrate in subjects with amyotrophic lateral sclerosis.
    Amyotroph Lateral Scler, 2010 · [PMID 20698808]
    • Key findings · abstract:The objectives of this study were to establish steady-state plasma pharmacokinetics of creatine at several dosages, and to evaluate the effects of creatine on brain metabolites using proton magnetic resonance spectroscopy ((1)H-MRS).
    • Key findings · abstract:Mean pre-dose steady-state creatine plasma concentrations were 20.3, 39.3, and 61.5 ug/ml at 5, 10, and 15 g b.i.d., respectively.
    • Key findings · abstract:Creatine spectra increased by 8% (p = 0.06) and glutamate + glutamine signals decreased by 17% (p = 0.039) at higher dosages.
  • HumanThe effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels.
    J Int Soc Sports Nutr, 2009 · [PMID 19228401]
    • Key findings · abstract:This study examined how a seven-week supplementation regimen combined with resistance training affected body composition, muscle mass, muscle strength and power, serum and muscle creatine levels, and serum creatinine levels in 30 non-resistance-trained males.
    • Key findings · abstract:Results showed significantly higher serum creatine concentrations in PLA (p = 0.007) and CRT (p = 0.005) compared to CEE.
    • Key findings · abstract:Serum creatinine was greater in CEE compared to the PLA (p = 0.001) and CRT (p = 0.001) and increased at days 6, 27, and 48.
    • +2 more quotes in Studies
  • HumanQualitative in vitro NMR analysis of creatine ethyl ester pronutrient in human plasma.
    Int J Sports Med, 2009 · [PMID 19585404]
    • Key findings · abstract:Lyophilized human plasma was reconstituted in D2O and phosphate-buffered saline and 1.5 mg of the analyte was added.
  • HumanUrinary creatine and methylamine excretion following 4 x 5 g x day(-1) or 20 x 1 g x day(-1) of creatine monohydrate for 5 days.
    J Sports Sci, 2009 · n n = 6 · [PMID 19437189]
    • Key findings · abstract:In this study, we examined the effect of two creatine monohydrate supplementation regimes on 24-h urinary creatine and methylamine excretion.
    • Key findings · abstract:Less creatine was excreted following the 20 x 1 g x day(-1) regime (49.25 +/- 10.53 g) than the 4 x 5 g x day(-1) regime (62.32 +/- 9.36 g) (mean +/- s;[excerpt truncated in our database — see source]
    • Key findings · abstract:Mean total excretion of methylamine (n = 6) over days 3-7 was 8.61 +/- 7.58 mg and 24.81 +/- 25.76 mg on the 20 x 1 g x day(-1) and 4 x 5 g x day(-1) regimes, respectively (P < 0.05).
    • +1 more quotes in Studies
  • HumanInfluence of dietary creatine supplementation on muscle phosphocreatine kinetics during knee-extensor exercise in humans.
    Am J Physiol Regul Integr Comp Physiol, 2009 · [PMID 19211722]
    • HumanComparison of new forms of creatine in raising plasma creatine levels.
      J Int Soc Sports Nutr, 2007 · [PMID 17997838]
      • Key findings · abstract:RESULTS: Mean peak concentrations and area under the curve (AUC) were significantly higher with CrPyr (17 and 14%, respectively) in comparison to CrM and CrC.
      • Key findings · abstract:Differences in bioavailability are thought to be unlikely since absorption of CrM is already close to 100%.
      • AUC · abstract:RESULTS: Mean peak concentrations and area under the curve (AUC) were significantly higher with CrPyr (17 and 14%, respectively) in comparison to CrM and CrC.
      • +3 more quotes in Studies
    • HumanEffect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisol.
      Psychopharmacology (Berl), 2006 · n n=10 · [PMID 16416332]
      • Key findings · abstract:They were tested for plasma concentrations of catecholamines and cortisol at 0 and 24 h.
      • Key findings · abstract:Norepinephrine and dopamine concentrations were significantly higher at 24 h than 0 h, but cortisol were lower.
    • HumanThe creatine content of Creatine Serum and the change in the plasma concentration with ingestion of a single dose.
      J Sports Sci, 2004 · [PMID 15513279]
      • Key findings · abstract:(B) 2.5 g creatine monohydrate (Cr.H2O) in solution; and (C) 5 ml Creatine Serum (reportedly containing an equivalent amount of Cr.H2O).
      • Key findings · abstract:Blood samples were collected before and up to 8 h after each treatment and plasma was analysed for creatine and creatinine.
      • Key findings · abstract:Ingestion of 2.5 g creatine monohydrate in solution resulted in a significant increase in plasma creatine (from 59.1+/-11.8 micromol.l(-1) to 245.3+/-74.6 microM micromol.l(-1); mean+/-s) and urinary creatine excretion.
      • +1 more quotes in Studies
    • HumanSingle- and multiple-dose pharmacokinetics of oral creatine.
      J Clin Pharmacol, 2003 · [PMID 12520625]
      • Key findings · abstract:After the single oral dose, the clearance (CL/F) was 0.20 +/- 0.066 L h-1 kg-1, tmax was 1.9 +/- 0.88 hours, and Cmax = 102.1 +/- 11.2 mg h L-1.
      • Key findings · abstract:At steady-state, CL/F decreased to 0.12 +/- 0.016 L h-1 kg-1, tmax did not change, and Cmax increased to 162.2 +/- 30.0 mg L-1.
      • Key findings · abstract:Penetration (AUCMUSCLE/AUCPLASMA) of Cr into the interstitial muscle space, as determined by microdialysis, was 0.47 +/- 0.09 and 0.37 +/- 0.27 for the single dose and at steady-state, respectively.
      • +5 more quotes in Studies
    • HumanEffect of creatine supplementation on oxygen uptake kinetics during submaximal cycle exercise.
      J Appl Physiol (1985), 2002 · n 7 men · [PMID 12015375]
      • Key findings · abstract:The purpose of this study was to test the effect of oral creatine (Cr) supplementation on pulmonary oxygen uptake (VO(2)) kinetics during moderate [below ventilatory threshold (VT)] and heavy (above VT) submaximal cycle exercise.
    • HumanEvaluation of creatine transport using Caco-2 monolayers as an in vitro model for intestinal absorption.
      J Pharm Sci, 2001 · [PMID 11745717]
      • Key findings · abstract:In the present study, creatine transport was examined using Caco-2 monolayers as an in vitro model for intestinal absorption.
    • HumanEffects of acute creatine monohydrate supplementation on leucine kinetics and mixed-muscle protein synthesis.
      J Appl Physiol (1985), 2001 · n n = 13 · [PMID 11509496]
      • Key findings · abstract:A primed-continuous intravenous infusion of L-[1-(13)C]leucine and mass spectrometry were used to measure mixed-muscle protein fractional synthetic rate and indexes of whole body leucine metabolism (nonoxidative leucine disposal), leucine oxidation, and plasma leucine rate of appearance.
      • Key findings · abstract:CrM supplementation did not increase muscle fractional synthetic rate but reduced leucine oxidation (-19.6%) and plasma leucine rate of appearance (-7.5%, P < 0.05) in men, but not in women.
    • HumanCreatine enhances oxygen uptake and performance during alternating intensity exercise.
      Med Sci Sports Exerc, 2000 · [PMID 10694120]
      • Key findings · abstract:Oxygen uptake was measured using a breath-by-breath system during bicycle exercise alternating every 3 min between bouts at 30%(-30%) and 90% (-90%) of the maximal power output to exhaustion.
      • Key findings · abstract:Blood ammonia accumulation at the end of 1-90% (23.1 +/- 6.5 micromol x L(-1)) and 3-30% (64.7 +/- 15.2 micromol x L(-1)) was lower after CR (P < 0.05), whereas plasma uric acid accumulation was lower at exhaustion (P < 0.05) and 5-min postexercise (P < 0.01).
    • RodentEffects of Low Doses of L-Carnitine Tartrate and Lipid Multi-Particulate Formulated Creatine Monohydrate on Muscle Protein Synthesis in Myoblasts and Bioavailability in Humans and Rodents.
      Nutrients, 2021 · [PMID 34836240]
      • Key findings · abstract:When Wistar rats were administered creatine with LMP formulation at either 21 or 51 mg/kg, bioavailability was increased by 27% based on the increase in the area under the curve (AUC) at a 51 mg/kg dose compared to without LMP formulation.
      • Key findings · abstract:Finally, in human subjects, a combination of LMP formulated L-carnitine at 500 mg (from L-carnitine tartrate) with LMP formulated creatine at 100, 200, or 500 mg revealed a significant and dose-dependent increase in plasma creatine concentrations.
      • AUC · abstract:When Wistar rats were administered creatine with LMP formulation at either 21 or 51 mg/kg, bioavailability was increased by 27% based on the increase in the area under the curve (AUC) at a 51 mg/kg dose compared to without LMP formulation.
    • RodentSex- and tissue-dependent creatine uptake in response to different creatine monohydrate doses in male and female Sprague-Dawley rats.
      Appl Physiol Nutr Metab, 2021 · n n = 32 · [PMID 34171201]
      • Key findings · abstract:Total creatine (TCr) concentrations in female white fibre-dominant gastrocnemius (WGAS) and cardiac muscle (HRT) were significantly higher compared with males (p < 0.05).
    • RodentAbsolute Oral Bioavailability of Creatine Monohydrate in Rats: Debunking a Myth.
      Pharmaceutics, 2018 · [PMID 29518030]
      • Key findings · abstract:Plasma and tissue levels of 13C-labeled creatine were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS).
      • Key findings · abstract:Absolute oral bioavailability for low dose CM was 53% while high dose CM was only 16%.
      • Key findings · abstract:The simulated Cmax of 70 mg/kg CHCL was around 35 μg/mL compared to 14 μg/mL for CM with a predicted oral bioavailability of 66% with CHCL compared to 17% with CM.
      • +1 more quotes in Studies
    • RodentEffect of creatine monohydrate supplementation on relative serum level of IL-6 and IL-18 following neonatal hypoxia ischemia in male albino mouse.
      Pak J Pharm Sci, 2015 · [PMID 26639507]
      • Key findings · abstract:In the present study, we tried to determine whether 2% Creatine monohydrate supplementation for variable duration influence the IL-6 and 18 concentrations in the serum of male albino mouse following right common carotid artery ligation and hypoxia (8% oxygen) for 25 minutes.
      • Key findings · abstract:Our result revealed that serum concentration of IL6 (P=0.0001) as well as IL-18 (P=0.003) were significantly higher in mice supplemented with creatine monohydrate for 15 weeks than in male albino mice on normal rodent diet following hypoxic ischemic insult indicating that long term creatine monohydrate supplementation up[excerpt truncated in our database — see source]
    • RodentThe effect of creatine supplementation on glucose uptake in rat skeletal muscle.
      Life Sci, 2002 · [PMID 12151051]
      • Key findings · abstract:(3)H-2-deoxyglucose uptake was measured in epitrochlearis muscles incubated in the presence or absence of a maximally stimulating dose of insulin.
    • Other animalThe Dietary Supplement Creatyl-l-Leucine Does Not Bioaccumulate in Muscle, Brain or Plasma and Is Not a Significant Bioavailable Source of Creatine.
      Nutrients, 2022 · [PMID 35277060]

      Creatine hcl vs monohydrate: which absorbs better?

      No study in our database compares these two forms directly.

      Species (abstract screen): no studies
      No relevant studies in our database address this question yet. We don't fill gaps with guesses.

      Measured absorption data (full-text extraction)

      41 papers read in full text, 24 with usable data (17 excluded as off-topic, reviews or off-target). 95 values extracted. Species: Human 12Rodent 6In vitro 5Other animal 1

      Grades: draft — pending reviewer (Dr. Colin Reily). Directions are auto-parsed from author statements; values are copied exactly as printed, never converted or estimated.

      Forms with measured values

      FormStudiesValuesAbsorption evidence gradeSpecies
      Monohydrate534Grade BB: solid human data. Forms: 3+ human studies. Comparisons: one randomized head-to-head, or matched single-form evidence from 2+ studies per form. All grades are drafts pending reviewer sign-off.
      3 human studies, total n=17, 2 randomized/crossover; consistency not evaluable (no matched set with ≥2 studies)
      		Human×3Rodent×1Other animal×1
      HClnone yet0Not gradedNot graded: no comparable evidence yet. All grades are drafts pending reviewer sign-off.
      no single-form human values
      Ethyl esternone yet0Not gradedNot graded: no comparable evidence yet. All grades are drafts pending reviewer sign-off.
      no single-form human values

      Single-form studies count as evidence for that form. Form tags are keyword-matched from arm descriptions and need reviewer confirmation.

      Head-to-head comparisons

      Not gradedNot graded: no comparable evidence yet. All grades are drafts pending reviewer sign-off.HCl vs Monohydratecombined head-to-head + matched single-form grade

      no comparable evidence. H2H: none (no direct comparison in extracted data); indirect: none

      Cmax, Tmax and AUC by study arm (93 values)
      StudyArm / formDoseFednAnalyteParamValueUnitsSource
      Human 11811571Study 1 session C: creatine solution
      Cr·H2O powder dissolved in 250 ml 30°C water
      		2.3 g Cr·H2O (equivalent to 2 g creatine) (salt/compound)fasted5creatine (plasma)Cmax
      Peak plasma creatine
      		287 ± 115 (SD)µmol·l-1Results Study 1 p.149 (page image)
      Human 11811571Study 1 session B: creatine in meat (rump steak)
      lightly fried rump steak 395-426 g (average 408 g)
      		2.20 ± 0.08 g creatine (equivalent to 2.50 g Cr·H2O) (active compound)fasted overnight; steak meal5creatine (plasma)Cmax
      Peak plasma creatine after meat
      		182 ± 52.4 (SD)µmol·l-1Results Study 1 p.149 (page image)
      Human 11811571Study 1 session B: creatine in meat (rump steak)
      lightly fried rump steak 395-426 g (average 408 g)
      		2.20 ± 0.08 g creatine (equivalent to 2.50 g Cr·H2O) (active compound)fasted overnight; steak meal5creatine (plasma)Tmax
      Time of peak after meat (individual counts)
      		two participants at 1 h, two at 1.5 h and two at 2 h hResults Study 1 p.149
      Human 11811571Study 1 session C: creatine solution
      Cr·H2O powder dissolved in 250 ml 30°C water
      		2.3 g Cr·H2O (equivalent to 2 g creatine) (salt/compound)fasted5creatine (plasma)AUC
      Area under plasma creatine curve (trapezoidal; assumes linear decline to pre-dose at 8 h)
      		507 ± 205 (SD)µmol·h·l-1Results Study 1 p.149 (page image)
      Human 11811571Study 1 session B: creatine in meat (rump steak)
      lightly fried rump steak 395-426 g (average 408 g)
      		2.20 ± 0.08 g creatine (equivalent to 2.50 g Cr·H2O) (active compound)fasted overnight; steak meal5creatine (plasma)AUC
      Area under plasma creatine curve (trapezoidal; assumes linear decline to pre-dose at 8 h)
      		518 ± 153 (SD)µmol·h·l-1Results Study 1 p.149 (page image)
      Human 11811571Study 2 session D: creatine solution
      Cr·H2O dissolved in 250 ml 30°C water
      		2.3 g Cr·H2O (2 g creatine) (salt/compound)fasted5creatine (plasma)Cmax
      Mean peak plasma creatine (solution)
      		386 ± 87.7 (SD)µmol·l-1Results Study 2 p.149 (page image)
      Human 11811571Study 2 session D: creatine solution
      Cr·H2O dissolved in 250 ml 30°C water
      		2.3 g Cr·H2O (2 g creatine) (salt/compound)fasted5creatine (plasma)AUC
      Area under plasma creatine curve (solution)
      		622 ± 193 (SD)µmol·h·l-1Results Study 2 p.149 (page image)
      Human 11811571Study 2 session F: compressed lozenges (crushed and swallowed)
      two compressed flavoured lozenges, each 1.1-1.2 g Cr·H2O, followed by 300 ml water
      		2.3 g Cr·H2O (two lozenges of 1.1-1.2 g) (salt/compound)fasted5creatine (plasma)Cmax
      Mean peak plasma creatine (lozenge)
      		277 ± 52.7 (SD)µmol·l-1Results Study 2 p.149 (page image)
      Human 11811571Study 2 session E: crystalline suspension in ice-cold water
      Cr·H2O suspension in 250 ml ice-cold water
      		2.3 g Cr·H2O (salt/compound)fasted5creatine (plasma)Cmax
      Mean peak plasma creatine (suspension)
      		269 ± 66.6 (SD)µmol·l-1Results Study 2 p.149 (page image)
      Human 11811571Study 2 session F: compressed lozenges (crushed and swallowed)
      two compressed flavoured lozenges, each 1.1-1.2 g Cr·H2O, followed by 300 ml water
      		2.3 g Cr·H2O (two lozenges of 1.1-1.2 g) (salt/compound)fasted5creatine (plasma)AUC
      Area under plasma creatine curve (lozenge)
      		438 ± 131 (SD)µmol·h·l-1Results Study 2 p.149 (page image)
      Human 11811571Study 2 session E: crystalline suspension in ice-cold water
      Cr·H2O suspension in 250 ml ice-cold water
      		2.3 g Cr·H2O (salt/compound)fasted5creatine (plasma)AUC
      Area under plasma creatine curve (suspension)
      		399 ± 196 (SD)µmol·h·l-1Results Study 2 p.149 (page image)
      Human 12520625Single dose (Day 1)
      Creatine monohydrate powder dissolved in 250 mL water (+50 mL rinse)
      		71 mg/kg BW (62 mg creatine/kg) (salt/compound)fasted (breakfast ≥3 h prior)6creatine (total plasma) (plasma)Cmax102.1 ± 11.2 (SD)mg L–1Table II
      quote mismatch, check
      Human 12520625Steady state (Day 8)
      Creatine monohydrate powder
      		71 mg/kg BW (salt/compound)fasted at dosing on Day 86creatine (total plasma) (plasma)Cmax162.2 ± 30.0 (SD)mg L–1Table II
      quote mismatch, check
      Human 12520625Single dose (Day 1)
      Creatine monohydrate powder dissolved in 250 mL water (+50 mL rinse)
      		71 mg/kg BW (62 mg creatine/kg) (salt/compound)fasted (breakfast ≥3 h prior)6creatine (unbound interstitial) (interstitial muscle fluid (vastus lateralis, microdialysis))Cmax47.9 ± 16.2 (SD)mg L–1Table II
      quote mismatch, check
      Human 12520625Steady state (Day 8)
      Creatine monohydrate powder
      		71 mg/kg BW (salt/compound)fasted at dosing on Day 86creatine (unbound interstitial) (interstitial muscle fluid (vastus lateralis, microdialysis))Cmax52.3 ± 30.3 (SD)mg L–1Table II
      quote mismatch, check
      Human 12520625Single dose (Day 1)
      Creatine monohydrate powder dissolved in 250 mL water (+50 mL rinse)
      		71 mg/kg BW (62 mg creatine/kg) (salt/compound)fasted (breakfast ≥3 h prior)6creatine (total plasma) (plasma)Tmax1.9 ± 0.88 (SD)hTable II
      quote mismatch, check
      Human 12520625Steady state (Day 8)
      Creatine monohydrate powder
      		71 mg/kg BW (salt/compound)fasted at dosing on Day 86creatine (total plasma) (plasma)Tmax1.9 ± 0.58 (SD)hTable II
      quote mismatch, check
      Human 12520625Single dose (Day 1)
      Creatine monohydrate powder dissolved in 250 mL water (+50 mL rinse)
      		71 mg/kg BW (62 mg creatine/kg) (salt/compound)fasted (breakfast ≥3 h prior)6creatine (unbound interstitial) (interstitial muscle fluid (vastus lateralis, microdialysis))Tmax2.1 ± 0.76 (SD)hTable II
      quote mismatch, check
      Human 12520625Steady state (Day 8)
      Creatine monohydrate powder
      		71 mg/kg BW (salt/compound)fasted at dosing on Day 86creatine (unbound interstitial) (interstitial muscle fluid (vastus lateralis, microdialysis))Tmax1.92 ± 0.29 (SD)hTable II
      quote mismatch, check
      Human 12520625Single dose (Day 1)
      Creatine monohydrate powder dissolved in 250 mL water (+50 mL rinse)
      		71 mg/kg BW (62 mg creatine/kg) (salt/compound)fasted (breakfast ≥3 h prior)6creatine (total plasma) (plasma)AUC
      AUC0-∞ (Day 1); AUCss over one dosing interval (Day 8)
      		392 ± 97.8 (SD)mg h L–1Table II
      quote mismatch, check
      Human 12520625Steady state (Day 8)
      Creatine monohydrate powder
      		71 mg/kg BW (salt/compound)fasted at dosing on Day 86creatine (total plasma) (plasma)AUC
      AUC0-∞ (Day 1); AUCss over one dosing interval (Day 8)
      		585 ± 77.7 (SD)mg h L–1Table II
      quote mismatch, check
      Human 12520625Single dose (Day 1)
      Creatine monohydrate powder dissolved in 250 mL water (+50 mL rinse)
      		71 mg/kg BW (62 mg creatine/kg) (salt/compound)fasted (breakfast ≥3 h prior)6creatine (unbound interstitial) (interstitial muscle fluid (vastus lateralis, microdialysis))AUC
      AUC0-∞ (Day 1); AUCss over one dosing interval (Day 8)
      		162 ± 64.3 (SD)mg h L–1Table II
      quote mismatch, check
      Human 12520625Steady state (Day 8)
      Creatine monohydrate powder
      		71 mg/kg BW (salt/compound)fasted at dosing on Day 86creatine (unbound interstitial) (interstitial muscle fluid (vastus lateralis, microdialysis))AUC
      AUC0-∞ (Day 1); AUCss over one dosing interval (Day 8)
      		197 ± 125.3 (SD)mg h L–1Table II
      quote mismatch, check
      Human 15513279Creatine monohydrate solution
      2500 mg Cr·H2O dissolved in 150 ml warm water
      		2500 mg Cr·H2O (salt/compound)after light breakfast following overnight fast6creatine (plasma)Cmax
      Peak plasma creatine (end of mean increase)
      		245.3 ± 74.6 (SD)µmol·l-1Results p.854 (page image); Abstract
      Human 15513279Creatine monohydrate solution
      2500 mg Cr·H2O dissolved in 150 ml warm water
      		2500 mg Cr·H2O (salt/compound)after light breakfast following overnight fast6creatine (plasma)Tmax
      Time of peak plasma creatine
      		between 0.5 and 1 h hResults p.854
      Human 20035494Creatine alone
      creatine + water (~0 kcal)
      		5 g (salt/compound)naso-gastric bolus in 340 ml7plasma creatine (plasma)Cmax
      peak plasma creatine after first bolus (at 30 min)
      		about 800 µmol·l-1Results p.71 'Plasma creatine concentration' para 1
      Human 20035494Creatine alone
      creatine + water (~0 kcal)
      		5 g (salt/compound)naso-gastric bolus in 340 ml7plasma creatine (plasma)Tmax
      time of peak plasma creatine, first bolus
      		30 minResults p.71
      Human 20035494Creatine + carbohydrate
      5 g creatine + ~95 g dextrose (~380 kcal)
      		5 g (salt/compound)naso-gastric bolus in 340 ml with ~95 g dextrose7plasma creatine (plasma)Cmax
      peak plasma creatine (first bolus, per context)
      		743 ± 99 (SEM)µmol·l-1Results p.71 col 2 para 1 (page image)
      Human 20035494Creatine + carbohydrate
      5 g creatine + ~95 g dextrose (~380 kcal)
      		5 g (salt/compound)naso-gastric bolus in 340 ml with ~95 g dextrose7plasma creatine (plasma)Tmax
      time of peak plasma creatine (first bolus, per context)
      		140 minResults p.71 col 2 para 1
      Human 20035494Creatine + protein, amino acids and carbohydrate
      5 g creatine + 14 g whey protein hydrolysate, 7 g leucine, 7 g phenylalanine, 57 g dextrose (~284 kcal)
      		5 g (salt/compound)naso-gastric bolus in 340 ml7plasma creatine (plasma)Cmax
      peak plasma creatine (first bolus, per context)
      		663 ± 101 (SEM)µmol·l-1Results p.71 col 2 para 1 (page image)
      Human 20035494Creatine + protein, amino acids and carbohydrate
      5 g creatine + 14 g whey protein hydrolysate, 7 g leucine, 7 g phenylalanine, 57 g dextrose (~284 kcal)
      		5 g (salt/compound)naso-gastric bolus in 340 ml7plasma creatine (plasma)Tmax
      time of peak plasma creatine (first bolus, per context)
      		100 minResults p.71 col 2 para 1
      Human 20035494Creatine alone
      creatine + water (~0 kcal)
      		5 g (salt/compound)naso-gastric bolus in 340 ml7plasma creatine (plasma)Cmax
      peak plasma creatine after third bolus
      		884 ± 167 (SEM)µmol·l-1Results p.71 col 2 para 2 (page image)
      Human 20035494Creatine alone
      creatine + water (~0 kcal)
      		5 g (salt/compound)naso-gastric bolus in 340 ml7plasma creatine (plasma)Tmax
      time of peak plasma creatine, third bolus
      		45 minResults p.71 col 2 para 2
      Human 20035494Creatine + carbohydrate
      5 g creatine + ~95 g dextrose (~380 kcal)
      		5 g (salt/compound)naso-gastric bolus in 340 ml with ~95 g dextrose7serum insulin (serum)Cmax
      peak serum insulin after first bolus (30 min)
      		46.0 ± 7.7 (SEM)mU·l-1Results p.70
      Human 20035494Creatine + carbohydrate
      5 g creatine + ~95 g dextrose (~380 kcal)
      		5 g (salt/compound)naso-gastric bolus in 340 ml with ~95 g dextrose7serum insulin (serum)Cmax
      peak serum insulin after third bolus (30 min)
      		73.4 ± 17.7 (SEM)mU·l-1Results p.70
      Human 20035494Creatine + protein, amino acids and carbohydrate
      5 g creatine + 14 g whey protein hydrolysate, 7 g leucine, 7 g phenylalanine, 57 g dextrose (~284 kcal)
      		5 g (salt/compound)naso-gastric bolus in 340 ml7serum insulin (serum)Cmax
      peak serum insulin after first bolus (15 min)
      		91.2 ± 27.9 (SEM)mU·l-1Results p.70
      Human 20035494Creatine + protein, amino acids and carbohydrate
      5 g creatine + 14 g whey protein hydrolysate, 7 g leucine, 7 g phenylalanine, 57 g dextrose (~284 kcal)
      		5 g (salt/compound)naso-gastric bolus in 340 ml7serum insulin (serum)Cmax
      peak serum insulin after third bolus (30 min)
      		94.8 ± 17.6 (SEM)mU·l-1Results p.70 (page image)
      Human 28121472Microencapsulated creatine
      Microencapsulated creatine monohydrate in hydrolyzed milk protein, 70-mL ready-to-drink shot
      		3 g (salt/compound)fasted5creatine (plasma)Cmax
      peak plasma creatine
      		101.6 ± 14.9 (SEM)μMAbstract; Results p.441
      Human 28121472Microencapsulated creatine
      Microencapsulated creatine monohydrate in hydrolyzed milk protein, 70-mL ready-to-drink shot
      		3 g (salt/compound)fasted5creatine (plasma)Tmax
      time of peak plasma creatine
      		30 minResults p.441
      Human 31013362IV creatine phosphate disodium
      Creatine phosphate disodium in 50 mL 0.9% saline, IV infusion over 30 min
      		2 g (salt/compound)NR6phosphocreatine (PCr) (plasma)Tmax0.49 ± 0.023 (SD)hTable 8
      Human 31013362IV creatine phosphate disodium
      Creatine phosphate disodium in 50 mL 0.9% saline, IV infusion over 30 min
      		2 g (salt/compound)NR6creatine (Cr, metabolite of PCr) (plasma)Tmax0.55 ± 0.049 (SD)hTable 8
      Human 31013362IV creatine phosphate disodium
      Creatine phosphate disodium in 50 mL 0.9% saline, IV infusion over 30 min
      		2 g (salt/compound)NR6phosphocreatine (PCr) (plasma)Cmax47.34 ± 15.50 (SD)μg/mLTable 8
      Human 31013362IV creatine phosphate disodium
      Creatine phosphate disodium in 50 mL 0.9% saline, IV infusion over 30 min
      		2 g (salt/compound)NR6creatine (Cr, metabolite of PCr) (plasma)Cmax59.29 ± 14.766 (SD)μg/mLTable 8
      Human 31013362IV creatine phosphate disodium
      Creatine phosphate disodium in 50 mL 0.9% saline, IV infusion over 30 min
      		2 g (salt/compound)NR6phosphocreatine (PCr) (plasma)AUC
      AUClast
      		17.07 ± 5.864 (SD)h μg/mLTable 8
      Human 31013362IV creatine phosphate disodium
      Creatine phosphate disodium in 50 mL 0.9% saline, IV infusion over 30 min
      		2 g (salt/compound)NR6creatine (Cr, metabolite of PCr) (plasma)AUC
      AUClast
      		59.63 ± 14.811 (SD)h μg/mLTable 8
      Human 31013362IV creatine phosphate disodium
      Creatine phosphate disodium in 50 mL 0.9% saline, IV infusion over 30 min
      		2 g (salt/compound)NR6phosphocreatine (PCr) (plasma)AUC
      AUCinf
      		17.16 ± 5.885 (SD)h μg/mLTable 8
      Human 31013362IV creatine phosphate disodium
      Creatine phosphate disodium in 50 mL 0.9% saline, IV infusion over 30 min
      		2 g (salt/compound)NR6creatine (Cr, metabolite of PCr) (plasma)AUC
      AUCinf
      		79.01 ± 24.512 (SD)h μg/mLTable 8
      Rodent 25150000PCr 1000 mg/kg iv, healthy mice
      phosphocreatine disodium tetrahydrate (Mr 327, >97% purity)
      		1000 mg/kg (salt/compound)NR5 per time pointphosphocreatine (PCr) (plasma)AUC
      AUC
      		35,845.9 ± 4314.5 (SD)(µg/ml) minTable 1
      Rodent 25150000PCr 1000 mg/kg iv, healthy mice
      phosphocreatine disodium tetrahydrate (Mr 327, >97% purity)
      		1000 mg/kg (salt/compound)NR5 per time pointcreatine (Cr, metabolite) (plasma)AUC
      AUC
      		43,215.7 ± 3556.5 (SD)(µg/ml) minTable 2
      Rodent 25150000PCr 1000 mg/kg iv, healthy mice
      phosphocreatine disodium tetrahydrate (Mr 327, >97% purity)
      		1000 mg/kg (salt/compound)NR5 per time pointcreatine (Cr, metabolite) (plasma)Tmax
      tmax
      		5 minTable 2
      quote mismatch, check
      Rodent 25150000PCr 1000 mg/kg iv, healthy mice
      phosphocreatine disodium tetrahydrate (Mr 327, >97% purity)
      		1000 mg/kg (salt/compound)NR5 per time pointcreatine (Cr, metabolite) (plasma)Cmax
      Cmax
      		853.4 ± 62.3 (SD)µg/mlTable 2
      Rodent 25150000PCr 1000 mg/kg iv, healthy mice
      phosphocreatine disodium tetrahydrate (Mr 327, >97% purity)
      		1000 mg/kg (salt/compound)NR5 per time pointATP (myocardium)AUC
      AUC
      		9286.98 ± 884.67 (SD)(µg/ml) minTable 2
      Rodent 25150000PCr 1000 mg/kg iv, healthy mice
      phosphocreatine disodium tetrahydrate (Mr 327, >97% purity)
      		1000 mg/kg (salt/compound)NR5 per time pointATP (myocardium)Tmax
      tmax
      		90 minTable 2
      Rodent 25150000PCr 1000 mg/kg iv, healthy mice
      phosphocreatine disodium tetrahydrate (Mr 327, >97% purity)
      		1000 mg/kg (salt/compound)NR5 per time pointATP (myocardium)Cmax
      Cmax
      		125.7 ± 3.89 (SD)µg/gTable 2
      Rodent 25150000Cr 456 mg/kg iv (equimolar to PCr 1000 mg/kg), healthy mice
      creatine monohydrate (Mr 149, 98% purity)
      		456 mg/kg (salt/compound)NR5 per time pointcreatine (Cr) (plasma)AUC
      AUC
      		59,845.10 ± 2532.42 (SD)(µg/ml) minTable 3
      Rodent 25150000Cr 456 mg/kg iv (equimolar to PCr 1000 mg/kg), healthy mice
      creatine monohydrate (Mr 149, 98% purity)
      		456 mg/kg (salt/compound)NR5 per time pointcreatine (Cr) (myocardium)Tmax
      tmax
      		60 minTable 4
      Rodent 25150000Cr 456 mg/kg iv (equimolar to PCr 1000 mg/kg), healthy mice
      creatine monohydrate (Mr 149, 98% purity)
      		456 mg/kg (salt/compound)NR5 per time pointcreatine (Cr) (myocardium)Cmax
      Cmax
      		195.0 ± 3.47 (SD)µg/gTable 4
      Rodent 25150000Cr 456 mg/kg iv (equimolar to PCr 1000 mg/kg), healthy mice
      creatine monohydrate (Mr 149, 98% purity)
      		456 mg/kg (salt/compound)NR5 per time pointATP (myocardium)AUC
      AUC
      		5145.75 ± 455.27 (SD)(µg/ml) minTable 4
      Rodent 25150000Cr 456 mg/kg iv (equimolar to PCr 1000 mg/kg), healthy mice
      creatine monohydrate (Mr 149, 98% purity)
      		456 mg/kg (salt/compound)NR5 per time pointATP (myocardium)Tmax
      tmax
      		60 minTable 4
      Rodent 25150000Cr 456 mg/kg iv (equimolar to PCr 1000 mg/kg), healthy mice
      creatine monohydrate (Mr 149, 98% purity)
      		456 mg/kg (salt/compound)NR5 per time pointATP (myocardium)Cmax
      Cmax
      		94.08 ± 2.19 (SD)µg/gTable 4

      Showing 60 of 93 Cmax/Tmax/AUC values (human first). All 95 values are in /api/supplements/creatine.

      References for this section (7)
      1. Human Harris RC, Nevill M, Harris DB, Fallowfield JL, Bogdanis GC, Wise JA. Absorption of creatine supplied as a drink, in meat or in solid form. Journal of sports sciences. 2002;20(2):147-51. PMID 11811571. doi:10.1080/026404102317200855 PubMed · DOI · randomized crossover (Latin square), two separate studies, n=Study 1: 5; Study 2: 5
      2. Human Persky AM, Müller M, Derendorf H, Grant M, Brazeau GA, Hochhaus G. Single- and multiple-dose pharmacokinetics of oral creatine. Journal of clinical pharmacology. 2003;43(1):29-37. PMID 12520625. doi:10.1177/0091270002239703 PubMed · DOI · open-label, multiple-dose, single-arm (single-dose Day 1 then steady state Day 8), n=6
      3. Human Harris RC, Almada AL, Harris DB, Dunnett M, Hespel P. The creatine content of Creatine Serum and the change in the plasma concentration with ingestion of a single dose. Journal of sports sciences. 2004;22(9):851-7. PMID 15513279. doi:10.1080/02640410310001658739 PubMed · DOI · randomized crossover (three sessions, order randomized) plus product composition analysis and a 2-subject sublingual sub-study, n=6 (main); 2 (sublingual)
      4. Human Pittas G, Hazell MD, Simpson EJ, Greenhaff PL. Optimization of insulin-mediated creatine retention during creatine feeding in humans. Journal of sports sciences. 2010;28(1):67-74. PMID 20035494. doi:10.1080/02640410903390071 PubMed · DOI · randomized crossover (double-blind, placebo-controlled per authors), three 3-day trials, n=7
      5. Human Hone M, Kent RM, Scotto di Palumbo A, Bleiel SB, De Vito G, Egan B. Plasma Creatine Kinetics After Ingestion of Microencapsulated Creatine Monohydrate with Enhanced Stability in Aqueous Solutions. Journal of dietary supplements. 2017;14(4):433-445. PMID 28121472. doi:10.1080/19390211.2016.1267060 PubMed · DOI · RCT (randomized, double-blind, parallel, placebo-controlled, single visit), n=10
      6. Human Sun N, Li Q, Zhao L, He H, Zhang M, Wang X. Simultaneous quantitative analysis of phosphocreatine, creatine and creatinine in plasma of children by HPLC-MS/MS method: Application to a pharmacokinetic study in children with viral myocarditis. Biomedical chromatography : BMC. 2019;33(8):e4558. PMID 31013362. doi:10.1002/bmc.4558 PubMed · DOI · single-arm, open-label PK application study, n=6
      7. Rodent Xu L, Wang CY, Lv L, Liu KX, Sun HJ, Han GZ. Pharmacokinetics of phosphocreatine and its active metabolite creatine in the mouse plasma and myocardium. Pharmacological reports : PR. 2014;66(5):908-14. PMID 25150000. doi:10.1016/j.pharep.2014.05.013 PubMed · DOI · parallel (sparse sampling, 5 animals per time point)

      Indirect comparisons (across studies)

      Each form's values come from different human studies that tested one form only. Rows are compared only when parameter, analyte, matrix, fed/fasted state, single vs repeated dosing, AUC interval and units all match, and baseline correction matches where reported (a value with baseline correction not reported is labeled and capped at grade D). Serum and plasma are treated as the same matrix. Ranges are the lowest and highest printed values; nothing is averaged or pooled. Conditions a paper does not state are recorded as NR and never matched.

      Indirect comparison: weighs less than head-to-head evidence; comparisons using values with baseline correction not reported are capped at C. The combined grade for named pairs is shown in the head-to-head section. draft — pending reviewer (Dr. Colin Reily).

      No form pair for this supplement has matched-condition single-form human data yet.

      Pairs that cannot be compared indirectly yet

      • Monohydrate vs HCl: no human single-form arm with a printed value for HCl
      Method
      Indirect (cross-study) PK comparisons from bundle_v2 single-form human arms.
Values are copied as printed. Matching key: parameter, analyte, matrix, fed/fasted, single vs repeated,
AUC interval (from parameter_detail), baseline correction, units (exact). No pooling/averaging: per-form
ranges are min–max of printed values. Analyte for minerals/B12 is classed as total element vs isotope/radiotracer; units compared after removing spaces/separators only; IV arms excluded; serum and plasma treated as the same matrix; curated magnesium v1 rows (mapped from stated conditions only, NR otherwise, deduped against the bundle) are included; baseline correction NR is treated as unknown (may match corrected or uncorrected sets; labeled and capped at C); for % absorption endpoints an unreported baseline correction is treated as not applicable. Normalization: value / elemental dose (mg) ONLY when dose_basis is
'elemental', dose unit is mg, single dose, baseline-corrected=yes, parameter Cmax/AUC. Grade capped at C.
Run after merge_bundle.py.

      Carbs and timing

      Grade BB: solid human data. Forms: 3+ human studies. Comparisons: one randomized head-to-head, or matched single-form evidence from 2+ studies per form. All grades are drafts pending reviewer sign-off.human + animal data · drafthow we gradeSpecies (abstract screen): 3 human, 2 rodent, 3 other animal

      Grade basis (abstract screen): 3 human randomized/crossover studies; A-eligible only once the reviewer confirms they agree (capped at B until then). Auto-computed draft grade — pending reviewer review.

      Show 8 studies with verbatim quotes
      • HumanMethodological Approaches to Bioavailability of Oral Creatine in Randomized Controlled Trials: A Meta-Research Study.
        Nutrients, 2026 · [PMID 42654277]
        • Key findings · abstract:Bioavailability was mentioned in only 38 (11.1%) reports, most frequently in the discussion section.
        • Key findings · abstract:Four trials (1.2%) reported specific measures intended to enhance bioavailability, including instructions regarding supplement dissolution or co-ingestion with food or carbohydrates.
        • Key findings · abstract:Five trials (1.5%) compared more than one creatine formulation, but only three (0.9%) discussed bioavailability.
        • +2 more quotes in Studies
      • HumanEnhanced Absorption and Safety of MuscleBlaze CreAMP™: A Comparative Analysis With Regular Micronized Creatine Monohydrate in Healthy Male Adults.
        Cureus, 2025 · [PMID 40182172]
        • Key findings · abstract:This study evaluated the bioavailability and safety of MuscleBlaze Creatine Monohydrate (CreAMP™) (Bright Lifecare Pvt Ltd, Gurugram, India), containing 3.0 g creatine monohydrate and 0.1 g Creabsorb™ (Indian Patent: IN202311057466), against a standard 3.0 g micronized creatine dose.
        • Key findings · abstract:With a 38.97% increase in bioavailability, an 18.10% higher Cmax, a 21.37% longer half-life, 34.67% lower clearance, and a 10.13% higher mean residence time, CreAMP™ demonstrates superior pharmacokinetic properties.
        • Cmax · abstract:With a 38.97% increase in bioavailability, an 18.10% higher Cmax, a 21.37% longer half-life, 34.67% lower clearance, and a 10.13% higher mean residence time, CreAMP™ demonstrates superior pharmacokinetic properties.
        • +1 more quotes in Studies
      • HumanKinetics of creatine ingested as a food ingredient.
        Eur J Appl Physiol, 2008 · n n = 4 · [PMID 17851680]
        • Key findings · abstract:Seventeen healthy young men ingested 2 g creatine either in the form of AS, or incorporated in a protein (PP)- or in a beta-glucan (BG)-rich food bar.
        • Key findings · abstract:Kinetics of plasma creatine was measured for 8-h duration and urinary excretion for 24 h.
        • Key findings · abstract:Absorption of creatine was slowed down by 8-fold in the presence of BG (P < 0.001) and by 4-fold with PP (P < 0.001) whereas the velocity rate constant of elimination and the area under the curve were not modified.
        • +12 more quotes in Studies
      • RodentEffects of creatine supplementation on homocysteine levels and lipid peroxidation in rats.
        Br J Nutr, 2009 · [PMID 19079843]
        • Key findings · abstract:Plasma Hcy was significantly lower (P < 0.05) in DCr (7.5 (sd 1.2) micromol/l) and CrO + D (7.2 (sd 1.7) micromol/l) groups compared with the control group (12.4 (sd 2.2) micromol/l).
        • Key findings · abstract:Both plasma thiobarbituric acid-reactive species (TBARS) (control, 10 (sd 3.4);[excerpt truncated in our database — see source]
        • Key findings · abstract:CrO + D, 2.4 (sd 1) micromol/l) and plasma total glutathione (control, 4.3 (sd 1.9);[excerpt truncated in our database — see source]
        • +6 more quotes in Studies
      • RodentCreatine uptake in mouse hearts with genetically altered creatine levels.
        J Mol Cell Cardiol, 2008 · [PMID 18602925]
        • Key findings · abstract:Cardiac creatine uptake levels were measured in isolated hearts from creatine-free guanidinoacetate-N-methyl transferase knock out (GAMT(-/-)) mice and from mice overexpressing the myocardial CrT (CrT-OE) using (14)C-radiolabeled creatine.
        • Key findings · abstract:Hearts from GAMT(-/-) mice showed a 7-fold increase in V(max) of creatine uptake and a 1.4-fold increase in CrT mRNA levels.
        • Key findings · abstract:Cardiac creatine uptake levels in CrT-OE mice were increased on average 2.7-fold, showing a considerable variation, in line with a similar variation in creatine content.
        • +9 more quotes in Studies
      • Other animalEffects of dietary guanidinoacetic acid on growth performance, guanidinoacetic acid absorption and creatine metabolism of lambs.
        PLoS One, 2022 · [PMID 35275964]
        • Key findings · abstract:With the increase of dietary GAA level, both Cr concentration in hepatic vein plasma and the portal plasma GAA concentration shows a quadratic change, with the highest concentration in the 500 mg/kg group and the lowest concentration in the 0 mg/kg group.
        • Food effect · abstract:The lambs were fed with the basal diets supplemented with 0 (0 mg/kg group), 500 (500 mg/kg group), 1000 (1000 mg/kg group) and 1500 mg (1500 mg/kg group) GAA per kg diet (DM basis), respectively.
        • Form comparison · full text, Section '3.4 Contents of Cr in hepatic vein, and ':After 4 h of the feeding, the mRNA expression levels of GAMT in GAA supplementation groups was increased compared with that in the 0 mg/kg group, but the values were similar (P>0.05) (Fig 1).
      • Other animalApplication of NMR-based metabonomics suggests a relationship between betaine absorption and elevated creatine plasma concentrations in catheterised sows.
        Br J Nutr, 2012 · [PMID 22673149]
        • Key findings · abstract:The LF diet resulted in a higher betaine concentration in the blood than the two high-fibre diets (P=0·008).
        • Key findings · abstract:This leads to higher plasma concentrations of methionine (P=0·0028) and creatine (P=0·020) of endogenous origin.
        • Food effect · abstract:A total of six sows were fed a diet low in fibre (LF), a diet high in soluble fibre and a diet high in insoluble fibre in a repeated 3 × 3 cross-over design.
        • +5 more quotes in Studies
      • Other animalMuscle creatine uptake and creatine transporter expression in response to creatine supplementation and depletion.
        J Appl Physiol (1985), 2003 · [PMID 12611762]
        • Key findings · abstract:Cr uptake was assessed by skeletal muscle (14)C-Cr accumulation to Cr and PCr by using hindlimb perfusion, and CrT protein content was assessed by Western blot.
        • Key findings · abstract:Cr uptake rate decreased with dietary Cr supplementation in the white gastrocnemius (WG; 45%) only.
        • Key findings · abstract:Depletion of muscle Cr(total) to approximately 15% of normal increased Cr uptake in the soleus (21%) and red gastrocnemius (22%), corresponding to 70-150% increases in muscle CrT content.
        • +2 more quotes in Studies

      Best time to take Creatine

      Not gradedNot graded: no comparable evidence yet. All grades are drafts pending reviewer sign-off.no data · drafthow we gradeSpecies (abstract screen): no studies

      Grade basis (abstract screen): No relevant studies in the database for this question.

      No relevant studies in our database address this question yet. We don't fill gaps with guesses.

      Creatine cost per mg calculator

      Educational information about published research; not medical advice. Not intended to diagnose, treat, cure or prevent any disease. Talk to a clinician before changing supplements, especially if pregnant, nursing or on medication.

      Enter what you pay. We calculate cost per mg, and cost per mg absorbed only as a range and only where a cited, reviewer-verified absorption range exists for that form.

      Cost per mg (from your label): —

      Cost per mg absorbed: not available for this form yet. No reviewer-verified, cited absorption range is in our database, and we won't estimate one.

      This tool compares prices using published ranges. It does not estimate how much you personally absorb and does not recommend a dose. Absorption varies with the person, the dose, food and the product. Not medical advice.

      FAQ

      Is Creatine hcl better absorbed than monohydrate?

      We have no relevant studies in our database that mention both forms, but no graded head-to-head measurement yet. See the verbatim findings in this section. See section →

      Should Creatine be taken with food?

      We have 8 relevant studies in our database that mention food or fasting. See section →

      When is the best time to take Creatine?

      We have no relevant studies in our database that mention timing. See section →

      Is this dosing advice?

      No. We summarize published absorption research and compare prices. Talk to a clinician about what's right for you. See section →

      Answers summarize the data on this page; drafts pending reviewer sign-off.

      Evidence grades

      Rubric v2: single-form human studies count. Hover or focus a grade for what it means; see the methodology. All grades are drafts pending reviewer sign-off.

      QuestionGrade & basisSpecies
      Page grade (best of the grades below)Grade BB: solid human data. Forms: 3+ human studies. Comparisons: one randomized head-to-head, or matched single-form evidence from 2+ studies per form. All grades are drafts pending reviewer sign-off.rubric v2, draft
      Monohydrate: absorption evidenceGrade BB: solid human data. Forms: 3+ human studies. Comparisons: one randomized head-to-head, or matched single-form evidence from 2+ studies per form. All grades are drafts pending reviewer sign-off.
      3 human studies, total n=17, 2 randomized/crossover; consistency not evaluable (no matched set with ≥2 studies)
      		human
      With food (abstract screen)Grade BB: solid human data. Forms: 3+ human studies. Comparisons: one randomized head-to-head, or matched single-form evidence from 2+ studies per form. All grades are drafts pending reviewer sign-off.human + animal data · drafthow we grade
      3 human randomized/crossover studies; A-eligible only once the reviewer confirms they agree (capped at B until then). Auto-computed draft grade — pending reviewer review.
      		3 human, 2 rodent, 3 other animal
      Best time (abstract screen)Not gradedNot graded: no comparable evidence yet. All grades are drafts pending reviewer sign-off.no data · drafthow we grade
      No relevant studies in the database for this question.
      		no studies

      Studies (68)

      Sorted human → primate → pig → rodent → other animal → in vitro. Quotes are verbatim from the abstract or free full text. Paywalled papers: abstract only.

      Show all 68 studies and quotes
      1. HumanComparative Efficacy and Pharmacokinetic Parameters of Micronized Creatine Monohydrate (KleanCREATINE™) in Active Men: A Randomized, Controlled Clinical Study.
        Cureus, 2026 · Design: randomized; crossover; double-blind · n: 10 healthy men · abstract (PubMed); full-text PDF saved · open access (gold)
        PMID 41809290DOI 10.7759/cureus.103091PMC12968080 (free full text)PDF
        Verification: abstract-only auto-extract; unverified
        • Key findings · abstract:Results In Phase I, KleanCREATINE™ demonstrated better pharmacokinetics profile with higher Cmax (8.10 vs 4.80 nmol/UI), quicker Tmax (2 vs 3 hours), and greater relative bioavailability (160.42% in sequence one and 175.45% in sequence two) over the marketed formulation.
        • Key findings · abstract:KleanCREATINE™ showed greater chest press endurance (60.05% vs 49.29%).
        • Cmax · abstract:Results In Phase I, KleanCREATINE™ demonstrated better pharmacokinetics profile with higher Cmax (8.10 vs 4.80 nmol/UI), quicker Tmax (2 vs 3 hours), and greater relative bioavailability (160.42% in sequence one and 175.45% in sequence two) over the marketed formulation.
        • Tmax · abstract:Results In Phase I, KleanCREATINE™ demonstrated better pharmacokinetics profile with higher Cmax (8.10 vs 4.80 nmol/UI), quicker Tmax (2 vs 3 hours), and greater relative bioavailability (160.42% in sequence one and 175.45% in sequence two) over the marketed formulation.
        • Relative bioavailability · abstract:Results In Phase I, KleanCREATINE™ demonstrated better pharmacokinetics profile with higher Cmax (8.10 vs 4.80 nmol/UI), quicker Tmax (2 vs 3 hours), and greater relative bioavailability (160.42% in sequence one and 175.45% in sequence two) over the marketed formulation.
      2. HumanMethodological Approaches to Bioavailability of Oral Creatine in Randomized Controlled Trials: A Meta-Research Study.
        Nutrients, 2026 · Design: randomized · full text (Europe PMC XML) + abstract · open access (gold)
        PMID 42654277DOI 10.3390/nu18162697PMC13516631 (free full text)
        Verification: full-text auto-extracted verbatim snippets with location; needs human check
        • Key findings · abstract:Bioavailability was mentioned in only 38 (11.1%) reports, most frequently in the discussion section.
        • Key findings · abstract:Four trials (1.2%) reported specific measures intended to enhance bioavailability, including instructions regarding supplement dissolution or co-ingestion with food or carbohydrates.
        • Key findings · abstract:Five trials (1.5%) compared more than one creatine formulation, but only three (0.9%) discussed bioavailability.
        • Food effect · abstract:Four trials (1.2%) reported specific measures intended to enhance bioavailability, including instructions regarding supplement dissolution or co-ingestion with food or carbohydrates.
        • Form comparison · full text, Section '3.2. Mentions of Bioavailability':These dosing regimens translate to the daily doses of 20.11 mmol of creatine supplied in the form of creatine monohydrate vs. 7.73 (low dose) or 15.45 mmol (high dose) of creatine provided as creatine nitrate.
      3. HumanRed Blood Cell Creatine as a Biomarker of Systemic Creatine Transport Capacity and Tissue Bioavailability: Toward a Multi-Compartment Framework of Human Bioenergetics.
        Nutr Rev, 2026 · Design: not stated · abstract only (PubMed) · closed/paywalled
        PMID 42752618DOI 10.1093/nutrit/nuag139
        Verification: abstract-only auto-extract; unverified
        • HumanEnhanced Absorption and Safety of MuscleBlaze CreAMP™: A Comparative Analysis With Regular Micronized Creatine Monohydrate in Healthy Male Adults.
          Cureus, 2025 · Design: randomized; crossover; double-blind · abstract only (PubMed) · open access (gold)
          PMID 40182172DOI 10.7759/cureus.81555PMC11966180 (free full text)
          Verification: abstract-only auto-extract; unverified
          • Key findings · abstract:This study evaluated the bioavailability and safety of MuscleBlaze Creatine Monohydrate (CreAMP™) (Bright Lifecare Pvt Ltd, Gurugram, India), containing 3.0 g creatine monohydrate and 0.1 g Creabsorb™ (Indian Patent: IN202311057466), against a standard 3.0 g micronized creatine dose.
          • Key findings · abstract:With a 38.97% increase in bioavailability, an 18.10% higher Cmax, a 21.37% longer half-life, 34.67% lower clearance, and a 10.13% higher mean residence time, CreAMP™ demonstrates superior pharmacokinetic properties.
          • Cmax · abstract:With a 38.97% increase in bioavailability, an 18.10% higher Cmax, a 21.37% longer half-life, 34.67% lower clearance, and a 10.13% higher mean residence time, CreAMP™ demonstrates superior pharmacokinetic properties.
          • Food effect · abstract:In a double-blind, randomized crossover trial (CTRI/2024/08/073021), 32 healthy males (18-50 years) received both formulations under fasting conditions.
        • HumanStructural insights into the substrate uptake and inhibition of the human creatine transporter (hCRT).
          Proc Natl Acad Sci U S A, 2025 · Design: not stated · full text (Europe PMC XML) + abstract · open access (hybrid)
          PMID 40892912DOI 10.1073/pnas.2426135122PMC12435270 (free full text)
          Verification: full text read; no PK numbers matched
          • Key findings · abstract:Here, we report the high-resolution cryo-Electron Microscopy (cryo-EM) structures of human hCRT in three states: apo, creatine-bound, and RGX202-bound. hCRT adopts a canonical LeuT-fold with 12 transmembrane helices and two pseudosymmetric inverted repeats.
          • Relative bioavailability · abstract:Here, we report the high-resolution cryo-Electron Microscopy (cryo-EM) structures of human hCRT in three states: apo, creatine-bound, and RGX202-bound. hCRT adopts a canonical LeuT-fold with 12 transmembrane helices and two pseudosymmetric inverted repeats.
        • HumanSLC6A8-mediated creatine uptake suppresses ERK2-FSP1 signaling and induces ferroptosis in colorectal cancer.
          Cell Rep, 2025 · Design: not stated · abstract only (PubMed) · open access (gold)
          PMID 40892544DOI 10.1016/j.celrep.2025.116139
          Verification: abstract-only auto-extract; unverified
          • Key findings · abstract:Inhibiting the creatine transporter SLC6A8 reduces creatine uptake and activates ERK2.
        • HumanPharmacokinetic Evaluation of a Single 5-Gram Bolus of Creatine Monohydrate Versus Two Other Creatine-Containing Investigational Products.
          Cureus, 2022 · Design: not stated · abstract (PubMed); full-text PDF saved · open access (gold)
          PMID 35619864DOI 10.7759/cureus.24395PMC9126436 (free full text)PDF
          Verification: abstract-only auto-extract; unverified
          • Key findings · abstract:Cmax data indicate that CreaBev 1 10.55±4.10, CreaBev 2 15.45±5.48, and creatine monohydrate 12.77±4.0 nmol/h/μL.
          • Key findings · abstract:The AUC data indicate that CreaBev 1 22.90±9.17, CreaBev 2 33.92±9.52, and creatine monohydrate 29.58±11.93 nmol/h/μL.
          • Key findings · abstract:When examining the data for pharmacokinetics, the AUC and Cmax pharmacokinetics were greatest for CreaBev 2 (p<0.021 and 0.020).
          • Cmax · abstract:Cmax data indicate that CreaBev 1 10.55±4.10, CreaBev 2 15.45±5.48, and creatine monohydrate 12.77±4.0 nmol/h/μL.
          • Cmax · abstract:When examining the data for pharmacokinetics, the AUC and Cmax pharmacokinetics were greatest for CreaBev 2 (p<0.021 and 0.020).
          • Tmax · abstract:The Tmax analysis demonstrated CreaBev 1 1.20±1.01, CreaBev 2 1.23±0.65, and creatine monohydrate 0.91±0.2 h.
          • AUC · abstract:The AUC data indicate that CreaBev 1 22.90±9.17, CreaBev 2 33.92±9.52, and creatine monohydrate 29.58±11.93 nmol/h/μL.
          • AUC · abstract:When examining the data for pharmacokinetics, the AUC and Cmax pharmacokinetics were greatest for CreaBev 2 (p<0.021 and 0.020).
        • HumanLyn regulates creatine uptake in an imatinib-resistant CML cell line.
          Biochim Biophys Acta Gen Subj, 2020 · Design: stable-isotope · abstract only (PubMed) · open access (green)
          PMID 31881245DOI 10.1016/j.bbagen.2019.129507PMC7055176 (free full text)
          Verification: abstract-only auto-extract; unverified
          • Key findings · abstract:Creatine uptake was independent of the Na+/creatine symporter (SLC6A8) expression or de novo synthesis.
        • HumanSimultaneous quantitative analysis of phosphocreatine, creatine and creatinine in plasma of children by HPLC-MS/MS method: Application to a pharmacokinetic study in children with viral myocarditis.
          Biomed Chromatogr, 2019 · Design: not stated · abstract only (PubMed) · closed/paywalled
          PMID 31013362DOI 10.1002/bmc.4558
          Verification: abstract-only auto-extract; unverified
          • Key findings · abstract:A 50 μL aliquot of plasma was prepared by protein precipitation with acetonitrile-water (1000 μL, 1:1, v/v) followed by separation on a Hypersil Gold C18 column (35°C) with gradient mobile phase consisting of 2 mm ammonium acetate aqueous solution (pH 10) and methanol at a flow rate of 0.3 mL/min and analyzed by mass spectrometry in both positive (phosphocreatine) and negative (creatine and creatinine) ion multiple reaction monitoring mode.
          • Key findings · abstract:The pharmacokinetc parameters of phosphocreatine/creatine were as follows: t1/2 0.24/0.83 h, Tmax 0.49/0.55 h, Cmax 47.34/59.29 μg/mL, AUClast 17.07/59.6[excerpt truncated in our database — see source]
          • Cmax · abstract:The pharmacokinetc parameters of phosphocreatine/creatine were as follows: t1/2 0.24/0.83 h, Tmax 0.49/0.55 h, Cmax 47.34/59.29 μg/mL, AUClast 17.07/59.63 h μg/mL, AUCinf 17.16/79.01 h μg/mL and MRT 0.29/0.67 h.
          • Tmax · abstract:The pharmacokinetc parameters of phosphocreatine/creatine were as follows: t1/2 0.24/0.83 h, Tmax 0.49/0.55 h, Cmax 47.34/59.29 μg/mL, AUClast 17.07/59.63 h μg/mL, AUCinf 17.16/79.01 h μg/mL and MRT 0.29/0.67 h.
          • AUC · abstract:The pharmacokinetc parameters of phosphocreatine/creatine were as follows: t1/2 0.24/0.83 h, Tmax 0.49/0.55 h, Cmax 47.34/59.29 μg/mL, AUClast 17.07/59.63 h μg/mL, AUCinf 17.16/79.01 h μg/mL and MRT 0.29/0.67 h.
        • HumanPlasma Creatine Kinetics After Ingestion of Microencapsulated Creatine Monohydrate with Enhanced Stability in Aqueous Solutions.
          J Diet Suppl, 2017 · Design: double-blind · n: n = 5 · abstract only (PubMed) · closed/paywalled
          PMID 28121472DOI 10.1080/19390211.2016.1267060
          Verification: abstract-only auto-extract; unverified
          • Key findings · abstract:Three hours after ingestion, plasma creatine concentrations were unchanged during PLA, and averaged ∼45 μM.
          • Key findings · abstract:During CRE, plasma creatine concentration peaked after 30 min at 101.6 ± 14.9 μM (p < 0.05), representing a 2.3-fold increase over PLA.
          • Key findings · abstract:Thereafter, plasma creatine concentration gradually trended downwards but remained significantly elevated (∼50% above resting levels) 3 hr after ingestion.
          • Relative bioavailability · abstract:During CRE, plasma creatine concentration peaked after 30 min at 101.6 ± 14.9 μM (p < 0.05), representing a 2.3-fold increase over PLA.
        • HumanWhole body creatine and protein kinetics in healthy men and women: effects of creatine and amino acid supplementation.
          Amino Acids, 2016 · Design: clinical trial · abstract only (PubMed) · open access (green)
          PMID 26480831DOI 10.1007/s00726-015-2111-1PMC4754151 (free full text)
          Verification: abstract-only auto-extract; unverified
          • Key findings · abstract:Creatine caused a ten-fold increase in the plasma concentration of creatine and a 50 % decrease in the concentration of guanidinoacetic acid.
          • Relative bioavailability · abstract:Creatine caused a ten-fold increase in the plasma concentration of creatine and a 50 % decrease in the concentration of guanidinoacetic acid.
        • HumanEffect of Creatine Loading on Oxygen Uptake during a 1-km Cycling Time Trial.
          Med Sci Sports Exerc, 2015 · Design: randomized; double-blind · n: n = 10 · abstract only (PubMed) · closed/paywalled
          PMID 26083771DOI 10.1249/MSS.0000000000000718
          Verification: abstract-only auto-extract; unverified
          • Key findings · abstract:PURPOSE: For the first time, we investigated the effects of altering cellular metabolic capacitance, via a 5-d creatine (Cr) loading protocol (20 g·d⁻¹), on oxygen uptake (VO2), accumulated oxygen deficit, muscle recruitment, and performance during a 1-km cycling time trial.
          • Key findings · abstract:The VO2 mean response time was slower (pre: 17.2 ± 5.6 s vs post: 19.9 ± 4.6 s), the total O2 uptake was reduced (pre: 4.64 ± 0.59 L vs post: 4.47 ± 0.53 L), and the oxygen deficit was increased (pre: 0.82 ± 0.27 L vs post: 0.98 ± 0.25 L) after Cr loading.
          • Key findings · abstract:Plasma lactate and integrated electromyography were not altered[excerpt truncated in our database — see source]
        • HumanCreatine-induced glucose uptake in type 2 diabetes: a role for AMPK-α?
          Amino Acids, 2012 · Design: randomized · n: n = 10 · abstract only (PubMed) · closed/paywalled
          PMID 22349765DOI 10.1007/s00726-012-1246-6
          Verification: abstract-only auto-extract; unverified
          • Key findings · abstract:This study focused on understanding the signaling mechanisms leading to GLUT-4 translocation and increased skeletal-muscle glucose uptake that follow creatine (Cr) supplementation in type 2 diabetes (n = 10).
          • Key findings · abstract:AMPK-α protein content presented a tendency to be higher (p = 0.06) after Cr supplementation (5 g/d for 12w).
          • Key findings · abstract:The changes in AMPK-α protein content significantly related (p < 0.001) to the changes in GLUT-4 translocation (r = 0.78) and Hb1Ac levels (r = -0.68), suggesting that AMPK signaling may be implicated in the effects of supplementation on glucose uptake in type 2 diabetes.
        • HumanA phase I, pharmacokinetic, dosage escalation study of creatine monohydrate in subjects with amyotrophic lateral sclerosis.
          Amyotroph Lateral Scler, 2010 · Design: not stated · abstract only (PubMed) · open access (green)
          PMID 20698808DOI 10.3109/17482961003797130PMC3045755 (free full text)
          Verification: abstract-only auto-extract; unverified
          • Key findings · abstract:The objectives of this study were to establish steady-state plasma pharmacokinetics of creatine at several dosages, and to evaluate the effects of creatine on brain metabolites using proton magnetic resonance spectroscopy ((1)H-MRS).
          • Key findings · abstract:Mean pre-dose steady-state creatine plasma concentrations were 20.3, 39.3, and 61.5 ug/ml at 5, 10, and 15 g b.i.d., respectively.
          • Key findings · abstract:Creatine spectra increased by 8% (p = 0.06) and glutamate + glutamine signals decreased by 17% (p = 0.039) at higher dosages.
        • HumanOptimization of insulin-mediated creatine retention during creatine feeding in humans.
          J Sports Sci, 2010 · Design: randomized · abstract only (PubMed) · closed/paywalled
          PMID 20035494DOI 10.1080/02640410903390071
          Verification: abstract-only auto-extract; unverified
          • Key findings · abstract:After administration of the first and third bolus, serum insulin concentration was increased by 15 min (P < 0.05) in the creatine + carbohydrate and creatine + protein, amino acids, and carbohydrate trials compared with creatine alone, and plasma creatine increased more following creatine alone (15 min, P < 0.05) than in the creatine + carbohydrate and creatine + protein, amino acids, and carbohydrate trials.
          • Key findings · abstract:Urinary creatine excretion was greater with creatine alone (P < 0.05) than with creatine + carbohydrate and creatine + protein, amino acids, and carbohydrate.
        • HumanThe effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels.
          J Int Soc Sports Nutr, 2009 · Design: double-blind · full text (Europe PMC XML) + abstract · open access (gold)
          PMID 19228401DOI 10.1186/1550-2783-6-6PMC2649889 (free full text)
          Verification: full-text auto-extracted verbatim snippets with location; needs human check
          • Key findings · abstract:This study examined how a seven-week supplementation regimen combined with resistance training affected body composition, muscle mass, muscle strength and power, serum and muscle creatine levels, and serum creatinine levels in 30 non-resistance-trained males.
          • Key findings · abstract:Results showed significantly higher serum creatine concentrations in PLA (p = 0.007) and CRT (p = 0.005) compared to CEE.
          • Key findings · abstract:Serum creatinine was greater in CEE compared to the PLA (p = 0.001) and CRT (p = 0.001) and increased at days 6, 27, and 48.
          • Key findings · abstract:Total muscle creatine content was significantly higher in CRT (p = 0.026) and CEE (p =[excerpt truncated in our database — see source]
          • Form comparison · full text, Section 'Serum Creatinine':Blood draws were not taken specifically after supplementation, yet serum creatinine levels were approximately tripled at day 6 (2.68 ± SD 1.53 mg/dL) compared to baseline (0.95 ± SD 0.18 mg/dL) for the CEE group.
        • HumanQualitative in vitro NMR analysis of creatine ethyl ester pronutrient in human plasma.
          Int J Sports Med, 2009 · Design: not stated · abstract only (PubMed) · closed/paywalled
          PMID 19585404DOI 10.1055/s-0029-1231045
          Verification: abstract-only auto-extract; unverified
          • Key findings · abstract:Lyophilized human plasma was reconstituted in D2O and phosphate-buffered saline and 1.5 mg of the analyte was added.
        • HumanUrinary creatine and methylamine excretion following 4 x 5 g x day(-1) or 20 x 1 g x day(-1) of creatine monohydrate for 5 days.
          J Sports Sci, 2009 · Design: not stated · n: n = 6 · abstract only (PubMed) · closed/paywalled
          PMID 19437189DOI 10.1080/02640410902838237
          Verification: abstract-only auto-extract; unverified
          • Key findings · abstract:In this study, we examined the effect of two creatine monohydrate supplementation regimes on 24-h urinary creatine and methylamine excretion.
          • Key findings · abstract:Less creatine was excreted following the 20 x 1 g x day(-1) regime (49.25 +/- 10.53 g) than the 4 x 5 g x day(-1) regime (62.32 +/- 9.36 g) (mean +/- s;[excerpt truncated in our database — see source]
          • Key findings · abstract:Mean total excretion of methylamine (n = 6) over days 3-7 was 8.61 +/- 7.58 mg and 24.81 +/- 25.76 mg on the 20 x 1 g x day(-1) and 4 x 5 g x day(-1) regimes, respectively (P < 0.05).
          • Key findings · abstract:The lower excretion of creatine using 20 x 1 g x day(-1) doses suggests a greater retention in the body and most pr[excerpt truncated in our database — see source]
        • HumanInfluence of dietary creatine supplementation on muscle phosphocreatine kinetics during knee-extensor exercise in humans.
          Am J Physiol Regul Integr Comp Physiol, 2009 · Design: clinical trial · abstract only (PubMed) · closed/paywalled
          PMID 19211722DOI 10.1152/ajpregu.90896.2008
          Verification: abstract-only auto-extract; unverified
          • HumanKinetics of creatine ingested as a food ingredient.
            Eur J Appl Physiol, 2008 · Design: crossover · n: n = 4 · abstract (PubMed); full-text PDF saved · open access (green)
            PMID 17851680DOI 10.1007/s00421-007-0558-9PDF
            Verification: full-text auto-extracted verbatim snippets with location; needs human check
            • Key findings · abstract:Seventeen healthy young men ingested 2 g creatine either in the form of AS, or incorporated in a protein (PP)- or in a beta-glucan (BG)-rich food bar.
            • Key findings · abstract:Kinetics of plasma creatine was measured for 8-h duration and urinary excretion for 24 h.
            • Key findings · abstract:Absorption of creatine was slowed down by 8-fold in the presence of BG (P < 0.001) and by 4-fold with PP (P < 0.001) whereas the velocity rate constant of elimination and the area under the curve were not modified.
            • Key findings · abstract:Urinary loss of creatine in the first 24 h following ingestion was 15 +/- 1.9% in AS and 14 +/- 2.2% in PP conditions (NS), whereas it was[excerpt truncated in our database — see source]
            • AUC · abstract:Absorption of creatine was slowed down by 8-fold in the presence of BG (P < 0.001) and by 4-fold with PP (P < 0.001) whereas the velocity rate constant of elimination and the area under the curve were not modified.
            • Relative bioavailability · abstract:Absorption of creatine was slowed down by 8-fold in the presence of BG (P < 0.001) and by 4-fold with PP (P < 0.001) whereas the velocity rate constant of elimination and the area under the curve were not modified.
            • Tmax · full text, p.5:l AS (n = 7) AS (n = 17) BG (n = 17) PP (n = 17) Peak concentration of plasma creatine (observed, lM) 312 ± 41.5 299 ± 19.5 174 ± 14.0*** 237 ± 22.3* Time to peak concentration (observed, h) 0.86 ± 0.092 0.81 ± 0.050 2.40 ± 0.177*** 1.31 ± 0.146* Lag-time (h) 0.42 ± 0.060 0.38 ± 0.033 0.78 ± 0.114*** 0.43 ± 0.060 Velocity constant of absorption (h–1) 25.44 ± 8.780 23.63 ± 6.655 0.78 ± 0.045*** 4.5
            • AUC · full text, p.1:ican College of Sports Medicine esti- whereas the velocity rate constant of elimination and the mated that 2,500 metric tons were consumed every year area under the curve were not modified. Urinary loss of (Terjung et al. 2000). Creatine improves sport performance creatine in the first 24 h following ingestion was during repeated short-duration/high-intensity exercises 15 ± 1.9% in AS and 14 ± 2.2
            • AUC · full text, p.4:artmental model in which ka, kel and tlag are the primary parameters. Knowing their value, new kinetic parameters of plasma creatine were calculated. AUC0,? is the area under the curve integrated from zero to infinity. Since the bio- availability (F) may not be measured, only the apparent volume of distribution and the apparent clearance can be Fig. 2 Percentage of initial dose of creatine (2 g) e
            • AUC · full text, p.5:le 2). The areas under the curve cal- yielded the best fitting of the plasma creatine time-course culated by integration of Eq. 1 from 0 to infinity (AUC0,?) (Fig. 4). Other tested models did not allow the algorithm were identical for all creatine forms (mean value: converging or gave larger residuals. Using Eq. 1, the median 539 ± 30.4 lM h, Table 2). value of residuals was 1.06 lM in AS conditio
            • Relative bioavailability · full text, p.1:s were interspaced by a 40 ± 1.2-day wash-out. Absorption Since the paper of Harris et al. (1992), creatine has become of creatine was slowed down by 8-fold in the presence of one of the most popular dietary supplements in the world. BG (P \ 0.001) and by 4-fold with PP (P \ 0.001) In 2000, the American College of Sports Medicine esti- whereas the velocity rate constant of elimination and the mate
            • Food effect · full text, p.8:tration. The lag-time was 0.38 ± 0.033 and creatine would be taken up first by the liver and therefore, 0.43 ± 0.060 h after ingestion of creatine in fasted state most of the creatine ingested would appear in arterial under AS and PP forms, respectively, but was doubled with blood. However, creatine is obviously taken up by different BG-rich bar (0.78 ± 0.114 h, P \ 0.001). This indicates that cel
            • Form comparison · full text, p.1:or fies creatine plasma kinetics, erythrocyte retention and creatinine was detectable in feces. No side effects were loss in urine and in feces when compared with its con- reported. In conclusion, ingestion of creatine combined sumption in the form of an aqueous solution (AS). with BG facilitates its retention by slowing down its Seventeen healthy young men ingested 2 g creatine either absorption
            • Form comparison · full text, p.2:er about 15 days (Hultman et al. erythrocyte retention and loss in urine and in feces when 1996). Other cell types, such as erythrocytes and neurons, compared to its supplementation in aqueous solution (AS). also store creatine during supplementation (Dechent et al. 1999; Preen et al. 2005). Nevertheless, the level of accu- mulation is not necessarily correlated between tissues (Preen Materials an
            • Form comparison · full text, p.4:el representing creatine was excreted after the BG treatment (8 ± 1.2%, the order of the treatments (first, second or third treatment) P = 0.004), as compared to AS and PP forms. Most of the and when applicable, the time of measurement (pre- and excreted creatine appeared in urine during the first 2 h post-treatment). When the variable tested was not affected following intake of AS (Table 1). Afte
          • HumanCreatine supplementation reduces plasma levels of pro-inflammatory cytokines and PGE2 after a half-ironman competition.
            Amino Acids, 2008 · Design: randomized; double-blind · n: n = 6 · abstract only (PubMed) · closed/paywalled
            PMID 17917696DOI 10.1007/s00726-007-0582-4
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:OBJECTIVE: The effect of creatine supplementation upon plasma levels of pro-inflammatory cytokines: Interleukin (IL) 1 beta and IL-6, Tumor Necrosis Factor alpha (TNFalpha), and Interferon alpha (INF alpha) and Prostaglandin E(2) (PGE(2)) after a half-ironman competition were investigated.
            • Key findings · abstract:RESULTS: Forty-eight hours prior to competition there was no difference between groups in the plasma concentrations (pg x ml(-1), mean +/- SEM) of IL-6 (7.08 +/- 0.63), TNFalpha (76.50 +/- 5.60), INF alpha (18.32 +/- 1.20), IL-1 beta (23.42 +/- 5.52), and PGE(2) (39.71 +/- 3.8).
            • Key findings · abstract:Twenty-four and 48 h afte[excerpt truncated in our database — see source]
          • HumanComparison of new forms of creatine in raising plasma creatine levels.
            J Int Soc Sports Nutr, 2007 · Design: crossover · full text (Europe PMC XML) + abstract · open access (gold)
            PMID 17997838DOI 10.1186/1550-2783-4-17PMC2206055 (free full text)
            Verification: full-text auto-extracted verbatim snippets with location; needs human check
            • Key findings · abstract:RESULTS: Mean peak concentrations and area under the curve (AUC) were significantly higher with CrPyr (17 and 14%, respectively) in comparison to CrM and CrC.
            • Key findings · abstract:Differences in bioavailability are thought to be unlikely since absorption of CrM is already close to 100%.
            • AUC · abstract:RESULTS: Mean peak concentrations and area under the curve (AUC) were significantly higher with CrPyr (17 and 14%, respectively) in comparison to CrM and CrC.
            • AUC · full text, Section 'Results':Mean AUC with CrPyr was 1.14 fold higher compared to CrC although the difference did not reach the threshold of significance (P = 0.069).
            • Form comparison · full text, Section 'Results':Mean peak concentrations were 1.17 fold higher with CrPyr compared to CrC (p = 0.010) and 1.29 fold higher than with CrM, but again missing the threshold of significance (p = 0.075, table 3).
            • Form comparison · full text, Section 'Results':Mean AUC with CrPyr was 1.14 fold higher compared to CrC although the difference did not reach the threshold of significance (P = 0.069).
          • HumanEffect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisol.
            Psychopharmacology (Berl), 2006 · Design: clinical trial · n: n=10 · abstract only (PubMed) · closed/paywalled
            PMID 16416332DOI 10.1007/s00213-005-0269-z
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:They were tested for plasma concentrations of catecholamines and cortisol at 0 and 24 h.
            • Key findings · abstract:Norepinephrine and dopamine concentrations were significantly higher at 24 h than 0 h, but cortisol were lower.
          • HumanOverexpression of wild-type creatine transporter (SLC6A8) restores creatine uptake in primary SLC6A8-deficient fibroblasts.
            J Inherit Metab Dis, 2006 · Design: not stated · abstract only (PubMed) · closed/paywalled
            PMID 16763899DOI 10.1007/s10545-006-0271-6
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:In the study reported, we prove that mutations in the SLC6A8 gene are responsible for SLC6A8 deficiency, a cerebral creatine deficiency syndrome (CCDS), since overexpression of the wild-type SLC6A8 open reading frame (ORF) restores the creatine uptake profile in SLC6A8-deficient fibroblasts.
          • HumanCreatine in Huntington disease is safe, tolerable, bioavailable in brain and reduces serum 8OH2'dG.
            Neurology, 2006 · Design: randomized; double-blind · n: 64 subjects · abstract only (PubMed) · closed/paywalled
            PMID 16434666DOI 10.1212/01.wnl.0000194318.74946.b6
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:Serum 8-hydroxy-2'-deoxyguanosine (8OH2'dG) levels, an indicator of oxidative injury to DNA, were markedly elevated in HD and reduced by creatine treatment.
          • HumanThe creatine content of Creatine Serum and the change in the plasma concentration with ingestion of a single dose.
            J Sports Sci, 2004 · Design: randomized · abstract only (PubMed) · closed/paywalled
            PMID 15513279DOI 10.1080/02640410310001658739
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:(B) 2.5 g creatine monohydrate (Cr.H2O) in solution; and (C) 5 ml Creatine Serum (reportedly containing an equivalent amount of Cr.H2O).
            • Key findings · abstract:Blood samples were collected before and up to 8 h after each treatment and plasma was analysed for creatine and creatinine.
            • Key findings · abstract:Ingestion of 2.5 g creatine monohydrate in solution resulted in a significant increase in plasma creatine (from 59.1+/-11.8 micromol.l(-1) to 245.3+/-74.6 microM micromol.l(-1); mean+/-s) and urinary creatine excretion.
            • Key findings · abstract:Analysis showed 5 ml of Creatine Serum to contain <10 mg Cr.H2O and approximately 90 mg creatinine.
          • HumanGuanidinoacetate methyltransferase deficiency: differences of creatine uptake in human brain and muscle.
            Mol Genet Metab, 2004 · Design: not stated · abstract only (PubMed) · closed/paywalled
            PMID 15234333DOI 10.1016/j.ymgme.2004.04.005
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:Investigation of skeletal muscle by proton and phosphorus magnetic resonance spectroscopy before therapy demonstrated the presence of considerable amounts of creatine and phosphocreatine, and accumulation of phosphorylated guanidinoacetate in a 7-year-old boy diagnosed with GAMT deficiency, suggesting separate mechanisms for creatine uptake and synthesis in brain and skeletal muscle.
          • HumanSingle- and multiple-dose pharmacokinetics of oral creatine.
            J Clin Pharmacol, 2003 · Design: clinical trial · abstract only (PubMed) · closed/paywalled
            PMID 12520625DOI 10.1177/0091270002239703
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:After the single oral dose, the clearance (CL/F) was 0.20 +/- 0.066 L h-1 kg-1, tmax was 1.9 +/- 0.88 hours, and Cmax = 102.1 +/- 11.2 mg h L-1.
            • Key findings · abstract:At steady-state, CL/F decreased to 0.12 +/- 0.016 L h-1 kg-1, tmax did not change, and Cmax increased to 162.2 +/- 30.0 mg L-1.
            • Key findings · abstract:Penetration (AUCMUSCLE/AUCPLASMA) of Cr into the interstitial muscle space, as determined by microdialysis, was 0.47 +/- 0.09 and 0.37 +/- 0.27 for the single dose and at steady-state, respectively.
            • Cmax · abstract:After the single oral dose, the clearance (CL/F) was 0.20 +/- 0.066 L h-1 kg-1, tmax was 1.9 +/- 0.88 hours, and Cmax = 102.1 +/- 11.2 mg h L-1.
            • Cmax · abstract:At steady-state, CL/F decreased to 0.12 +/- 0.016 L h-1 kg-1, tmax did not change, and Cmax increased to 162.2 +/- 30.0 mg L-1.
            • Tmax · abstract:After the single oral dose, the clearance (CL/F) was 0.20 +/- 0.066 L h-1 kg-1, tmax was 1.9 +/- 0.88 hours, and Cmax = 102.1 +/- 11.2 mg h L-1.
            • Tmax · abstract:At steady-state, CL/F decreased to 0.12 +/- 0.016 L h-1 kg-1, tmax did not change, and Cmax increased to 162.2 +/- 30.0 mg L-1.
            • AUC · abstract:Penetration (AUCMUSCLE/AUCPLASMA) of Cr into the interstitial muscle space, as determined by microdialysis, was 0.47 +/- 0.09 and 0.37 +/- 0.27 for the single dose and at steady-state, respectively.
          • HumanCreatine supplementation: a comparison of loading and maintenance protocols on creatine uptake by human skeletal muscle.
            Int J Sport Nutr Exerc Metab, 2003 · Design: randomized · abstract only (PubMed) · closed/paywalled
            PMID 12660409DOI 10.1123/ijsnem.13.1.97
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:Twenty-four hour urine samples were collected for each of the loading days and last 2 maintenance days, and used to determine whole body Cr retention.
            • Key findings · abstract:The Glucose+Cr condition produced a greater elevation (p <.05) in TCr concentrations (25%) than the Cr Only (16%) or Exercise+Cr (18%) groups.
          • HumanAbsorption of creatine supplied as a drink, in meat or in solid form.
            J Sports Sci, 2002 · Design: randomized · abstract only (PubMed) · closed/paywalled
            PMID 11811571DOI 10.1080/026404102317200855
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:We examined the plasma concentration curve obtained over 6 h after the ingestion of 2 g of creatine (Cr) (equivalent to 2.3 g Cr x H2O) contained in meat or in solution in five non-users of creatine supplements.
            • Key findings · abstract:In a separate study, we examined the plasma concentration time curve after ingestion of solid Cr x H2O.
            • Key findings · abstract:Creatine ingested as a lozenge (crushed in the mouth and swallowed) or as a crystalline suspension in ice cold water resulted in a 20% lower peak concentration and 30-35% smaller area under the plasma creatine concentration curve than the same dose administered in solution.
            • Key findings · abstract:Des[excerpt truncated in our database — see source]
            • AUC · abstract:Creatine ingested as a lozenge (crushed in the mouth and swallowed) or as a crystalline suspension in ice cold water resulted in a 20% lower peak concentration and 30-35% smaller area under the plasma creatine concentration curve than the same dose administered in solution.
            • Relative bioavailability · abstract:Despite a possibly lower bioavailability, 2.3 g Cr x H2O supplied in either solid form was nonetheless sufficient to raise the plasma concentration five- to six-fold in individuals with a mean body mass of 75.6 kg.
          • HumanEffect of creatine supplementation on oxygen uptake kinetics during submaximal cycle exercise.
            J Appl Physiol (1985), 2002 · Design: crossover · n: 7 men · abstract only (PubMed) · closed/paywalled
            PMID 12015375DOI 10.1152/japplphysiol.01065.2001
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:The purpose of this study was to test the effect of oral creatine (Cr) supplementation on pulmonary oxygen uptake (VO(2)) kinetics during moderate [below ventilatory threshold (VT)] and heavy (above VT) submaximal cycle exercise.
          • HumanEvaluation of creatine transport using Caco-2 monolayers as an in vitro model for intestinal absorption.
            J Pharm Sci, 2001 · Design: not stated · abstract only (PubMed) · closed/paywalled
            PMID 11745717DOI 10.1002/jps.1109
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:In the present study, creatine transport was examined using Caco-2 monolayers as an in vitro model for intestinal absorption.
          • HumanEffects of acute creatine monohydrate supplementation on leucine kinetics and mixed-muscle protein synthesis.
            J Appl Physiol (1985), 2001 · Design: randomized · n: n = 13 · abstract only (PubMed) · closed/paywalled
            PMID 11509496DOI 10.1152/jappl.2001.91.3.1041
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:A primed-continuous intravenous infusion of L-[1-(13)C]leucine and mass spectrometry were used to measure mixed-muscle protein fractional synthetic rate and indexes of whole body leucine metabolism (nonoxidative leucine disposal), leucine oxidation, and plasma leucine rate of appearance.
            • Key findings · abstract:CrM supplementation did not increase muscle fractional synthetic rate but reduced leucine oxidation (-19.6%) and plasma leucine rate of appearance (-7.5%, P < 0.05) in men, but not in women.
          • HumanCreatine enhances oxygen uptake and performance during alternating intensity exercise.
            Med Sci Sports Exerc, 2000 · Design: randomized · abstract only (PubMed) · closed/paywalled
            PMID 10694120DOI 10.1097/00005768-200002000-00018
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:Oxygen uptake was measured using a breath-by-breath system during bicycle exercise alternating every 3 min between bouts at 30%(-30%) and 90% (-90%) of the maximal power output to exhaustion.
            • Key findings · abstract:Blood ammonia accumulation at the end of 1-90% (23.1 +/- 6.5 micromol x L(-1)) and 3-30% (64.7 +/- 15.2 micromol x L(-1)) was lower after CR (P < 0.05), whereas plasma uric acid accumulation was lower at exhaustion (P < 0.05) and 5-min postexercise (P < 0.01).
          • HumanCyclosporin A inhibits creatine uptake by altering surface expression of the creatine transporter.
            J Biol Chem, 2000 · Design: not stated · abstract only (PubMed) · open access (hybrid)
            PMID 10964923DOI 10.1074/jbc.M005636200
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:The immunosuppressive drug cyclosporin A (CsA) inhibited the hCRT-1 cDNA-induced creatine uptake in Xenopus oocytes and the endogenous creatine uptake in cultured C(2)C(12) muscle cells in a dose- and time-dependent manner.
            • Key findings · abstract:Although CsA treatment did not affect the K(m) (20-24 microm) for creatine, it significantly decreased the V(max) of creatine uptake in both oocytes and muscle cells.
            • Key findings · abstract:CsA treatment reduced the cell surface expression level of the creatine transporter in the muscle cells by approximately 60% without significantly altering its total expression level, and the reduction in[excerpt truncated in our database — see source]
          • RodentEffects of Low Doses of L-Carnitine Tartrate and Lipid Multi-Particulate Formulated Creatine Monohydrate on Muscle Protein Synthesis in Myoblasts and Bioavailability in Humans and Rodents.
            Nutrients, 2021 · Design: randomized · abstract only (PubMed) · open access (gold)
            PMID 34836240DOI 10.3390/nu13113985PMC8625796 (free full text)
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:When Wistar rats were administered creatine with LMP formulation at either 21 or 51 mg/kg, bioavailability was increased by 27% based on the increase in the area under the curve (AUC) at a 51 mg/kg dose compared to without LMP formulation.
            • Key findings · abstract:Finally, in human subjects, a combination of LMP formulated L-carnitine at 500 mg (from L-carnitine tartrate) with LMP formulated creatine at 100, 200, or 500 mg revealed a significant and dose-dependent increase in plasma creatine concentrations.
            • AUC · abstract:When Wistar rats were administered creatine with LMP formulation at either 21 or 51 mg/kg, bioavailability was increased by 27% based on the increase in the area under the curve (AUC) at a 51 mg/kg dose compared to without LMP formulation.
          • RodentSex- and tissue-dependent creatine uptake in response to different creatine monohydrate doses in male and female Sprague-Dawley rats.
            Appl Physiol Nutr Metab, 2021 · Design: not stated · n: n = 32 · abstract (PubMed); full-text PDF saved · open access (hybrid)
            PMID 34171201DOI 10.1139/apnm-2021-0301PDF
            Verification: full text read; no PK numbers matched
            • Key findings · abstract:Total creatine (TCr) concentrations in female white fibre-dominant gastrocnemius (WGAS) and cardiac muscle (HRT) were significantly higher compared with males (p < 0.05).
          • RodentAbsolute Oral Bioavailability of Creatine Monohydrate in Rats: Debunking a Myth.
            Pharmaceutics, 2018 · Design: not stated · abstract only (PubMed) · open access (gold)
            PMID 29518030DOI 10.3390/pharmaceutics10010031PMC5874844 (free full text)
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:Plasma and tissue levels of 13C-labeled creatine were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS).
            • Key findings · abstract:Absolute oral bioavailability for low dose CM was 53% while high dose CM was only 16%.
            • Key findings · abstract:The simulated Cmax of 70 mg/kg CHCL was around 35 μg/mL compared to 14 μg/mL for CM with a predicted oral bioavailability of 66% with CHCL compared to 17% with CM.
            • Cmax · abstract:The simulated Cmax of 70 mg/kg CHCL was around 35 μg/mL compared to 14 μg/mL for CM with a predicted oral bioavailability of 66% with CHCL compared to 17% with CM.
          • RodentEffect of creatine monohydrate supplementation on relative serum level of IL-6 and IL-18 following neonatal hypoxia ischemia in male albino mouse.
            Pak J Pharm Sci, 2015 · Design: not stated · abstract only (PubMed) · unknown
            PMID 26639507
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:In the present study, we tried to determine whether 2% Creatine monohydrate supplementation for variable duration influence the IL-6 and 18 concentrations in the serum of male albino mouse following right common carotid artery ligation and hypoxia (8% oxygen) for 25 minutes.
            • Key findings · abstract:Our result revealed that serum concentration of IL6 (P=0.0001) as well as IL-18 (P=0.003) were significantly higher in mice supplemented with creatine monohydrate for 15 weeks than in male albino mice on normal rodent diet following hypoxic ischemic insult indicating that long term creatine monohydrate supplementation up[excerpt truncated in our database — see source]
          • RodentPharmacokinetics of phosphocreatine and its active metabolite creatine in the mouse plasma and myocardium.
            Pharmacol Rep, 2014 · Design: not stated · abstract only (PubMed) · closed/paywalled
            PMID 25150000DOI 10.1016/j.pharep.2014.05.013
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:Following iv PCr, Cr appeared in plasma as early as 1.0 min postdose with a longer t1/2 than PCr and had a fm of 72%.
            • Key findings · abstract:The mice dosed iv PCr preceded 5 min by ip Pit 30 U/kg showed longer t1/2β PCr and t1/2 Cr in plasma and elevated Cmax, Cr and Cmax, ATP in myocardium compared with mice dosed iv PCr alone, and it was estimated that about 40% ATP produced by iv PCr was from Cr.
            • Cmax · abstract:The mice dosed iv PCr preceded 5 min by ip Pit 30 U/kg showed longer t1/2β PCr and t1/2 Cr in plasma and elevated Cmax, Cr and Cmax, ATP in myocardium compared with mice dosed iv PCr alone, and it was estimated that about 40% ATP produced by iv PCr was from Cr.
          • RodentEffects of creatine supplementation on homocysteine levels and lipid peroxidation in rats.
            Br J Nutr, 2009 · Design: not stated · abstract (PubMed); full-text PDF saved · open access (bronze)
            PMID 19079843DOI 10.1017/S0007114508162985PDF
            Verification: full-text auto-extracted verbatim snippets with location; needs human check
            • Key findings · abstract:Plasma Hcy was significantly lower (P < 0.05) in DCr (7.5 (sd 1.2) micromol/l) and CrO + D (7.2 (sd 1.7) micromol/l) groups compared with the control group (12.4 (sd 2.2) micromol/l).
            • Key findings · abstract:Both plasma thiobarbituric acid-reactive species (TBARS) (control, 10 (sd 3.4);[excerpt truncated in our database — see source]
            • Key findings · abstract:CrO + D, 2.4 (sd 1) micromol/l) and plasma total glutathione (control, 4.3 (sd 1.9);[excerpt truncated in our database — see source]
            • Key findings · abstract:In addition, Hcy showed significant negative correlation (P < 0.05) with plasma creatine (r - 0.61) and positive correlation with plasma TBARS (r 0.74).
            • Key findings · abstract:Plasma creatine was negatively correlated with plasma TBARS (r - 0.75) and total peroxide[excerpt truncated in our database — see source]
            • Food effect · full text, p.5:detected significant reductions plementation can reduce Hcy levels, but these results have not in plasma Hcy levels in a group of nephrectomised rats fed been reproduced in human subjects. 2 % creatine for 2 weeks, as well as a significant negative cor- Creatine supplementation was associated with a decrease in relation between Hcy and plasma creatine. folate concentration, different from Taes et
            • Form comparison · full text, p.1:or 5 d þ 2 % in the diet for 23 d). Plasma Hcy was significantly lower (P,0·05) in DCr (7·5 (SD 1·2) mmol/l) and CrO þ D (7·2 (SD 1·7) mmol/l) groups compared with the control group (12·4 (SD 2·2) mmol/l). Both plasma thiobarbituric acid-reactive species (TBARS) (control, 10 (SD 3·4); DCr, 4·9 (SD 0·7); CrO þ D, 2·4 (SD 1) mmol/l) and plasma total glutathione (control, 4·3 (SD 1·9); DCr, 2·5 (SD 0
            • Form comparison · full text, p.3:and in phosphocreatine concentrations for the DCr (dietary bances defined as A2 and B2. Creatine concentration was creatine only) and CrO þ D groups compared with the control calculated by the formula (A1 2 B1) 2 (A2 2 B2) using a group. A significant increase of total creatine was observed standard curve of 5 to 1000 mM -creatine carried out in tripli- only in the CrO þ D group. cate. To determin
            • Form comparison · full text, p.4:etary creatine ( ) and creatine overload plus diet (K). cant reductions in plasma Hcy concentrations were observed in both the DCr and CrO þ D groups compared with the supplementation reduces plasma Hcy levels in rats. Although control group, with no changes in methionine concentra- no difference was detected between DCr and CrO þ D tion (Fig. 2 (B)), and significant negative correlations were ani
          • RodentCreatine uptake in mouse hearts with genetically altered creatine levels.
            J Mol Cell Cardiol, 2008 · Design: not stated · full text (Europe PMC XML) + abstract · open access (hybrid)
            PMID 18602925DOI 10.1016/j.yjmcc.2008.05.023PMC2568826 (free full text)
            Verification: full-text auto-extracted verbatim snippets with location; needs human check
            • Key findings · abstract:Cardiac creatine uptake levels were measured in isolated hearts from creatine-free guanidinoacetate-N-methyl transferase knock out (GAMT(-/-)) mice and from mice overexpressing the myocardial CrT (CrT-OE) using (14)C-radiolabeled creatine.
            • Key findings · abstract:Hearts from GAMT(-/-) mice showed a 7-fold increase in V(max) of creatine uptake and a 1.4-fold increase in CrT mRNA levels.
            • Key findings · abstract:Cardiac creatine uptake levels in CrT-OE mice were increased on average 2.7-fold, showing a considerable variation, in line with a similar variation in creatine content.
            • Relative bioavailability · abstract:Hearts from GAMT(-/-) mice showed a 7-fold increase in V(max) of creatine uptake and a 1.4-fold increase in CrT mRNA levels.
            • Relative bioavailability · abstract:Cardiac creatine uptake levels in CrT-OE mice were increased on average 2.7-fold, showing a considerable variation, in line with a similar variation in creatine content.
            • Relative bioavailability · full text, Section 'Free energy change of creatine transport':Assuming a stoichiometry of 2:1 for Na+:Cr we calculated a reverse potential of 3 mV in WT hearts (74 nmol/mg protein creatine), and of − 26 mV in CrT-OE hearts with very high creatine levels (4-fold normal levels, i.e. 296 nmol/mg protein).
            • Food effect · full text, Section 'Mice':Mice were kept in cages with a 12 h light–dark cycle and controlled temperature (20–22 °C), fed creatine-free chow and water ad libitum.
            • Food effect · full text, Section 'Creatine uptake':Left ventricular creatine uptake in the presence of 1 mmol/L creatine amounted to 4.8 ± 0.6 and 5.6 ± 0.9 nmol/min/gww in hearts from creatine fed WT and creatine fed GAMT−/− mice (NS), respectively.
            • Food effect · full text, Section 'Creatine uptake':Right ventricular creatine uptake amounted to 4.5 ±0.4 and 5.3 ± 1.3 nmol/min/gww in creatine fed WT and creatine fed GAMT−/− hearts (NS), respectively.
            • Form comparison · full text, Section 'Creatine uptake':Right ventricular creatine uptake kinetics were similar to left ventricular uptake kinetics, but in GAMT−/−, right ventricular uptake was generally 10–15% lower (p < 0.05 vs GAMT−/− LV), as shown in Fig. 1B.
            • Form comparison · full text, Section 'Creatine levels':Left ventricular creatine levels were 74 ± 5 and 133 ± 43 nmol/mg protein in WT controls (n = 6) and CrT-OE mice (n = 9; p < 0.01 vs WT), respectively.
            • Form comparison · full text, Section 'Creatine levels':In both strains, right ventricular creatine levels tended to be lower (by about 7%) than left ventricular levels, a finding that was significant in WT controls (69 ± 7 nmol/mg protein; p < 0.01 vs LV) but not in CrT-OE (125 ± 46 nmol/mg protein;
          • RodentCreatine uptake in brain and skeletal muscle of mice lacking guanidinoacetate methyltransferase assessed by magnetic resonance spectroscopy.
            J Appl Physiol (1985), 2007 · Design: not stated · abstract only (PubMed) · closed/paywalled
            PMID 17347380DOI 10.1152/japplphysiol.01327.2006
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:After 35 days of Cr supplementation, Cr levels in all locations were higher compared with Con mice on a Cr-free diet and NAA levels normalized.
          • RodentIn vivo assessment of toxicity and pharmacokinetics of methylglyoxal. Augmentation of the curative effect of methylglyoxal on cancer-bearing mice by ascorbic acid and creatine.
            Toxicol Appl Pharmacol, 2006 · Design: not stated · abstract only (PubMed) · closed/paywalled
            PMID 16112157DOI 10.1016/j.taap.2005.07.003
            Verification: abstract-only auto-extract; unverified
            • RodentDevelopmental decrease in rat small intestinal creatine uptake.
              Mech Ageing Dev, 2005 · Design: not stated · abstract only (PubMed) · closed/paywalled
              PMID 15722111DOI 10.1016/j.mad.2004.11.005
              Verification: abstract-only auto-extract; unverified
              • Key findings · abstract:Herein the ontogeny and segmental distribution of rat intestinal creatine transport activity are investigated. [14C]-Creatine uptake was measured in the jejunum and ileum of 16 day gestation foetuses, newborn, suckling, weaning, 1-, 2-, 7- and 12-month-old (adult) rats.
              • Key findings · abstract:In 1-month-old rats, supplementation with creatine increased ileal, but not jejunal, creatine uptake.
            • RodentA creatine transporter is operative at the brush border level of the rat jejunal enterocyte.
              J Membr Biol, 2004 · Design: not stated · abstract only (PubMed) · closed/paywalled
              PMID 15702372DOI 10.1007/s00232-004-0721-8
              Verification: abstract-only auto-extract; unverified
              • Key findings · abstract:Moreover, creatine uptake is: 1) significantly inhibited by creatine structural analogs, 2) abolished by low concentrations of 2-aminoethyl methanethiosulfonate hydrobromide (MTSEA), 3) saturable as a function of creatine concentration with an apparent Michaelis-Menten constant of 24.08 +/- 0.80 muM and a maximal velocity of 391.30 +/- 6.19 pmoles mg protein(-1) 30 s(-1).
            • RodentCreatine uptake and creatine transporter expression among rat skeletal muscle fiber types.
              Am J Physiol Cell Physiol, 2003 · Design: not stated · abstract only (PubMed) · closed/paywalled
              PMID 12570986DOI 10.1152/ajpcell.00484.2002
              Verification: abstract-only auto-extract; unverified
              • Key findings · abstract:Creatine uptake rates at 1 mM creatine were greatest in the soleus (140 +/- 8.8 nmol x h(-1) x g(-1)), less in the red gastrocnemius (117 +/- 8.3), and least in the white gastrocnemius (97 +/- 10.7).
              • Key findings · abstract:Creatine uptake rates differ among skeletal muscle fiber sections in a manner reasonably assigned to the 58-kDa band of the CrT.
            • RodentThe effect of creatine supplementation on glucose uptake in rat skeletal muscle.
              Life Sci, 2002 · Design: not stated · abstract only (PubMed) · closed/paywalled
              PMID 12151051DOI 10.1016/s0024-3205(02)01941-0
              Verification: abstract-only auto-extract; unverified
              • Key findings · abstract:(3)H-2-deoxyglucose uptake was measured in epitrochlearis muscles incubated in the presence or absence of a maximally stimulating dose of insulin.
            • Rodent[Effect of creatine and other phosphorylable amino compounds on the ileal absorption of Ca-45 in the rat].
              C R Seances Acad Sci D, 1979 · Design: not stated · abstract only (PubMed) · unknown
              PMID 117913
              Verification: abstract-only auto-extract; unverified
              • RodentGrowth hormone effects on creatine uptake by muscle in the hypophysectomized rat.
                Mol Cell Biochem, 1979 · Design: not stated · abstract only (PubMed) · closed/paywalled
                PMID 460177DOI 10.1007/BF00228990
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:In contrast to minimal changes (20%) in liver methyltransferase, kidney transamidinase was decreased threefold in the hypophysectomized rat.
                • Key findings · abstract:The formation of creatine from radioactive precursors and the uptake of 14C-creatine in muscle was examined under these conditions.
              • Other animalCreatine uptake promotes dendritic cell activation and enhances antitumor immunity.
                iScience, 2026 · Design: not stated · abstract only (PubMed) · not checked (off-topic)
                PMID 42006288DOI 10.1016/j.isci.2026.115436PMC13091023 (free full text)
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:Slc6a8) in intratumoral DCs, which facilitates the cellular uptake of creatine, an energy-storage metabolite.
              • Other animalEffects of dietary guanidinoacetic acid on growth performance, guanidinoacetic acid absorption and creatine metabolism of lambs.
                PLoS One, 2022 · Design: not stated · full text (Europe PMC XML) + abstract · open access (gold)
                PMID 35275964DOI 10.1371/journal.pone.0264864PMC8916673 (free full text)PDF
                Verification: full-text auto-extracted verbatim snippets with location; needs human check
                • Key findings · abstract:With the increase of dietary GAA level, both Cr concentration in hepatic vein plasma and the portal plasma GAA concentration shows a quadratic change, with the highest concentration in the 500 mg/kg group and the lowest concentration in the 0 mg/kg group.
                • Food effect · abstract:The lambs were fed with the basal diets supplemented with 0 (0 mg/kg group), 500 (500 mg/kg group), 1000 (1000 mg/kg group) and 1500 mg (1500 mg/kg group) GAA per kg diet (DM basis), respectively.
                • Form comparison · full text, Section '3.4 Contents of Cr in hepatic vein, and ':After 4 h of the feeding, the mRNA expression levels of GAMT in GAA supplementation groups was increased compared with that in the 0 mg/kg group, but the values were similar (P>0.05) (Fig 1).
              • Other animalThe Dietary Supplement Creatyl-l-Leucine Does Not Bioaccumulate in Muscle, Brain or Plasma and Is Not a Significant Bioavailable Source of Creatine.
                Nutrients, 2022 · Design: not stated · full text (Europe PMC XML) + abstract · open access (gold)
                PMID 35277060DOI 10.3390/nu14030701PMC8840086 (free full text)
                Verification: full text read; no PK numbers matched
                • Other animalPharmacokinetics and hemorheology of phosphocreatine and creatine in rabbits: A directly comparative study between parent drug and active metabolite.
                  Eur J Pharm Sci, 2019 · Design: not stated · abstract only (PubMed) · closed/paywalled
                  PMID 31382031DOI 10.1016/j.ejps.2019.105033
                  Verification: abstract-only auto-extract; unverified
                  • Other animalCreatine uptake regulates CD8 T cell antitumor immunity.
                    J Exp Med, 2019 · Design: not stated · abstract only (PubMed) · not checked (off-topic)
                    PMID 31628186DOI 10.1084/jem.20182044PMC6888972 (free full text)
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:When studying nutrient usage of tumor-infiltrating immune cells in mice, we detected a sharp increase of the expression of a CrT (Slc6a8) gene, which encodes a surface transporter controlling the uptake of creatine into a cell.
                  • Other animalHypoxia decreases creatine uptake in cardiomyocytes, while creatine supplementation enhances HIF activation.
                    Physiol Rep, 2017 · Design: not stated · full text (Europe PMC XML) + abstract · open access (gold)
                    PMID 28821596DOI 10.14814/phy2.13382PMC5582266 (free full text)
                    Verification: full-text auto-extracted verbatim snippets with location; needs human check
                    • Form comparison · full text, Section 'Hypoxia reduces Cr transport in RNCM':Characterization of kinetics of Cr transport in transduced RNCMs subjected to hypoxia for 12 h revealed a significant decrease in V max (from 90.31 ± 7.07 to 30.76 ± 5.24 nmol/mg of protein) and K m (from 30.76 ± 5.24–7.20 ± 1.11 μmol/L) compared with controls (n = 3, t‐test P < 0.05).
                    • Form comparison · full text, Section 'Quantitation of ATP, Cr, and PCr':The cellular content of ATP, Cr, and PCr was measured in RNCM cultures exposed to 12 h of hypoxia in control media or media supplemented with Cr, AICAR, or both, and compared to similar cultures grown in the presence of oxygen (Fig. 5).
                    • Form comparison · full text, Section 'Quantitation of ATP, Cr, and PCr':Cr content was also quantified in cultures supplemented with Cr, AICAR, or both following 12 h of hypoxia and compared with RNCMs grown in similar conditions and control oxygen levels.
                  • Other animalApplication of NMR-based metabonomics suggests a relationship between betaine absorption and elevated creatine plasma concentrations in catheterised sows.
                    Br J Nutr, 2012 · Design: crossover · abstract (PubMed); full-text PDF saved · open access (bronze)
                    PMID 22673149DOI 10.1017/S0007114511004909PDF
                    Verification: full-text auto-extracted verbatim snippets with location; needs human check
                    • Key findings · abstract:The LF diet resulted in a higher betaine concentration in the blood than the two high-fibre diets (P=0·008).
                    • Key findings · abstract:This leads to higher plasma concentrations of methionine (P=0·0028) and creatine (P=0·020) of endogenous origin.
                    • Food effect · abstract:A total of six sows were fed a diet low in fibre (LF), a diet high in soluble fibre and a diet high in insoluble fibre in a repeated 3 × 3 cross-over design.
                    • Food effect · full text, p.2:ietary ingredients (g/kg diet) of the experimental diets quantitative uptake of glucose, lactate and SCFA and the apparent insulin production in sows fed a concentrated Diets LF HFS HFI control diet and two high-fibre diets (approximately 440 g Barley 420 145 145 DF/kg DM) composed of co-products from the vegetable Wheat 420 145 145 Sugarbeet pulp – 140 50 food and agro industries by using traditi
                    • Food effect · full text, p.3:ted by multiplying portal carried out as a 3 £ 3 repeated cross-over design with six flow measurements to the DAV according to absorption deter- sows fed the three different diets: LF, HFS and HFI, 7 d/diet. mination described by Rerat et al.(11). To exclude the water Non-pregnant sows with an initial average body weight of signal, the region 4·4– 5·0 ppm was not included in the statisti- 202 (SD
                    • Food effect · full text, p.5:mesenteric artery plasma samples, as illus- models. ANOVA is a univariate method that does not take trated in Fig. 1(A) and (B) for sampling of a HFI-fed pig 1 h covariance between the bins into account. However, a linear after feeding (see also Table 3). This demonstrates that differ- mixed model with PROC MIXED in the SAS statistical software ences in absorption can be seen from the DAV spectra
                    • Form comparison · full text, p.7:dissimilarities of feeding the different experimental diets. In Fig. 3, the mean CMV pre- 0 9 8 7 6 5 4 3 2 1 0 diction error based on twenty CMV is compared with 1000 Chemical shift (ppm) permutations under the H0 distribution for all venous samples Fig. 5. Rank product (RP1/20) from multilevel partial least-squares discrimi- and the DAV when the sows are fed the HFS or HFI diet at all nant analy
                    • Form comparison · full text, p.11:ption in the absorptive maybe caused by the higher dietary level of starch in the LF phase at 1 h after feeding, followed by a steady decline to diet compared with the two high-DF diets. This could have 4 and 10 h after feeding for all three diets. There was a diet negative effects when feeding the high-fibre diets. Because effect on concentration in plasma with the highest levels the high-fibre s
                  • Other animalThe creatine transporter mediates the uptake of creatine by brain tissue, but not the uptake of two creatine-derived compounds.
                    Neuroscience, 2006 · Design: not stated · abstract only (PubMed) · closed/paywalled
                    PMID 16949212DOI 10.1016/j.neuroscience.2006.06.058
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:We tested the double hypothesis that: (1) the creatine carrier is needed to make creatine cross the plasma membrane of brain cells and (2) creatine-derived molecules may cross this plasma membrane independently of the creatine carrier.
                  • Other animalJejunal creatine absorption: what is the role of the basolateral membrane?
                    J Membr Biol, 2005 · Design: not stated · abstract only (PubMed) · closed/paywalled
                    PMID 16550489DOI 10.1007/s00232-005-0813-0
                    Verification: abstract-only auto-extract; unverified
                    • Other animalMuscle creatine uptake and creatine transporter expression in response to creatine supplementation and depletion.
                      J Appl Physiol (1985), 2003 · Design: not stated · abstract only (PubMed) · closed/paywalled
                      PMID 12611762DOI 10.1152/japplphysiol.01171.2002
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:Cr uptake was assessed by skeletal muscle (14)C-Cr accumulation to Cr and PCr by using hindlimb perfusion, and CrT protein content was assessed by Western blot.
                      • Key findings · abstract:Cr uptake rate decreased with dietary Cr supplementation in the white gastrocnemius (WG; 45%) only.
                      • Key findings · abstract:Depletion of muscle Cr(total) to approximately 15% of normal increased Cr uptake in the soleus (21%) and red gastrocnemius (22%), corresponding to 70-150% increases in muscle CrT content.
                      • Key findings · abstract:In contrast, the inherently lower Cr uptake rate in the WG was unchanged with depletion of muscle Cr(total) even though CrT band density was incr[excerpt truncated in our database — see source]
                      • Food effect · abstract:To test this hypothesis, adult male Sprague-Dawley rats were fed 1% Cr, their muscle Cr(total) was reduced by approximately 85% [1% beta-guanidinoproprionic acid (beta-GPA)], or their muscle Cr(total) was repleted (1% Cr after beta-GPA depletion).
                    • Other animalComparison of ultrasonography and pharmacokinetic analysis of creatine kinase release for quantitative assessment of postinjection muscle damage in sheep.
                      Am J Vet Res, 2001 · Design: not stated · abstract only (PubMed) · not checked (off-topic)
                      PMID 11703010DOI 10.2460/ajvr.2001.62.1698
                      Verification: abstract-only auto-extract; unverified
                      • Other animalCreatine uptake in isolated soleus muscle: kinetics and dependence on sodium, but not on insulin.
                        Acta Physiol Scand, 1999 · Design: not stated · abstract only (PubMed) · closed/paywalled
                        PMID 10383488DOI 10.1046/j.1365-201x.1999.00539.x
                        Verification: abstract-only auto-extract; unverified
                        • Key findings · abstract:Consequently, we have investigated 14C-labelled creatine uptake in isolated, incubated rat soleus (type I) muscle preparations at 37 degrees C.
                        • Key findings · abstract:We found that the apparent Km for creatine uptake was 73 microM and the Vmax was 77 nmol h-1 gww-1.
                        • Key findings · abstract:Creatine uptake was 82% inhibited by 2 mM beta-guanidinopropionic acid, the structural analogue of creatine.
                        • Key findings · abstract:In addition, a decrease in buffer Na+ concentration, from 145 to 25 mM, reduced the rate of 14C-labelled creatine uptake by 77%, indicating that uptake is largely Na+-dependent in soleus muscle.
                        • Key findings · abstract:The total creatine content was 34% lower, bu[excerpt truncated in our database — see source]
                      • Other animal[Bioavailability of muscle creatine kinase in sheep. Application to the assessment of local tolerance to injectable veterinary formulations].
                        Vet Res, 1996 · Design: not stated · abstract only (PubMed) · not checked (off-topic)
                        PMID 8721293
                        Verification: abstract-only auto-extract; unverified
                        • Key findings · abstract:The change in the enzyme activity versus time in the plasma, after intravenous administration (123 +/- 38 U/kg) of creatine kinase, was fitted by a biexponential model.
                        • Key findings · abstract:The mean volume of the central compartment (45 +/- 5 mL/kg) was approximately equal to the plasma volume.
                        • Key findings · abstract:Plasma half-life and plasma clearance of creatine kinase were 3.7 +/- 1.7 h and 23 +/- 8 mL.kg-1.h-1, respectively.
                        • Key findings · abstract:Mean plasma bioavailability of creatine kinase after intramuscular administration (357 +/- 36 U/kg) in both the loins and the gluteal mass was 42%.
                        • Key findings · abstract:Maximal plasma activity was observed 4 and 5 h after[excerpt truncated in our database — see source]
                      • Other animalPharmacokinetic variables and bioavailability from muscle of creatine kinase in cattle.
                        Am J Vet Res, 1994 · Design: not stated · abstract only (PubMed) · not checked (off-topic)
                        PMID 8017694
                        Verification: abstract-only auto-extract; unverified
                        • Key findings · abstract:CK bioavailability after IM administration of the muscle extract; and effect of IM administration of saline solution, to appreciate the possible release of CK consecutive to muscle puncture, were determined in 6 cows.
                        • Key findings · abstract:Administration of saline solution IM had no effect on plasma CK activity (ANOVA, P > 0.05) in any of the cows.
                        • Key findings · abstract:After IV administration of the muscle extract (150 U/kg of body weight), mean volume of the central compartment, plasma half-life, and plasma clearance of CK were 0.027 +/- 0.007 L/kg, 520 +/- 109 minutes, and 6.43 +/- 2.29 ml/kg/h, respectively.
                        • Key findings · abstract:After IM administr[excerpt truncated in our database — see source]
                      • Other animalRelationship of intracellular creatine concentration and uptake to muscle mass in vivo.
                        Am J Physiol, 1978 · Design: not stated · abstract only (PubMed) · closed/paywalled
                        PMID 727242DOI 10.1152/ajpcell.1978.235.5.C199
                        Verification: abstract-only auto-extract; unverified
                        • Species unclearPopulation Pharmacokinetics of Phosphocreatine and Its Metabolite Creatine in Children With Myocarditis.
                          Front Pharmacol, 2020 · Design: not stated · full text (Europe PMC XML) + abstract · open access (gold)
                          PMID 33658923DOI 10.3389/fphar.2020.574141PMC7919190 (free full text)PDF
                          Verification: full text read; no PK numbers matched
                          • Key findings · abstract:Results: A total of 997 plasma concentrations (498 for PCr and 499 for Cr) were included in the analysis.
                        • Species unclearImpaired muscle uptake of creatine in spinal and bulbar muscular atrophy.
                          Ann Clin Transl Neurol, 2016 · Design: not stated · n: n = 65 · full text (Europe PMC XML) + abstract · open access (gold)
                          PMID 27386502DOI 10.1002/acn3.324PMC4931718 (free full text)
                          Verification: full text read; no PK numbers matched
                          • Key findings · abstract:METHODS: We evaluated blood chemistries, motor function, and muscle mass measured by dual-energy X-ray absorptiometry in male subjects with SBMA (n = 65), amyotrophic lateral sclerosis (ALS; n = 27), and healthy controls (n = 25).
                          • Key findings · abstract:RESULTS: Serum Cr concentrations were significantly lower in subjects with SBMA than in those with ALS (P < 0.001), despite similar muscle mass values.
                        • Species unclearPGC-1α and PGC-1β increase CrT expression and creatine uptake in myotubes via ERRα.
                          Biochim Biophys Acta, 2014 · Design: not stated · abstract only (PubMed) · open access (bronze)
                          PMID 25173818DOI 10.1016/j.bbamcr.2014.08.010
                          Verification: abstract-only auto-extract; unverified
                          • Key findings · abstract:We therefore hypothesized that PGC-1 and ERRα could also regulate CrT gene expression and creatine uptake in skeletal muscle.
                          • Key findings · abstract:Here we show that adenoviral overexpression of PGC-1α or PGC-1β in L6 myotubes increased CrT mRNA (2.1 and 1.7-fold, P<0.0125) and creatine uptake (1.8 and 1.6-fold, P<0.0125), and this effect was inhibited with co-expression of shRNA for ERRα.
                          • Key findings · abstract:Overexpression of a constitutively active ERRα (VP16-ERRα) increased CrT mRNA approximately 8-fold (P<0.05), resulting in a 2.2-fold (P<0.05) increase in creatine uptake.
                          • Relative bioavailability · abstract:Here we show that adenoviral overexpression of PGC-1α or PGC-1β in L6 myotubes increased CrT mRNA (2.1 and 1.7-fold, P<0.0125) and creatine uptake (1.8 and 1.6-fold, P<0.0125), and this effect was inhibited with co-expression of shRNA for ERRα.
                          • Relative bioavailability · abstract:Overexpression of a constitutively active ERRα (VP16-ERRα) increased CrT mRNA approximately 8-fold (P<0.05), resulting in a 2.2-fold (P<0.05) increase in creatine uptake.

                        Reviewer

                        Dr. Colin Reily, PhD

                        PhD, molecular pathology & biochemistry. Reviews the science and evidence (not medical advice).

                        Draft, pending sign-off Next review: set at sign-off

                        Animal and lab findings are labeled and never presented as proof of effects in people. Claims are limited to what the cited studies report. See our methodology.