Ashwagandha Absorption: Forms, Food & Timing, Compared
Bottom line
C: limited or conflicting human data: 1–2 studies, head-to-head and single-form evidence disagree, or baseline correction not reported. All grades are drafts pending reviewer sign-off.We found 15 studies with usable absorption data for this supplement, 3 of them in people; every value below is copied from its paper and cited.
Other standardized extract is the best-characterized form: 1 human study with measured absorption values (absorption evidence grade C).
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
- 15 (all full-text)
- Species
- 3 human, 10 rodent, 1 other animal, 1 in vitro
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.
Best-absorbed form
Draft — pending reviewer- No form clearly absorbs better: human head-to-head studies in our data do not separate the forms of ashwagandha.
- Most-studied form: Other standardized extract (1 human study with measured absorption, grade C). More data is not proof of better absorption.
- Caveat: without head-to-head studies, forms tested in separate studies can't be ranked fairly.
Absorption evidence only, from the graded comparisons on this page. Not a recommendation to buy any product, not dosing advice, not medical advice.
12 of 15 studies are not in humans; each is labeled with a species badge.
Ashwagandha forms compared
| Form | Studies (abstract screen) | Species |
|---|---|---|
| KSM-66 (root extract) | none yet | |
| Shoden (35% withanolide glycosides) | [PMID 42353009] | Human |
| Sensoril | none yet | |
| Zenroot | none yet | |
| Other standardized extract | [PMID 40792075][PMID 30904387][PMID 40352455][PMID 37481788][PMID 35268576][PMID 32890709] | HumanHumanRodentRodentRodentRodent |
Form tags are matched automatically and need reviewer confirmation. Values are not normalized across studies.
Species (abstract screen): 3 human, 4 rodent
7 studies (3 human) · show quotes
- Loading… Each study is also listed with its citation in Studies.
Ashwagandha shoden (35% withanolide glycosides) vs other standardized extract: 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.
Ashwagandha ksm-66 (root extract) vs other standardized extract: 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.
Should you take Ashwagandha with food?
B: 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 datahow we gradeSpecies (abstract screen): 2 human, 1 rodent
Grade basis (abstract screen): 2 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 studies (2 human) · show quotes
- Loading… Each study is also listed with its citation in Studies.
Best time to take Ashwagandha
Not graded: no comparable evidence yet. All grades are drafts pending reviewer sign-off.no datahow 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.
Ashwagandha cost per mg calculator
Compare what you pay per mg of each form. Shows published ranges only; no dose recommendations.
FAQ
Which form of Ashwagandha is best absorbed?
No form clearly absorbs better: human head-to-head studies in our data do not separate the forms of ashwagandha. Most-studied form: Other standardized extract (1 human study with measured absorption, grade C). More data is not proof of better absorption. Caveat: without head-to-head studies, forms tested in separate studies can't be ranked fairly. See the evidence →
Is Ashwagandha shoden (35% withanolide glycosides) better absorbed than other standardized extract?
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 the evidence →
Is Ashwagandha ksm-66 (root extract) better absorbed than other standardized extract?
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 the evidence →
Should Ashwagandha be taken with food?
We have 3 relevant studies in our database that mention food or fasting. See the evidence →
When is the best time to take Ashwagandha?
We have no relevant studies in our database that mention timing. See the evidence →
Is this dosing advice?
No. We summarize published absorption research and compare prices. Talk to a clinician about what's right for you. See the evidence →
Answers summarize the data on this page.
Measured absorption data (full-text extraction)
27 papers read in full text, 15 with usable data (12 excluded as off-topic, reviews or off-target). 179 values extracted. Species: Rodent 10Human 3Other animal 1In vitro 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
| Form | Studies | Values | Absorption evidence grade | Species |
|---|---|---|---|---|
| KSM-66 (root extract) | none yet | 0 | Not graded: no comparable evidence yet. All grades are drafts pending reviewer sign-off. no single-form human values | |
| Shoden (35% withanolide glycosides) | none yet | 0 | Not graded: no comparable evidence yet. All grades are drafts pending reviewer sign-off. no single-form human values | |
| Sensoril | none yet | 0 | Not graded: no comparable evidence yet. All grades are drafts pending reviewer sign-off. no single-form human values | |
| Zenroot | none yet | 0 | Not graded: no comparable evidence yet. All grades are drafts pending reviewer sign-off. no single-form human values | |
| Other standardized extract | 3 | 104 | C: limited or conflicting human data: 1–2 studies, head-to-head and single-form evidence disagree, or baseline correction not reported. All grades are drafts pending reviewer sign-off. 1 human study, total n=NR, 1 randomized/crossover; consistency not evaluable (no matched set with ≥2 studies) | Rodent×2Human×1 |
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 graded: no comparable evidence yet. All grades are drafts pending reviewer sign-off.Shoden (35% withanolide glycosides) vs Other standardized extractcombined head-to-head + matched single-form grade
no comparable evidence. H2H: none (no direct comparison in extracted data); indirect: none
Not graded: no comparable evidence yet. All grades are drafts pending reviewer sign-off.KSM-66 (root extract) vs Other standardized extractcombined 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 (178 values)
| Study | Arm / form | Dose | Fed | n | Analyte | Param | Value | Units | Source |
|---|---|---|---|---|---|---|---|---|---|
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | Tmax Tmax | 1.813 ± 0.063 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | Tmax Tmax | 2.219 ± 0.102 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | Tmax Tmax | 1.750 ± 0.065 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | Tmax Tmax | 2.219 ± 0.102 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | Tmax Tmax | 2.036 ± 0.036 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | Tmax Tmax | 1.964 ± 0.036 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | Tmax Tmax | ‡ | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | Tmax Tmax | 2.036 ± 0.036 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | Tmax Tmax | 2.200 ± 0.082 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | Tmax Tmax | 1.700 ± 0.065 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | Tmax Tmax | ‡ | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | Tmax Tmax | 1.733 ± 0.067 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 2.5% withanolides standardization, capsule | 7400 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | Tmax Tmax | 2.200 ± 0.082 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 2.5% withanolides standardization, capsule | 7400 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | Tmax Tmax | 1.500 ± 0.000 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 2.5% withanolides standardization, capsule | 7400 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | Tmax Tmax | 1.567 ± 0.067 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 2.5% withanolides standardization, capsule | 7400 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | Tmax Tmax | 1.500 ± 0.000 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | Cmax Cmax | 4.700 ± 0.225 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | Cmax Cmax | 49.050 ± 1.318 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | Cmax Cmax | 7.400 ± 0.423 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | Cmax Cmax | 60.419 ± 1.172 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | Cmax Cmax | 2.871 ± 0.071 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | Cmax Cmax | 2.786 ± 0.091 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | Cmax Cmax | ‡ | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | Cmax Cmax | 5.614 ± 0.147 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | Cmax Cmax | 2.560 ± 0.032 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | Cmax Cmax | 4.133 ± 0.142 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | Cmax Cmax | ‡ | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | Cmax Cmax | 6.340 ± 0.153 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 2.5% withanolides standardization, capsule | 7400 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | Cmax Cmax | 2.927 ± 0.059 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 2.5% withanolides standardization, capsule | 7400 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | Cmax Cmax | 5.860 ± 0.087 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 2.5% withanolides standardization, capsule | 7400 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | Cmax Cmax | 2.667 ± 0.040 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 2.5% withanolides standardization, capsule | 7400 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | Cmax Cmax | 10.780 ± 0.128 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | AUC AUC0-t | 28.377 ± 2.731 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | AUC AUC0-t | 580.230 ± 18.368 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | AUC AUC0-t | 38.361 ± 2.938 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | AUC AUC0-t | 656.521 ± 17.852 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | AUC AUC0-t | 10.552 ± 0.220 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | AUC AUC0-t | 10.336 ± 0.309 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | AUC AUC0-t | ‡ | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | AUC AUC0-t | 20.814 ± 0.478 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | AUC AUC0-t | 8.998 ± 0.193 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | AUC AUC0-t | 13.201 ± 0.299 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | AUC AUC0-t | ‡ | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | AUC AUC0-t | 22.382 ± 0.346 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 2.5% withanolides standardization, capsule | 7400 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | AUC AUC0-t | 10.663 ± 0.148 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 2.5% withanolides standardization, capsule | 7400 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | AUC AUC0-t | 19.726 ± 0.434 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 2.5% withanolides standardization, capsule | 7400 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | AUC AUC0-t | 6.986 ± 0.116 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 2.5% withanolides standardization, capsule | 7400 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | AUC AUC0-t | 37.790 ± 0.513 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | AUC AUC0-inf | 68.143 ± 15.107 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | AUC AUC0-inf | 737.755 ± 25.167 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | AUC AUC0-inf | 94.309 ± 13.358 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 35% withanolide glycosides standardization, capsule | 480 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | AUC AUC0-inf | 804.968 ± 23.409 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | AUC AUC0-inf | 16.570 ± 0.680 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | AUC AUC0-inf | 15.433 ± 0.586 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | AUC AUC0-inf | ‡ | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 10% withanolide glycosides standardization, capsule | 1800 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | AUC AUC0-inf | 30.917 ± 1.135 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanolide A (plasma) | AUC AUC0-inf | 14.921 ± 0.549 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withaferin A (plasma) | AUC AUC0-inf | 17.735 ± 0.439 (SEM) | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | withanoside IV (plasma) | AUC AUC0-inf | ‡ | NR | Table 1 |
| Human 40792075 | ashwagandha extract, 5% withanolides standardization, capsule | 3700 mg extract (NR) | fasted (minimum overnight fast of 10.00 hours) | NR | total withanolides (plasma) | AUC AUC0-inf | 29.286 ± 1.177 (SEM) | NR | Table 1 |
Showing 60 of 178 Cmax/Tmax/AUC values (human first). All 179 values are in /api/supplements/ashwagandha.
References for this section (1)
- Human Rathi P, Kim SK. Randomized, Double-Blind, Crossover Study Comparing the Bioavailability of 4 Ashwagandha (Withania somnifera (L.) Dunal) Extracts in Healthy Adults Under Fasting Condition. Current therapeutic research, clinical and experimental. 2025;103:100805. PMID 40792075. doi:10.1016/j.curtheres.2025.100805 PubMed · DOI · randomized crossover (double-blind, 4-treatment, 4-period, 4-sequence, single dose, 4-way), n=16
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
- KSM-66 (root extract) vs Other standardized extract: no human single-form arm with a printed value for KSM-66 (root extract)
- Shoden (35% withanolide glycosides) vs Other standardized extract: no human single-form arm with a printed value for Shoden (35% withanolide glycosides)
How this table was built
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.
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.
| Question | Grade & basis | Species |
|---|---|---|
| Page grade (best of the grades below) | C: limited or conflicting human data: 1–2 studies, head-to-head and single-form evidence disagree, or baseline correction not reported. All grades are drafts pending reviewer sign-off. | rubric v2, draft |
| Other standardized extract: absorption evidence | C: limited or conflicting human data: 1–2 studies, head-to-head and single-form evidence disagree, or baseline correction not reported. All grades are drafts pending reviewer sign-off. 1 human study, total n=NR, 1 randomized/crossover; consistency not evaluable (no matched set with ≥2 studies) | human |
| With food (abstract screen) | B: 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 datahow we grade 2 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. | 2 human, 1 rodent |
| Best time (abstract screen) | Not graded: no comparable evidence yet. All grades are drafts pending reviewer sign-off.no datahow we grade No relevant studies in the database for this question. | no studies |
Studies (15)
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 15 studies and quotes
- HumanWithanolides Are Detected in Human Urine Following Oral Administration of a Withania somnifera Product.International journal of molecular sciences, 2026 · Design: randomized crossover (described as single-center, randomized, double-blind crossover; only one participant completed both doses) · n: 4 · full text (PDF extraction) · open access: yesPMID 42353009DOI 10.3390/ijms27125289 (free full text)Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending4 verbatim quotes · view in JSON
- HumanRandomized, Double-Blind, Crossover Study Comparing the Bioavailability of 4 Ashwagandha (Withania somnifera (L.) Dunal) Extracts in Healthy Adults Under Fasting Condition.Current therapeutic research, clinical and experimental, 2025 · Design: randomized crossover (double-blind, 4-treatment, 4-period, 4-sequence, single dose, 4-way) · n: 16 · full text (PDF extraction) · open access: yesPMID 40792075DOI 10.1016/j.curtheres.2025.100805 (free full text)Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending6 verbatim quotes · view in JSON
- HumanSafety and pharmacokinetics of Withaferin-A in advanced stage high grade osteosarcoma: A phase I trial.Journal of Ayurveda and integrative medicine, 2020 · Design: open-label (single-center phase I 3+3 dose escalation) · n: 13 · full text (PDF extraction) · open access: yesPMID 30904387DOI 10.1016/j.jaim.2018.12.008 (free full text)Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending1 verbatim quote · view in JSON
- RodentFortified Withaferin A accelerates the transition from fibrovascular to bone remodeling phase during endochondral bone formation to promote ossification.Frontiers in endocrinology, 2025 · Design: single-arm · n: NR for PK · full text (PDF extraction) · open access: yesPMID 40352455DOI 10.3389/fendo.2025.1540237 (free full text)Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending3 verbatim quotes · view in JSON
- RodentSimultaneous estimation of five biomarkers of neuroprotective herb Ashwagandha NMITLI-118R AF1 in rat plasma and brain using LC-ESI-MS/MS: Application to its pharmacokinetic and stability studies.Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 2023 · Design: single-arm · n: NR (Abstract: eight groups of five rats; Methods: seven groups of six rats) · full text (PDF extraction) · open access: noPMID 37481788DOI 10.1016/j.jchromb.2023.123834Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending2 verbatim quotes · view in JSON
- RodentPharmacokinetic Study of Withanosides and Withanolides from Withania somnifera Using Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry (UHPLC-MS/MS).Molecules (Basel, Switzerland), 2022 · Design: single-arm · n: 18 animals · full text (PDF extraction) · open access: yesPMID 35268576DOI 10.3390/molecules27051476 (free full text)Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending1 verbatim quote · view in JSON
- RodentSafety, toxicity and pharmacokinetic assessment of oral Withaferin-A in mice.Toxicology reports, 2022 · Design: parallel · full text (PDF extraction) · open access: yesPMID 36518386DOI 10.1016/j.toxrep.2022.05.012 (free full text)Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending7 verbatim quotes · view in JSON
- RodentPharmacological and pharmacokinetic effect of a polyherbal combination with Withania somnifera (L.) Dunal for the management of anxiety.Journal of ethnopharmacology, 2021 · Design: single-arm (single-group animal PK) · n: 6 · full text (PDF extraction) · open access: noPMID 32890709DOI 10.1016/j.jep.2020.113337Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending5 verbatim quotes · view in JSON
- RodentPreparation and characterization of withaferin A loaded pegylated nanoliposomal formulation with high loading efficacy: In vitro and in vivo anti-tumour study.Materials science & engineering. C, Materials for biological applications, 2021 · Design: other (formulation characterisation, in vitro and in vivo biodistribution and anti-tumour study) · full text (PDF extraction) · open access: noPMID 34474886DOI 10.1016/j.msec.2021.112335Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending1 verbatim quote · view in JSON
- RodentStudies on oral bioavailability and first-pass metabolism of withaferin A in rats using LC-MS/MS and Q-TRAP.Biomedical chromatography : BMC, 2019 · Design: parallel (i.v. vs oral groups) plus in vitro assays · n: 15 male SD rats purchased (as stated); PK groups n = 6 each · full text (PDF extraction) · open access: noPMID 31062367DOI 10.1002/bmc.4573Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending5 verbatim quotes · view in JSON
- RodentLiquid chromatography-tandem mass spectrometry to assess the pharmacokinetics and tissue distribution of withaferin A in rats.Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 2019 · Design: parallel (dose groups) · full text (PDF extraction) · open access: noPMID 31173997DOI 10.1016/j.jchromb.2019.05.016Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending2 verbatim quotes · view in JSON
- RodentDetermination of permeability, plasma protein binding, blood partitioning, pharmacokinetics and tissue distribution of Withanolide A in rats: A neuroprotective steroidal lactone.Drug development research, 2018 · Design: parallel (i.v. group vs oral group; separate i.v. tissue distribution groups) plus in vitro assays · n: 12 rats for PK; 36 rats for tissue distribution · full text (PDF extraction) · open access: noPMID 30284738DOI 10.1002/ddr.21463Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending8 verbatim quotes · view in JSON
- RodentWithaferin A inhibits breast cancer invasion and metastasis at sub-cytotoxic doses by inducing vimentin disassembly and serine 56 phosphorylation.International journal of cancer, 2011 · Design: other (single-dose PK in mice, 3 mice/timepoint) · n: 30 mice · full text (PDF extraction) · open access: noPMID 21538350DOI 10.1002/ijc.25938Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending6 verbatim quotes · view in JSON
- Other animalComparisons of the pharmacokinetic and tissue distribution profiles of withanolide B after intragastric administration of the effective part of Datura metel L. in normal and psoriasis guinea pigs.Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 2018 · Design: other (parallel two-group single-dose animal PK and tissue distribution) · full text (PDF extraction) · open access: noPMID 29574380DOI 10.1016/j.jchromb.2018.02.022Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending10 verbatim quotes · view in JSON
- In vitroElucidation of plasma protein binding, blood partitioning, permeability, CYP phenotyping and CYP inhibition studies of Withanone using validated UPLC method: An active constituent of neuroprotective herb Ashwagandha.Journal of ethnopharmacology, 2021 · Design: other (in vitro) · full text (PDF extraction) · open access: noPMID 33460762DOI 10.1016/j.jep.2021.113819Verification: values extracted verbatim from the full-text PDF (bundle 2, 2026-11-02); reviewer check pending3 verbatim quotes · view in JSON
Reviewer
PhD, molecular pathology (UAB); BS, molecular biology & biochemistry (St. Olaf College). 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.