Also known as Withania somnifera
Adaptogenic root herb whose withanolide compounds are thought to blunt HPA-axis cortisol release; clinical trials link standardised extracts to reduced perceived stress and anxiety scores.
Reported side effects:Loose stoolsNauseaDrowsiness
Be careful if: pregnant, breastfeeding, some medical situations
Suspect a side effect? Report it to the MHRA Yellow Card scheme ↗
We link to relevant studies and leave interpretation to you and your healthcare professional.
The large figures are what the studies reported for each thing they measured. Open a card for every result.
Colour keyReported a benefitNo clear benefitUnclearPossible harmAmber is for highlights, such as where the most research is. It never means a result was good.
Also measured alongside: Stress levels (reported a benefit); Overall sleep (reported a benefit); Quality of life (mixed results); and 7 more.
Every resultAlso measured alongside: Fatigue symptoms (reported a benefit); Overall well-being (reported a benefit); Free testosterone (reported a benefit); and 2 more.
Every resultWhat sources report about side effects, who should be careful, and medicines to ask about first.
| Reported effect | How often | Basis | Sources |
|---|---|---|---|
| Loose stools | common | Listed by NIH ODS fact sheets | Ashwagandha (NIH ODS fact sheet, Health Professional edition; retrieved via Internet Archive snapshot 2026-10-07) |
| Nausea | common | Listed by NIH ODS fact sheets | Ashwagandha (NIH ODS fact sheet, Health Professional edition; retrieved via Internet Archive snapshot 2026-10-07) |
| Drowsiness | common | Listed by NIH ODS fact sheets | Ashwagandha (NIH ODS fact sheet, Health Professional edition; retrieved via Internet Archive snapshot 2026-10-07) |
| Reported effect | How often | Basis | Sources |
|---|---|---|---|
| Adverse effects on liver function (a few reports) | unknown | Listed by NIH ODS fact sheets | Ashwagandha (NIH ODS fact sheet, Health Professional edition; retrieved via Internet Archive snapshot 2026-10-07) |
| Applies to | What sources say | Sources |
|---|---|---|
| pregnant | Some experts advise against the use of ashwagandha by women who are pregnant (NIH ODS). | Ashwagandha (NIH ODS fact sheet, Health Professional edition; retrieved via Internet Archive snapshot 2026-10-07) |
| breastfeeding | No breastfeeding-specific guidance found in the sources checked (NIH ODS ashwagandha fact sheet has no lactation statement); NIH ODS notes only that long-term use has not been studied. | Ashwagandha (NIH ODS fact sheet, Health Professional edition; retrieved via Internet Archive snapshot 2026-10-07) |
| some medical situations | Some experts advise against use by men with hormone-sensitive prostate cancer (NIH ODS). | Ashwagandha (NIH ODS fact sheet, Health Professional edition; retrieved via Internet Archive snapshot 2026-10-07) |
| some medical situations | Ashwagandha might affect thyroid function and interact with some medicines; people with thyroid conditions or on regular medication should ask a clinician before use (NIH ODS). | Ashwagandha (NIH ODS fact sheet, Health Professional edition; retrieved via Internet Archive snapshot 2026-10-07) |
Audited published research for Ashwagandha by condition. Drill into a pair page for the full breakdown.
What this means: Bars count reported findings, not treatment effectiveness or certainty.
One study may report several findings or appear in more than one pairing. Counts do not show the size of an effect. Comparable numerical estimates are not established for this summary.
| Compound and condition | Findings (count) | Studies (count) | Reported results (finding counts) | How sure? |
|---|---|---|---|---|
| Anxiety | 15 | 3 | Benefit: 11; no benefit: 4; harm: 0; unclear: 0; not recorded / unrecognised: 0 | Not formally graded |
| Stress | 6 | 2 | Benefit: 5; no benefit: 1; harm: 0; unclear: 0; not recorded / unrecognised: 0 | Not formally graded |
Where people report using it and what trials suggest
Common claims the trials do not support
Adaptogenic herb (Withania somnifera) with multiple small RCTs showing reduced perceived stress and cortisol; trial quality is variable and long-term safety data limited.
Evidence grades reflect study quality and consistency, not marketing claims.
Ordered by strength of evidence, then result direction.
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5 of 22 referenced studies are marked supplier-affiliated in the corpus.
Reported results grouped by condition. Values and units are preserved as recorded; missing information is not estimated.
How to read this table
Reported direction, numerical results and study design are separate. Certainty has not been formally graded in this table.
| What was measured | Reported findings | Result and units | Reported sample and duration | Study / source |
|---|---|---|---|---|
| anxiety | Anxiety scores improved with SMD -1.55 vs placebo in 1,002 people. (95% CI: -2.37, -0.74; p = .005; I2 = 93.8%)Benefit seen | -1.55 SMD Recorded unit: Not reported | Sample (as reported): 1,002 Follow-up: Not reported | Meta-analysis · 2022 Study detailsDoes Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of randomized controlled trials. Meta-Analysis |
| stress level | Stress levels improved with SMD -1.75 vs placebo in 1,002 people. (95% CI: -2.29, -1.22; p = .005; I2 = 83.1%)Benefit seen | -1.75 SMD Recorded unit: Not reported | Sample (as reported): 1,002 Follow-up: Not reported | Meta-analysis · 2022 Study detailsDoes Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of randomized controlled trials. Meta-Analysis |
| anxiety level | Ashwagandha improved anxiety levels versus placebo in 400 participants, though no specific effect size was reported.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 400 Follow-up: Not reported | Meta-analysis · 2021 Study detailsEffect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysis. Meta-Analysis |
| mental alertness on rising | Ashwagandha improved mental alertness on rising versus placebo in 400 participants, though no specific effect size was reported.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 400 Follow-up: Not reported | Meta-analysis · 2021 Study detailsEffect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysis. Meta-Analysis |
| overall sleep | Ashwagandha improved overall sleep with a standardized mean difference of -0.59 versus placebo in 400 participants. (95% Confidence Interval -0.75 to -0.42)Benefit seen | -0.59 Standardized Mean Difference Recorded unit: Not reported | Sample (as reported): 400 Follow-up: Not reported | Meta-analysis · 2021 Study detailsEffect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysis. Meta-Analysis |
| quality of life | Ashwagandha showed no significant effect on quality of life versus placebo in 400 participants.No clear benefit | Not reported Recorded unit: Not reported | Sample (as reported): 400 Follow-up: Not reported | Meta-analysis · 2021 Study detailsEffect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysis. Meta-Analysis |
| CANTAB multitasking, concentration, and decision taking time | Cognitive scores improved significantly vs placebo in 50 people over 60 days.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 50 Follow-up: 60 days | Randomised trial · 2023 Study detailsA standardized Ashwagandha root extract alleviates stress, anxiety, and improves quality of life in healthy adults by modulating stress hormones: Results from a randomized, double-blind, placebo-controlled study. Randomized Controlled Trial |
| Generalized Anxiety Disorder (GAD-7) | Anxiety scores improved significantly vs placebo in 50 people over 60 days.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 50 Follow-up: 60 days | Randomised trial · 2023 Study detailsA standardized Ashwagandha root extract alleviates stress, anxiety, and improves quality of life in healthy adults by modulating stress hormones: Results from a randomized, double-blind, placebo-controlled study. Randomized Controlled Trial |
| Morning salivary cortisol | Cortisol levels reduced significantly vs placebo in 50 people over 60 days.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 50 Follow-up: 60 days | Randomised trial · 2023 Study detailsA standardized Ashwagandha root extract alleviates stress, anxiety, and improves quality of life in healthy adults by modulating stress hormones: Results from a randomized, double-blind, placebo-controlled study. Randomized Controlled Trial |
| Perceived Stress Scale (PSS) | Stress scores improved significantly vs placebo in 50 people over 60 days.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 50 Follow-up: 60 days | Randomised trial · 2023 Study detailsA standardized Ashwagandha root extract alleviates stress, anxiety, and improves quality of life in healthy adults by modulating stress hormones: Results from a randomized, double-blind, placebo-controlled study. Randomized Controlled Trial |
| Quality of Life (QOL) | Quality of life scores improved significantly vs placebo in 50 people over 60 days.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 50 Follow-up: 60 days | Randomised trial · 2023 Study detailsA standardized Ashwagandha root extract alleviates stress, anxiety, and improves quality of life in healthy adults by modulating stress hormones: Results from a randomized, double-blind, placebo-controlled study. Randomized Controlled Trial |
| Serum glutathione (GSH) | No significant difference in glutathione vs placebo in 50 people over 60 days.No clear benefit | Not reported Recorded unit: Not reported | Sample (as reported): 50 Follow-up: 60 days | Randomised trial · 2023 Study detailsA standardized Ashwagandha root extract alleviates stress, anxiety, and improves quality of life in healthy adults by modulating stress hormones: Results from a randomized, double-blind, placebo-controlled study. Randomized Controlled Trial |
| Serum malondialdehyde (MDA) | No significant difference in malondialdehyde vs placebo in 50 people over 60 days.No clear benefit | Not reported Recorded unit: Not reported | Sample (as reported): 50 Follow-up: 60 days | Randomised trial · 2023 Study detailsA standardized Ashwagandha root extract alleviates stress, anxiety, and improves quality of life in healthy adults by modulating stress hormones: Results from a randomized, double-blind, placebo-controlled study. Randomized Controlled Trial |
| Serum nitric oxide (NO) | No significant difference in nitric oxide vs placebo in 50 people over 60 days.No clear benefit | Not reported Recorded unit: Not reported | Sample (as reported): 50 Follow-up: 60 days | Randomised trial · 2023 Study detailsA standardized Ashwagandha root extract alleviates stress, anxiety, and improves quality of life in healthy adults by modulating stress hormones: Results from a randomized, double-blind, placebo-controlled study. Randomized Controlled Trial |
| Urinary serotonin | Serotonin levels increased significantly vs placebo in 50 people over 60 days.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 50 Follow-up: 60 days | Randomised trial · 2023 Study detailsA standardized Ashwagandha root extract alleviates stress, anxiety, and improves quality of life in healthy adults by modulating stress hormones: Results from a randomized, double-blind, placebo-controlled study. Randomized Controlled Trial |
| What was measured | Reported findings | Result and units | Reported sample and duration | Study / source |
|---|---|---|---|---|
| Chalder Fatigue Scale | Ashwagandha significantly reduced fatigue symptoms compared to placebo in adults over 12 weeks. (p=0.016)Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): Not reported Follow-up: 12-week | Randomised trial · 2023 Study detailsExploring the efficacy and safety of a novel standardized ashwagandha (Withania somnifera) root extract (Witholytin®) in adults experiencing high stress and fatigue in a randomized, double-blind, placebo-controlled trial. Randomized Controlled Trial |
| Free testosterone | Ashwagandha significantly increased free testosterone in men compared to placebo over 12 weeks. (p=0.048)Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): Not reported Follow-up: 12-week | Randomised trial · 2023 Study detailsExploring the efficacy and safety of a novel standardized ashwagandha (Withania somnifera) root extract (Witholytin®) in adults experiencing high stress and fatigue in a randomized, double-blind, placebo-controlled trial. Randomized Controlled Trial |
| Heart rate variability | Ashwagandha significantly increased heart rate variability compared to placebo in adults over 12 weeks. (p=0.003)Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): Not reported Follow-up: 12-week | Randomised trial · 2023 Study detailsExploring the efficacy and safety of a novel standardized ashwagandha (Withania somnifera) root extract (Witholytin®) in adults experiencing high stress and fatigue in a randomized, double-blind, placebo-controlled trial. Randomized Controlled Trial |
| Luteinizing hormone | Ashwagandha significantly increased luteinizing hormone in men compared to placebo over 12 weeks. (p=0.002)Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): Not reported Follow-up: 12-week | Randomised trial · 2023 Study detailsExploring the efficacy and safety of a novel standardized ashwagandha (Withania somnifera) root extract (Witholytin®) in adults experiencing high stress and fatigue in a randomized, double-blind, placebo-controlled trial. Randomized Controlled Trial |
| Perceived Stress Scale | Ashwagandha did not significantly reduce stress levels compared to placebo in adults over 12 weeks. (p=0.867)No clear benefit | Not reported Recorded unit: Not reported | Sample (as reported): Not reported Follow-up: 12-week | Randomised trial · 2023 Study detailsExploring the efficacy and safety of a novel standardized ashwagandha (Withania somnifera) root extract (Witholytin®) in adults experiencing high stress and fatigue in a randomized, double-blind, placebo-controlled trial. Randomized Controlled Trial |
| perceived well-being (energy, mental clarity, sleep quality, stress) | Ashwagandha improved perceived well-being vs placebo in 60 college students over 30 days.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 60 Follow-up: 30 days | Randomised trial · 2022 Study detailsThe Perceived Impact of Ashwagandha on Stress, Sleep Quality, Energy, and Mental Clarity for College Students: Qualitative Analysis of a Double-Blind Randomized Control Trial. Randomized Controlled Trial |
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