EvidenceCLimitedStudies in people with real weaknesses: small, short or conflicting trials, or observational studies only.
Yes, in most small trials ashwagandha lowered cortisol, the main stress hormone, more than a dummy pill did. Results vary a lot between trials, and one found no difference.
Who it's for
Stressed adults; not shown to help people without stress.
What to expect
Modestly lower cortisol after 8 to 12 weeks; size varies widely.
Watch out for
Long-term safety and effects on adrenal function are unknown.
Ashwagandha lowered cortisol across pooled trials
Each dot is a pooled result with a line showing its likely range; dots left of zero mean lower cortisol.
← BetterWorse →
No difference
Meta-analysis of 9 trials−2.58 (−4.99 to −0.16)Probably better
The NIH Office of Dietary Supplements says research suggests ashwagandha extracts may lower stress, anxiety and cortisol1Guideline · 2025Ashwagandha: Is it helpful for stress, anxiety, or sleep? Fact Sheet for Health ProfessionalsResearch suggests that ashwagandha extracts may lower stress, anxiety, and cortisol levels. A taskforce created by the World Federation of Societies of Biological Psychiatry and the Canadian Network for Mood and Anxiety Treatments provisionally recommends specific daily doses of ashwagandha root extract for the trea…NIH Office of Dietary Supplements. An international taskforce provisionally recommends 300 to 600 mg a day of root extract for generalized anxiety disorder, and says it can't be firmer without more data1Guideline · 2025Ashwagandha: Is it helpful for stress, anxiety, or sleep? Fact Sheet for Health ProfessionalsResearch suggests that ashwagandha extracts may lower stress, anxiety, and cortisol levels. A taskforce created by the World Federation of Societies of Biological Psychiatry and the Canadian Network for Mood and Anxiety Treatments provisionally recommends specific daily doses of ashwagandha root extract for the trea…NIH Office of Dietary Supplements.
What the studies show
A review that pooled 23 randomized trials People are assigned by chance to the treatment or a comparison, so a difference in results is likely caused by the treatment itself. (1,706 adults) found a large drop in cortisol compared with a dummy pill (placebo A dummy treatment that looks like the real one, so people can't tell which they got.). Results differed widely between trials, and the dose-response findings were only suggestive10Meta-analysis · 2026 · 1,706 peopleHormonal Modulation with Withania somnifera: Systematic Review and Meta-Analysis of Randomized-controlled Trials.Ashwagandha supplementation appears to modulate key hormonal pathways, particularly cortisol and sex hormones. However, heterogeneity and limited data on some endpoints warrant further standardized trials.Planta Med.
A review that pooled 9 trials (558 people) found lower blood cortisol than placebo. The true effect could be anything from almost none to a clear drop8Meta-analysis · 2024 · 558 peopleEffects of Ashwagandha (Withania Somnifera) on stress and anxiety: A systematic review and meta-analysis.The findings from the included studies indicate that Ashwagandha formulations have beneficial effects on stress and anxiety. The adverse effects associated with Ashwagandha are limited; however, further information is required to determine its safety with long-term administration.Explore (NY).
A systematic review A review that searches for every study on a question in a set way and weighs them together, rather than picking a few. of 9 trials in stressed people, lasting 30 to 112 days, concluded ashwagandha decreased cortisol. The trials differed in design, extract and dose5Systematic review · 2023Effects of Withania somnifera on Cortisol Levels in Stressed Human Subjects: A Systematic Review.Brief-term supplementation with WS appears to have a stress-reducing effect in stressed individuals. However, since the long-term effects of WS supplementation are not yet fully understood, WS supplements should be used under medical supervision.Nutrients.
A 60-day trial of 60 stressed adults, using 240 mg daily, found a greater fall in morning cortisol than placebo2Randomized trial · 2019An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract: A randomized, double-blind, placebo-controlled study.These findings suggest that ashwagandha's stress-relieving effects may occur via its moderating effect on the hypothalamus-pituitary-adrenal axis. However, further investigation utilizing larger sample sizes, diverse clinical and cultural populations, and varying treatment dosages are needed to substantiate these…Medicine (Baltimore). A trial of 54 adults using 500 mg of extract for 60 days found the same in morning saliva cortisol3Randomized trial · 2023 · 54 peopleA 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.The results of the study suggest that ARE with 2.5% withanolides can effectively improve stress and anxiety by reducing cortisol and increasing serotonin in healthy individuals with mild to moderate symptoms.Medicine (Baltimore).
A trial of 57 overweight men aged 40 to 70 found no clear difference in cortisol after 8 weeks, though testosterone and DHEA-S (another adrenal hormone) rose more than with placebo7Randomized trial · 2019 · 50 peopleA Randomized, Double-Blind, Placebo-Controlled, Crossover Study Examining the Hormonal and Vitality Effects of Ashwagandha ( Withania somnifera) in Aging, Overweight Males.In conclusion, the intake of a standardized ashwagandha extract (Shoden beads) for 8 weeks was associated with increased levels of DHEA-S and testosterone, although no significant between-group differences were found in cortisol, estradiol, fatigue, vigor, or sexual well-being. Further studies with larger sample sizes…Am J Mens Health.
These figures compare groups, so the gain for one person depends on their starting cortisol and stress level. Most trials were small, short and measured cortisol as a secondary outcome.
Key studies
Study
Who
What it found
Review of 23 trials, 202610Meta-analysis · 2026 · 1,706 peopleHormonal Modulation with Withania somnifera: Systematic Review and Meta-Analysis of Randomized-controlled Trials.Ashwagandha supplementation appears to modulate key hormonal pathways, particularly cortisol and sex hormones. However, heterogeneity and limited data on some endpoints warrant further standardized trials.Planta Med
1,706 adults
Large cortisol drop versus placebo; wide variation
Review of 9 trials, 20248Meta-analysis · 2024 · 558 peopleEffects of Ashwagandha (Withania Somnifera) on stress and anxiety: A systematic review and meta-analysis.The findings from the included studies indicate that Ashwagandha formulations have beneficial effects on stress and anxiety. The adverse effects associated with Ashwagandha are limited; however, further information is required to determine its safety with long-term administration.Explore (NY)
558 people
Lower blood cortisol than placebo
Trial, 20192Randomized trial · 2019An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract: A randomized, double-blind, placebo-controlled study.These findings suggest that ashwagandha's stress-relieving effects may occur via its moderating effect on the hypothalamus-pituitary-adrenal axis. However, further investigation utilizing larger sample sizes, diverse clinical and cultural populations, and varying treatment dosages are needed to substantiate these…Medicine (Baltimore)
60 stressed adults
Morning cortisol fell more than placebo
Trial, 20233Randomized trial · 2023 · 54 peopleA 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.The results of the study suggest that ARE with 2.5% withanolides can effectively improve stress and anxiety by reducing cortisol and increasing serotonin in healthy individuals with mild to moderate symptoms.Medicine (Baltimore)
54 adults, mild to moderate stress
Morning saliva cortisol fell more than placebo
Trial, 20197Randomized trial · 2019 · 50 peopleA Randomized, Double-Blind, Placebo-Controlled, Crossover Study Examining the Hormonal and Vitality Effects of Ashwagandha ( Withania somnifera) in Aging, Overweight Males.In conclusion, the intake of a standardized ashwagandha extract (Shoden beads) for 8 weeks was associated with increased levels of DHEA-S and testosterone, although no significant between-group differences were found in cortisol, estradiol, fatigue, vigor, or sexual well-being. Further studies with larger sample sizes…Am J Mens Health
57 overweight men, 40 to 70
No clear cortisol difference from placebo
Safety
No serious side effects were reported in the reviews of healthy or stressed adults5Systematic review · 2023Effects of Withania somnifera on Cortisol Levels in Stressed Human Subjects: A Systematic Review.Brief-term supplementation with WS appears to have a stress-reducing effect in stressed individuals. However, since the long-term effects of WS supplementation are not yet fully understood, WS supplements should be used under medical supervision.Nutrients,9Systematic review · 2023Effects of Withania somnifera (Ashwagandha) on Hematological and Biochemical Markers, Hormonal Behavior, and Oxidant Response in Healthy Adults: A Systematic Review.Ws supplementation appears to be safe, may regulate hormone levels, and has potent anti-inflammatory and antioxidant effects. However, further studies are needed to elucidate the relevance of its application.Curr Nutr Rep. In one review, four of nine trials reported mild to moderate side effects8Meta-analysis · 2024 · 558 peopleEffects of Ashwagandha (Withania Somnifera) on stress and anxiety: A systematic review and meta-analysis.The findings from the included studies indicate that Ashwagandha formulations have beneficial effects on stress and anxiety. The adverse effects associated with Ashwagandha are limited; however, further information is required to determine its safety with long-term administration.Explore (NY). Long-term safety and the effect of lower cortisol on adrenal function haven't been studied, and one review advises medical supervision5Systematic review · 2023Effects of Withania somnifera on Cortisol Levels in Stressed Human Subjects: A Systematic Review.Brief-term supplementation with WS appears to have a stress-reducing effect in stressed individuals. However, since the long-term effects of WS supplementation are not yet fully understood, WS supplements should be used under medical supervision.Nutrients.
What we don't know
Whether lower cortisol is what makes people feel less stressed, and whether the drop lasts beyond about 4 months.
Which dose and extract work best. Trials used different products, from 125 to 500 mg of extract a day3Randomized trial · 2023 · 54 peopleA 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.The results of the study suggest that ARE with 2.5% withanolides can effectively improve stress and anxiety by reducing cortisol and increasing serotonin in healthy individuals with mild to moderate symptoms.Medicine (Baltimore),6Randomized trial · 2024 · 131 peopleEffects of Withania somnifera Extract in Chronically Stressed Adults: A Randomized Controlled Trial.Our findings demonstrate the stress-reduction capabilities of this well-characterized aqueous extract of WS (root and leaf) at the low dose of 125 mg/day, in a dose-dependent manner, via the modulation of the HPA axis.Nutrients.
Written by AI from the studies listed, without review by a clinician, and graded with the GRADE method. It can be wrong, so check the studies it cites. Education, not medical advice.