The short version
- Pooling 23 randomised placebo-controlled trials in 1,706 people, ashwagandha raised testosterone in men by a mean 57.43 ng/dL but not in women, where the difference was 5.09 ng/dL.
- The cortisol case is the better-supported half: a 2025 meta-analysis of seven trials found cortisol fell by 1.16 µg/dL while pooled Perceived Stress Scale scores did not significantly change.
- In a 16-week crossover in overweight men aged 40 to 70, testosterone rose 14.7% and DHEA-S 18% versus placebo, yet fatigue, vigour and well-being showed no significant between-group difference.
- The most-cited strength trial ran eight weeks in 57 untrained men, where the placebo group still added 26.4kg to their bench press, so much of that result is untrained men starting to lift.
- The pooled analysis found a modest T4 increase of 0.61 µg/dL, so anyone with a diagnosed thyroid condition or taking thyroid medication should speak to a doctor first.
"Does ashwagandha actually do anything for a man, or is it just the stress herb my wife takes?" We get some version of that question most weeks, and it deserves a real answer rather than a product page. The short version: the men-specific data is more interesting than the general data, and it is also smaller and messier than the way it gets sold.
We have written elsewhere about why the dose on the label matters more than the brand on the front. This is a different question. Not how much — what it does in men specifically.
The sex difference is real, and it is recent
A systematic review and meta-analysis in Planta Medica pooled 23 randomised placebo-controlled trials covering 1,706 participants. Ashwagandha significantly reduced cortisol (standardised mean difference −1.18) and increased testosterone in men, by a mean difference of 57.43 ng/dL, but not in women, where the difference was 5.09 ng/dL — a statistically significant gap between the sexes. The authors also flag heterogeneity across trials and limited data on several endpoints, which is the correct disclaimer, so we are repeating it rather than dropping it.
57 ng/dL is a real finding and it is not a large one. Adult male total testosterone spans a wide reference range, and a mean difference that size will matter to some men and be invisible to others. Anyone selling ashwagandha as a testosterone product is quoting the direction of that result while quietly leaving out the magnitude.
The training trial everyone cites
Wankhede and colleagues, 2015, in the Journal of the International Society of Sports Nutrition: 57 men aged 18–50 with little resistance training experience, randomised to 300mg of ashwagandha root extract twice daily or a starch placebo, with both groups training for eight weeks.
The supplemented group gained more on the bench press (46.0kg versus 26.4kg, p = 0.001) and the leg extension (14.5kg versus 9.8kg, p = 0.04), added more arm and chest size, lost more body fat (3.5% versus 1.5%, p = 0.03), showed better stabilisation of creatine kinase after training, and had a larger testosterone increase — 96.2 ng/dL against 18.0 ng/dL in placebo, p = 0.004.
Now the honest reading. These were novices. The placebo group added 26.4kg to their bench in eight weeks, which tells you how much of the total effect here is simply "untrained men started lifting." One site, 57 men, eight weeks. It is a good result in the population most likely to produce a good result, and it has not been repeated at scale in trained men.
The trial where the hormones moved and the men did not notice
This is the one we think matters most, and it is the one nobody quotes. Lopresti and colleagues, 2019, in American Journal of Men's Health: a 16-week randomised, double-blind, placebo-controlled crossover in overweight men aged 40–70 with mild fatigue, using a concentrated extract delivering 21mg of withanolide glycosides a day for eight weeks. Fifty-seven enrolled; 43 completed all 16 weeks.
Ashwagandha was associated with an 18% greater increase in DHEA-S (p = .005) and a 14.7% greater increase in testosterone (p = .010) compared with placebo. And then: no statistically significant between-group differences in fatigue, vigour, or sexual and psychological well-being. No significant differences in cortisol or estradiol either.
Two hormones moved. How the men actually felt did not separate from placebo. If you are buying ashwagandha in order to feel different, that is the trial to sit with for a minute.
Cortisol: the better-supported claim, with its own hole in it
A 2025 systematic review and meta-analysis in Nutrition and Health pooled seven cortisol trials and six perceived-stress trials across 488 participants, at oral doses of at least 250mg a day for at least two weeks. Cortisol fell significantly — a reduction of 1.16 µg/dL, 95% CI −1.64 to −0.69, p < 0.001. Perceived Stress Scale scores did not: SMD −0.355, 95% CI −1.188 to 0.47, p = 0.40. Heterogeneity was moderate at I² = 50.9%, and the authors call the disconnect out themselves.
Individual trials — including the 60-day study most often printed on ashwagandha labels — have reported reductions in stress and anxiety scores. What this particular pooled analysis says is that across the trials measuring both, the biomarker moved reliably and the questionnaire did not. That is a real gap between "your cortisol came down" and "you feel less stressed," and we would rather hand it to you now than have you meet it on your own in week six.
The caveat we'd rather you heard from us
Ashwagandha interacts with thyroid physiology. The Planta Medica meta-analysis found no effect on TSH or T3, but a modest increase in T4 of 0.61 µg/dL (p = 0.02). If you have a diagnosed thyroid condition or take thyroid medication, this belongs in a conversation with your doctor before it belongs in your cupboard. Separately: almost every trial above ran eight to sixteen weeks. Nobody has good multi-year human data on continuous use, and we are not going to pretend that silence is reassurance.
What we'd actually tell you
If your training is going well and your stress load is manageable, ashwagandha probably has little to offer you. The trials producing the biggest numbers are in men who were untrained, overweight, fatigued or stressed at baseline — the further you sit from that starting point, the less room there is to move.
If you are training hard through a genuinely stressful stretch, the cortisol and training-stress case is where the evidence actually sits, and that is what we would buy it for. If you are buying it as a testosterone product, you are paying for the smallest and least consistent part of its file.
On dose: the numbers above came from 300mg of a standardised root extract twice daily, or a concentrated extract at an equivalent withanolide load. Read the withanolide percentage, not the milligram figure on the front of the bottle. Those are not the same claim.
Good questions
Does ashwagandha raise testosterone in men?
Modestly, and only in men. A meta-analysis of 23 trials in 1,706 people found a mean increase of 57.43 ng/dL in men against 5.09 ng/dL in women, a statistically significant sex difference. Adult male total testosterone spans a wide reference range, so a difference that size will matter to some men and be invisible to others. Anyone selling the direction of that result without the magnitude is being selective.
Will I actually feel different on ashwagandha?
Possibly not, and this is the trial nobody quotes. Over 16 weeks in overweight men aged 40 to 70 with mild fatigue, testosterone rose 14.7% and DHEA-S 18% versus placebo, and there were no significant between-group differences in fatigue, vigour, or sexual and psychological well-being. Two hormones moved; how the men felt did not separate from placebo. Sit with that before you buy.
Does ashwagandha lower stress or just lower cortisol?
The biomarker moves more reliably than the questionnaire. A 2025 meta-analysis across 488 participants found cortisol fell 1.16 µg/dL, while pooled Perceived Stress Scale scores did not change significantly. Individual trials have reported reductions in stress and anxiety scores, but across the trials measuring both, that gap is real. We would rather hand it to you now than have you meet it alone in week six.
Can I take ashwagandha if I have a thyroid condition?
Ask your doctor before you buy it. The pooled meta-analysis found no effect on TSH or T3 but a modest increase in T4 of 0.61 µg/dL. If you have a diagnosed thyroid condition or take thyroid medication, that belongs in a conversation with the person managing it rather than in your cupboard on the strength of a product page.
How much ashwagandha should I take, and does the brand matter?
The numbers above came from 300mg of a standardised root extract twice daily, or a concentrated extract delivering an equivalent withanolide load. Read the withanolide percentage rather than the milligram figure on the front of the bottle, because those are not the same claim. A large milligram number of weakly standardised extract can deliver less active material than a smaller, better-characterised dose.
Is it safe to take ashwagandha forever?
Nobody knows, and we are not going to pretend silence is reassurance. Almost every trial in this article ran eight to sixteen weeks. There is no good multi-year human data on continuous use. If your training is going well and your stress load is manageable, ashwagandha probably has little to offer you in the first place, and the trials producing the biggest numbers were in men who started stressed, untrained or fatigued.
Sources
- Wankhede S, Langade D, Joshi K, et al. Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial. J Int Soc Sports Nutr, 2015. View study
- Lopresti AL, Drummond PD, Smith SJ. A Randomized, Double-Blind, Placebo-Controlled, Crossover Study Examining the Hormonal and Vitality Effects of Ashwagandha (Withania somnifera) in Aging, Overweight Males. Am J Mens Health, 2019. View study
- Fornalik M, Malkiewicz A, Adamczak D, et al. Hormonal Modulation with Withania somnifera: Systematic Review and Meta-Analysis of Randomized-controlled Trials. Planta Med, 2026. View study
- Albalawi AA. Dual impact of Ashwagandha: Significant cortisol reduction but no effects on perceived stress — a systematic review and meta-analysis. Nutr Health, 2025. View study
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
