Ashwagandha (Withania somnifera) has been used in Ayurvedic medicine for over 3,000 years, primarily as a rasayana — a rejuvenating tonic. Modern clinical research has validated several of its traditional uses, and some of the most compelling evidence relates specifically to men’s health. Here’s what the research actually shows.

Testosterone and Reproductive Health

This is where ashwagandha’s evidence for men is most notable. A well-conducted 2019 RCT published in Medicine found that men taking 600mg of ashwagandha extract daily for 8 weeks had significantly higher testosterone levels (+15%), DHEA-S levels, and improved sexual function compared to placebo. A 2022 double-blind RCT found 300mg twice daily increased testosterone by approximately 14.7% over 16 weeks.

The mechanism: ashwagandha’s withanolides appear to reduce cortisol — which directly suppresses testosterone production through the HPA-HPG axis — and may also support luteinising hormone (LH) secretion from the pituitary, which signals the testes to produce more testosterone.

Male Fertility

Multiple studies have found ashwagandha improves male fertility markers. A 2010 study of men with oligospermia (low sperm count) found that 225mg of ashwagandha root extract three times daily for 90 days significantly improved sperm count (+167%), sperm motility (+57%), and sperm volume. A 2015 study of men with stress-related fertility problems found similar improvements alongside reduced cortisol and oxidative stress markers in semen.

Muscle Strength and Body Composition

Ashwagandha has become popular in the fitness community — and the evidence supports this. A 2015 RCT of healthy men engaged in resistance training found that those taking 300mg of ashwagandha twice daily for 8 weeks gained significantly more muscle mass and strength compared to placebo, and had lower post-exercise muscle damage markers. The testosterone-boosting and cortisol-reducing effects both contribute: lower cortisol means less muscle protein breakdown (catabolism), and higher testosterone supports anabolic muscle growth.

Stress and Cortisol Reduction

This is ashwagandha’s best-evidenced benefit across all populations. A 2012 RCT found 300mg twice daily reduced serum cortisol by 27.9% and stress and anxiety scores by 44% over 60 days. For men, cortisol reduction has downstream benefits beyond stress relief — lower cortisol supports testosterone production, reduces abdominal fat accumulation, improves sleep quality, and supports immune function.

Physical Performance and VO2 Max

Several studies have found ashwagandha supplementation improves cardiorespiratory endurance. A 2015 study of healthy male adults found that those taking ashwagandha for 8 weeks showed significantly greater improvement in VO2 max (maximal oxygen uptake — the gold standard measure of cardiovascular fitness) than placebo. The study also found improved time to exhaustion in treadmill testing.

Dosage and Forms

Standard dose: 300–600mg of root extract twice daily (standardised to ≥5% withanolides)
KSM-66 and Sensoril are the two best-researched proprietary extracts — most clinical trials use one of these
Timing: Can be taken morning and evening; many take one dose before bed due to its cortisol-lowering and sleep-improving effects
Cycling: Some practitioners recommend cycling (8–12 weeks on, 4 weeks off) though the evidence for this is largely anecdotal

Frequently Asked Questions

What does ashwagandha do for men?

For men specifically, ashwagandha has strong evidence for: increasing testosterone (approximately 14–15% over 8–16 weeks), improving sperm count, motility, and volume, increasing muscle mass and strength when combined with resistance training, reducing cortisol (by up to 28%), and improving cardiorespiratory fitness (VO2 max).

Does ashwagandha actually boost testosterone?

Yes, modestly but measurably. Multiple double-blind RCTs have found approximately 14–15% increases in testosterone over 8–16 weeks of supplementation with standardised ashwagandha extract. The mechanism is primarily through cortisol reduction (which suppresses testosterone) and possible support of LH secretion from the pituitary.

How long does ashwagandha take to work for men?

Cortisol reduction and initial stress improvements typically become noticeable within 2–4 weeks. Testosterone increases and fertility improvements in the studies were measured at 8–16 weeks. Muscle and strength benefits in fitness studies typically became significant after 8 weeks of combined supplementation and resistance training.

Is ashwagandha safe for men to take daily?

Yes — daily ashwagandha supplementation at 300–600mg twice daily is well-tolerated in the clinical trials, which run 8–16 weeks. Rare side effects include mild gastrointestinal upset and, at very high doses, liver toxicity (though this appears to be dose-dependent and rare at standard doses). Men with thyroid conditions should consult a doctor as ashwagandha can modulate thyroid hormone levels.

This article is for informational purposes only. Consult a healthcare professional before supplementing with ashwagandha, particularly if you have hormone-sensitive conditions or take medications.

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