Ashwagandha and cortisol reduction: what the evidence actually shows.
|The claim, clearly stated
Specific proprietary ashwagandha extracts — most notably KSM-66 (root extract, 5% withanolides) — have been evaluated in randomised controlled trials. The evidence is sufficient to support a moderate-to-strong claim for stress reduction and modest cortisol lowering in chronically stressed adults.
| Evidence Summary | |||
|---|---|---|---|
| Perceived stress (PSS) | High | −30–40% vs placebo | Subjective measure; blinding varies |
| Serum cortisol | Moderate | −11–28% in stressed adults | Minimal effect in normal-range cortisol |
| Sleep quality (PSQI) | Moderate | Improved sleep latency and depth | Most trials 8–12 weeks; long-term limited |
| Recovery markers (CK) | Emerging | Small but significant in athletes | Limited RCTs; small samples |
| Testosterone (men) | Weak | Inconsistent across trials | Often in resistance-training context; confounding |
Key studies
|
Chandrasekhar et al. (2012) — Indian Journal of Psychological Medicine
RCT · n=64
KSM-66 300mg twice daily for 60 days: 27.9% reduction in serum cortisol, 44% reduction on the PSS scale. The 600mg/day dose is now the reference dose in subsequent trials. Double-blind, placebo-controlled · Low risk of bias |
|
Langade et al. (2019) — Medicine
RCT · n=60
KSM-66 at 300mg twice daily for 8 weeks in adults with insomnia. Sleep onset latency improved by 15 minutes vs +0.5 in placebo. PSQI total score improved 72%. Double-blind RCT · Low risk of bias |
