Ashwagandha (KSM-66)New

Reviewed Sep 4, 2026

Two independent 2024–2025 systematic reviews strengthen the evidence for standardized ashwagandha root extract in stress. A 2025 meta-analysis of 15 randomized controlled trials (873 adults; BJPsych Open) found that roughly 8 weeks of supplementation significantly lowered serum cortisol (mean difference −2.36 µg/dL, 95% CI −3.26 to −1.46), perceived stress on the PSS (−4.88 points, 95% CI −7.84 to −1.91), and anxiety on the Hamilton scale (−3.52 points, 95% CI −6.00 to −1.04) versus placebo. A separate 2024 meta-analysis of 9 RCTs (558 participants; Explore) independently reported closely matching reductions in perceived stress (−4.72 points), Hamilton anxiety (−2.19 points), and serum cortisol (−2.58 µg/dL). For sleep, a meta-analysis of 5 RCTs (400 adults; PLOS One) found a small-to-moderate improvement in overall sleep quality (standardized mean difference −0.59), most pronounced at doses of 600 mg/day or higher for 8 weeks or longer and in adults with insomnia. Effects on general quality of life were not statistically significant, and one 2025 review reported cortisol reductions without a consistent change in self-reported stress — so individual responses vary. Ashwagandha is generally well tolerated (mild drowsiness or GI upset are most common); rare reports of liver injury and thyroid hormone changes mean it should be used under clinical guidance, and it is not recommended in pregnancy, in hyperthyroidism or autoimmune thyroid disease, or alongside sedatives or thyroid medication without physician oversight. This is educational information, not a treatment for any condition — discuss supplementation with your physician.