Source: Ashwagandha RCT (Salve 2019) — 300–600 mg/day of KSM-66 root extract lowered cortisol and stress scores over 8 weeks.
An adaptogenic herb used in Ayurveda for stress. KSM-66 is the most-studied root extract.
Modulates the HPA (stress) axis, blunting the cortisol response.
Serum cortisol fell 27.9% vs 7.9% on placebo (p=0.0006), with large drops in perceived-stress scores.
Double-blind RCT · n=64 · 600 mg/day, 60 days — Chandrasekhar et al., 2012 — Indian J Psychol Med
Improved sleep quality and sleep-onset latency in adults with diagnosed insomnia versus placebo.
Double-blind RCT · n=60 · 600 mg/day, 10 weeks — Langade et al., 2019 — Cureus
Pooled data show a small-to-moderate benefit on sleep, strongest at 600 mg/day for 8+ weeks.
Meta-analysis of 5 RCTs · n=400 · ≥600 mg/day, ≥8 weeks — Cheah et al., 2021 — PLOS ONE (meta-analysis)
Bottom line: Among the better-evidenced herbs here: multiple human RCTs converge on real reductions in cortisol and perceived stress, with a smaller but consistent sleep benefit — nearly all at the 600 mg/day KSM-66 dose used in the trials.
Generally well tolerated. Can cause drowsiness or mild GI upset. Avoid with hyperthyroidism, in pregnancy, and with sedatives; rare liver-injury reports exist.
Anecdotes, not evidence, and not medical advice. Frequency labels are our read of forum sentiment, not a formal survey. Individual responses vary widely.
| Per serving | |
|---|---|
| Typical branded single-ingredient product | $0.67 |
| Bulk powder at the clinical dose (250g, $23.97) | $0.06 |
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Bulk price: $23.97/250g → Alt source: $19.99/125gEducational only — not medical advice. Grades and clinical doses are computed from public labels against sourced research (citations on the main site); prices last verified 2026-07-21. Expensive Powder has no sponsors; bulk links may earn an affiliate commission, which never affects a grade. Talk to a clinician before starting any supplement.