Ashwagandha for Stress
Ashwagandha reliably lowers the stress hormone cortisol and improves clinician-rated stress, anxiety, and sleep scores in short trials, but the most rigorous 2025 analysis found no significant change in how stressed people actually felt, so the benefit is real but still preliminary.
Why this grade7-layer evidence engine
The evidence is consistent in direction but incomplete in depth, which is why this rates a B (preliminary). A 2025 meta-analysis of 713 people taking roughly 600 mg/day for eight weeks found a large reduction in stress symptoms (SMD -0.95) along with gains in anxiety, depression, and sleep (PMID 41140145), and a separate 2025 pooled analysis of 488 people confirmed a clear drop in cortisol (MD -1.16 ug/dL, p<0.001) (PMID 40746175). A small double-blind RCT (PMID 37832082) and an anxiety meta-analysis (PMID 39083548) point the same way.
What keeps the grade from going higher is a genuine gap. That same 2025 cortisol analysis found that perceived stress, how people rate their own stress, did not improve significantly (SMD -0.355, p=0.40), an objective-versus-subjective disconnect (PMID 40746175). Confidence is further tempered by very high heterogeneity in the anxiety data (I-squared 98%, PMID 39083548) and by industry funding of the supportive RCT (PMID 37832082).
Health authorities are supportive but cautious rather than endorsing. NIH ODS says extracts "may lower stress, anxiety, and cortisol levels" while flagging rare liver-injury cases; Mayo Clinic and Cleveland Clinic agree cortisol can fall but call the evidence limited and advise consulting a clinician. No major body, the FDA, WHO, Harvard, or the APA, recommends it as a first-line stress treatment, and the FDA has issued warning letters over disease claims.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.621
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (3 篇 > 0 negative)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status