Friday, Jul 24, 2026 The claims desk. Receipts included. POWERED BY LENZ ↗
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HEALTH

The Claim

Ashwagandha supplementation effectively reduces stress and lowers cortisol levels in humans.

Verified by Lenz ·

The Short Version

Multiple systematic reviews and meta-analyses — including a 2025 BJPsych Open analysis of 15 studies — consistently show ashwagandha reduces perceived stress and cortisol levels compared to placebo. However, these benefits are best demonstrated in chronically stressed adults, not the general population. Evidence certainty is rated "low" with high heterogeneity across trials, at least one RCT found no cortisol effect in a specific subgroup, and long-term safety data remain limited. The claim is substantively supported but overstates universality.

Caveats

  • Effects are primarily demonstrated in chronically stressed adults; at least one meta-analysis found no significant stress reduction in non-stressed populations.
  • Evidence certainty across RCTs is explicitly rated 'low' with extreme heterogeneity (I²=83–94%), and publication bias and industry funding affect a substantial share of studies.
  • Long-term safety beyond ~12 weeks is understudied, with at least one 2026 case report linking prolonged high-dose use to HPA axis suppression.

The Receipts

  1. Study Details | NCT06793891 | Effects of Ashwagandha Extract on Stress Levels

    ClinicalTrials.gov

  2. Effects of Ashwagandha Supplements on Cortisol, Stress, and ...

    PubMed Central

  3. Effects of Ashwagandha Supplements on Cortisol, Stress, and Anxiety Levels in Adults: A Systematic Review and Meta-Analysis | BJPsych Open - Cambridge University Press

    BJPsych Open - Cambridge University Press

  4. Effects of Withania somnifera on Cortisol Levels in Stressed Human Subjects: A Systematic Review

    PubMed

  5. An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract

    PMC - NIH

  6. Does Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of randomized controlled trials - PubMed

    PubMed

  7. Systematic Review Findings Indicate that Ashwagandha Improves Physical Performance, Cognitive Health, and Mental Well-being

    herbalgram.org

  8. Ashwagandha extracts show promise in reducing stress hormones ...

    News-Medical.net

  9. Ashwagandha: Is it helpful for stress, anxiety, or sleep? - Health Professional Fact Sheet

    Health Professional Fact Sheet

  10. Supplements to Reduce Cortisol: Only One Has Strong Human Evidence

    InstalabMD

+ 10 more sources — see the full list on Lenz

Filed Under

AshwagandhaCortisol

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