The claim
Marketing materials for ashwagandha supplements frequently state that the ingredient “eliminates stress”, “permanently lowers cortisol”, or “rewires your stress response”.
What the evidence actually shows
Multiple RCTs with standardised KSM-66 extract (300–600 mg/day, 8–12 weeks) consistently show:
- Cortisol reductions of 14–27% compared to placebo
- Statistically significant improvements in Perceived Stress Scale (PSS) and anxiety scores
- Effects are present during the supplementation period
This is genuine and meaningful evidence. The stress-reduction signal for ashwagandha is among the better-supported claims in the supplement space.
Where the claim goes too far
- “Eliminates” stress: No RCT shows complete elimination of stress responses. Mean cortisol reductions of 14–27% leave substantial cortisol activity intact.
- “Permanently”: Effects are not permanent. Studies show improvements during the intervention period; there are no long-term follow-up data demonstrating lasting effects after cessation.
- “Rewires your stress response”: No mechanistic human data support lasting neuroplastic changes. This is speculative language.
EFSA status
EFSA has not approved any health claims for ashwagandha. No EU-compliant health claim can legally be made on its basis.
Verdict
The core finding — that ashwagandha reduces cortisol and perceived stress during supplementation — is supported by moderate-quality evidence. The marketing language surrounding it (“eliminates”, “permanently”) is exaggerated and unsupported. The claim is therefore rated exaggerated.