Effects of Ashwagandha (Withania Somnifera) on stress and anxiety: A systematic review and meta-analysis

Arumugam V, et al.

Published in Explore (NY)

Methodology

Systematic review and meta-analysis searching MEDLINE, EMBASE, PubMed, PsycINFO and the Cochrane Library for randomised controlled trials published January 2000 to January 2022 of Ashwagandha (Withania somnifera) for stress and anxiety; two authors independently extracted data covering both subjective scales and objective markers.

Key Findings

Nine randomised controlled trials with 558 participants were pooled. Ashwagandha significantly reduced Perceived Stress Scale scores (mean difference -4.72, 95% CI -8.45 to -0.99), Hamilton Anxiety Scale scores (MD -2.19, 95% CI -3.83 to -0.55) and serum cortisol (MD -2.58, 95% CI -4.99 to -0.16) compared with placebo. Four of the nine trials reported mild to moderate adverse events. The authors conclude the benefit is real but that long-term safety data are lacking.

Conclusions

Ashwagandha formulations have beneficial effects on stress and anxiety.

Limitations

Only nine mostly small and short trials totalling 558 people, with wide confidence intervals that come close to no effect; preparations and doses varied, many ashwagandha trials are conducted or funded by extract manufacturers, and long-term safety (including reported liver injury signals) is not established.