Effect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysis

Kae Ling Cheah, Mohd Noor Norhayati, Lili Husniati Yaacob, Razlina Abdul Rahman

Published in PLOS ONE

Methodology

Systematic review and meta-analysis of five randomised controlled trials identified across CENTRAL, MEDLINE, SCOPUS and trial registries, pooling sleep outcomes with standardised mean differences.

Key Findings

Ashwagandha extract produced a small but significant improvement in overall sleep compared with placebo, with larger effects in trials using doses of at least 600 mg/day for 8 weeks or more and in adults diagnosed with insomnia. Anxiety levels and mental alertness on waking also improved.

Conclusions

Ashwagandha extract has a beneficial effect on improving sleep in adults, most clearly at doses of 600 mg/day or above sustained for eight weeks.

Limitations

Only five trials were eligible, several were small and conducted by the same research groups in India, and heterogeneity in extract type and sleep instruments limits generalisability.

Supplements Studied

Ashwagandha

Herb

Ashwagandha extract produced a small but significant improvement in overall sleep compared with placebo, with larger effects at doses of at least 600 mg/day for 8 weeks or more.

Outcomes Measured

Improved Sleep Quality

Primary

Ashwagandha extract produced a significant improvement in overall sleep quality compared with placebo.

Deep Sleep Enhancement

Ashwagandha extract exhibited a small but significant effect on overall sleep (Standardized Mean Difference -0.59; 95% Confidence Interval -0.75 to -0.42).