Safety and efficacy of Withania somnifera for anxiety and insomnia: Systematic review and meta-analysis

Despite the historical neurological use of Withania somnifera, limited evidence supports its efficacy for conditions like anxiety and insomnia. Given its known anti-stress properties, this review evaluated its safety and efficacy for anxiety and insomnia.

We searched Medline, Cochrane Library, and Google Scholar until August 2023 for randomized controlled trials (RCTs) comparing W. somnifera to placebo in patients with anxiety and/or insomnia. Outcome measures included changes in anxiety levels via the Hamilton Anxiety Scale (HAM-A), Sleep Onset Latency (SOL), Total Sleep Time (TST), Wake After Sleep Onset (WASO), Total Time in Bed (TIB), Sleep Efficiency (SE), and Pittsburgh Sleep Quality Index (PSQI) score. We utilized a random-effect model for pooling Mean Differences (MD) with a 95% Confidence Interval (CI). Heterogeneity was assessed through sensitivity and subgroup analysis, and the quality of RCTs was evaluated using the Cochrane revised risk of bias tool.

Pooled results from five RCTs (n = 254) demonstrated that W. somnifera significantly reduced HAM-A scores (MD = -5.96; [95% CI -10.34, -1.59]; P = 0.008; I² = 98%), as well as sleep parameters such as SOL, TST, PSQI, and SE, but not WASO and TIB.

While W. somnifera extracts yielded promising results, further research with larger sample sizes is needed to confirm its effects on anxiety and insomnia.