A systematic review of valerian as a sleep aid: safe but not effective.
Level 1 - systematic review of randomized trials
Systematic review of controlled clinical trials
PubMed 17517355 · doi:10.1016/j.smrv.2007.03.002
What was done
A systematic review evaluated computerized databases and reference lists to assess the efficacy and safety of valerian as a sleep aid, with attention to preparation types and subject characteristics. Out of 592 identified articles, 36 articles describing 37 studies met inclusion criteria: 29 controlled trials evaluated for efficacy and safety, and 8 open-label trials evaluated for safety only. Standardized forms and criteria were used for data extraction and quality assessment.
What was found
The abstract reports no numerical effect sizes, confidence intervals, or p-values. Most included studies found no statistically significant differences between valerian and placebo in healthy individuals, persons with general sleep disturbance, or those with insomnia. None of the most recent and methodologically rigorous trials found significant effects of valerian on sleep. Valerian was reported as safe with only rare adverse events.
Why it matters
Despite the widespread use of valerian as an over-the-counter sleep supplement, this systematic review indicates that rigorous evidence fails to support its clinical efficacy for insomnia.
Limits
The abstract provides qualitative conclusions rather than pooled quantitative meta-analytic estimates or exact participant sample sizes across the 37 studies. Heterogeneity in valerian preparations and subject populations may also limit generalized conclusions.
Cited by
- contradicts Saffron and valerian root are clinically supported ingredients that help people fall asleep and stay asleep.