Valerian for Insomnia: A Systematic Review and Meta-Analysis of Randomized Placebo-Controlled Trials

Abstract

Introduction: Valerian root is a popular herbal supplement used to treat insomnia and improve sleep quality. However, evidence of its efficacy is inconsistent. This systematic review aimed to evaluate the effect of valerian on sleep outcomes in adults with insomnia.

Methods: We conducted a systematic search of MEDLINE, CENTRAL, and Embase up to November 2019 for RCTs comparing any valerian preparation to placebo. The primary outcome was subjective sleep quality. Secondary outcomes included sleep latency and sleep duration.

Results: A total of 18 RCTs were included. A qualitative analysis revealed mixed results, with many studies suffering from methodological weaknesses. A meta-analysis of six studies that used a dichotomous outcome of "improved sleep" showed a modest positive effect (Relative Risk = 1.37, 95% CI: 1.05 to 1.78). However, there was no significant effect on sleep latency.

Discussion: The evidence for valerian as a treatment for insomnia is inconclusive. While some studies suggest a small subjective benefit, the findings are not consistent, and many trials are of poor quality. The lack of standardized preparations complicates the interpretation of the results.

Conclusion: Based on evidence from before 2020, there is insufficient support for the clinical efficacy of valerian in treating insomnia, though it appears safe for short-term use.