Valerian for Insomnia on Subjective and Objective Sleep Parameters: a Meta-analysis of Randomized Controlled Trials

Purpose of Review This systematic review and meta-analysis aimed to assess the effects of valerian intervention for insomnia on both subjective and objective sleep parameters. Recent Findings Twenty-one RCTs with a total of 1433 participants were retrieved after searching on 6 electronic databases. The results indicated that, for subjective parameters, valerian may have a small to moderate effects on PSQI score (standardized mean differences (SMD), −1.21; 95% CI [−1.92 to −0.51]), self-reported dichotomous outcome of sleep quality (risk ratio (RR) =1.37; 95% CI [1.13 to 1.68]), and self-reported sleep duration (RR=1.27; 95% CI [1.02 to 1.57]). For objective parameters, valerian only have significant effect on the length of non-rapid eye movement (NREM) stage 3 (SMD= 0.89; 95% CI [0.35 to 1.43]) of the patients. Heterogeneity was mainly due to varied study designs, especially in preparation, outcomes measured, duration of follow-up, and populations. Summary Valerian intervention for insomnia may improve PSQI scores, subjective dichotomous outcomes of sleep quality and duration, and time of NREM stages 3.