Current Use & What does the Science Say?

Today, valerian is used to treat various sleep disorders and anxiety. It is also used as a muscle relaxant and a mild sedative. Valerian is often preferred over pharmaceutical drugs, such as benzodiazepines, because it has fewer side effects. Although valerian has been used for centuries, the scientific evidence supporting its effectiveness remains unclear.

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One study investigated the effectiveness of valerian in treating elderly women with insomnia using a randomized, controlled, double blind, crossover design. Subjects were asked to take a valerian extract (V. officinalis L) or a placebo 30 minutes before bedtime and several sleep quality measures were taken. The results showed no difference between the valerian and the placebo groups in all measures. However, wake after sleep onset (WASO) increased significantly after 2 weeks with the valerian treatment, but not with the placebo. Based on these results, the authors concluded that valerian was not effective in treating elderly women with insomnia.

This study had several positive aspects. First of all, the crossover design allowed subjects to serve as their own control, thus minimizing the biological variation among the subjects. Proper blinding protocols were also applied, and the use of polysomnography provided objective measures of the sleep variables. Nevertheless, there were also some limitations to this study. Since participants were allowed to consume caffeine in the mornings or take naps, this may have confounded the effects of the treatment. In addition, the duration of the study may not have been long enough to observe a significant treatment effect as others have suggested that the effects of valerian on sleep are more long-term. Lastly, the small sample size and the strict inclusion criteria limit the applicability of these results to other sub-populations.

Koetter et al. (2007) examined the efficacy of a valerian/hops extract versus valerian only or a placebo.  A randomized, double blind, controlled, prospective trial was conducted on subjects who suffered from non-organic sleep disorder (defined by sleep latency >30 min). Subjects were randomly allocated into the 3 groups and measurements of sleep efficacy were done through self-reports; sleep latency being the primary outcome. Results revealed that the valerian/hops extract significantly reduced sleep latency compared to the placebo. Although the valerian extract showed improvement in sleep latency from baseline, it was no more efficient than the placebo.

The systematic techniques of this study were one of its positive qualities. Moreover, the negligible adverse side effects of the treatments suppors their safety for use. However, this study also presents a few limitations. For instance, the method for measuring the sleep parameters were not clearly described, making it difficult to determine whether these parameters were subject to methodological bias. Additionally, possible improper use of the home monitor system may have contributed to statistical errors.

As demonstrated by these studies and several others, valerian can be used for sedation or as sleep aids. However, its effectiveness may be dependent on the dose or the species of the plant. Overall, the mixed findings regarding the effects of valerian on sleep disturbances provides insufficient support for its efficacy, but combined formulations may be more effective.