Valerian root contains many different constituents, including volatile oils that appear to contribute to the sedating properties of the herb. Central nervous system sedation is regulated by receptors in the brain known as GABA-A receptors. According to test tube studies, valerian may weakly bind to these receptors to exert a sedating action.¹ This might explain why valerian may help some people deal with stress more effectively.²

Double-blind trials have found that valerian is an effective treatment for people with mild to moderately severe insomnia.^{3, 4} Generally, valerian makes sleep more restful as well as making the transition to sleep easier, but does not tend to increase total time slept, according to these studies. Two trials have also found that a combination with lemon balm is effective in improving quality of sleep and in treating insomnia.^{5, 6}