Written by and verified by the Research Team. Last updated on Dec 20, 2013.

New evidence has come to light about the effects of a popular tea and herb: valerian (Valeriana officinalis). We’ve updated our page on the supplement because new evidence suggests valerian has no significant effect on sleep.

When first studied, valerian was thought to have positive effects on sleep, which led to it being marketed as a natural sedative herb. Researchers postulated that valerian was able to enhance the signalling of a major sedative neurotransmitter, called gamma-aminobutyric acid (GABA), to bring about its effects. Further human studies have found no quantifiable benefit to sleep. This means that despite many people reporting that they had a better night’s sleep after supplementing valerian, scientists were unable to observe any specific improvements, like a reduction in how long it took someone to fall asleep or how an increase in their total time spent asleep.

Though valerian may enhance GABAergic signalling, it also degrades into two molecules that actively compete with the sedative effects of this signalling. This may be the reason why initial research was so promising, but follow-up studies failed to find any benefits to sleep.

Valerian shows promise in relieving anxiety, but the evidence at this time is not strong enough to recommend it over other options. Further study is also needed to determine if valerian has a positive effect on sleep quality.