Valerian (Valeriana officinalis) has a long history of use as an herbal remedy for insomnia and other sleep disorders. Its use dates back to ancient Greece and Rome, where it was often prescribed as a sedative. In modern times, valerian root is commonly found in over-the-counter sleep aids and herbal teas formulated to promote relaxation and improve sleep quality.

Scientific investigation into valerian’s efficacy for insomnia has produced mixed results. Several randomized controlled trials and meta-analyses suggest valerian may have a modest benefit in improving sleep quality and reducing the time it takes to fall asleep, but the overall quality of evidence is low to moderate. Many studies suffer from methodological issues, such as small sample sizes, lack of blinding, and variability in valerian preparations and dosages. Some meta-analyses, such as a 2020 Cochrane review, concluded that there is insufficient evidence to firmly support valerian as an effective treatment for insomnia, although some individuals may experience subjective improvement.

The active compounds in valerian, such as valerenic acid, are thought to interact with gamma-aminobutyric acid (GABA) receptors in the brain, producing a sedative effect. However, definitive mechanisms of action remain unclear. In summary, valerian is widely used for insomnia, supported by both tradition and some scientific evidence, but robust clinical validation is lacking.