In the United States Valerian is sold as a nutritional supplement. Therapeutic use has increased as dietary supplements have gained in popularity, especially after the Dietary Supplement Health and Education Act was passed in 1994. This law allowed the distribution of many agents as over-the-counter supplements, and therefore allowed them to bypass the regulatory requirements of the Food and Drug Administration (FDA).
Valerian is used against sleeping disorders, restlessness and anxiety, and as a muscle relaxant. Valerian often seems only to work when taken over longer periods (several weeks), though many users find that it takes effect immediately. Some studies have demonstrated that valerian extracts interact with the GABA and benzodiazepine receptors. Valerian is also used traditionally to treat gastrointestinal pain and irritable bowel syndrome. However, long term safety studies are missing. Valerian is sometimes recommended as a first-line treatment when benefit-risk analysis dictates. Valerian is often indicated as transition medication when discontinuing benzodiazepines.
Valerian has uses in herbal medicine as a sedative. The main current use of valerian is as a remedy for insomnia, with a recent meta-analysis providing some evidence of effectiveness. It has been recommended for epilepsy but that is not supported by research (although valproic acid, an analogue of one of Valerian's constituents (valeric acid), is used as an anticonvulsant and mood-stabilizing drug). Valerian root generally does not lose effectiveness over time.