Native to Europe and parts of Asia, valerian has been introduced into North America. It is consumed as food by the larvae of some Lepidoptera (butterfly and moth) species including Grey Pug.

Other names used for this plant include garden valerian (to distinguish it from other Valeriana species), garden heliotrope (although not related to Heliotropium) and all-heal. Red valerian, often grown in gardens, is also sometimes referred to as "valerian", but is a different species (Centranthus ruber) from the same family and not very closely related.

Valerian, in pharmacology and phytotherapic medicine, is the name of an herb or dietary supplement prepared from roots of the plant, which, after maceration, trituration and dehydration processes, are packaged, usually into capsules. Based on its pharmacological mode of action, valerian root has been demonstrated to possess sedative and anxiolytic effects.^[1]

Medicinal use

Valerian is used for insomnia and other disorders as an alternative to benzodiazepine drugs, and as a sedative for nervous tension, hysteria, excitability, stress and intestinal colic or cramps.^{[18][19][20][21]}

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 for sleeping disorders, restlessness and anxiety, and as a muscle relaxant. Certain data suggests that valerian has an effect that is calming but doesn't cause sleepiness the following day.^{[citation needed]} When used as a sleeping aid, valerian appears to be most effective on users who have difficulty falling asleep. Also noteworthy is that valerian has been shown to have positive results on users who wake up during the night.^[22] Valerian often seems only to work when taken over longer periods (several weeks), though some users find that it takes effect immediately. Some studies have demonstrated that valerian extracts interact with the GABA receptors. Valerian is also used traditionally to treat gastrointestinal pain and irritable bowel syndrome. However, long term safety studies are absent.

Valerian is sometimes recommended as a first-line treatment when risk-benefit analysis dictates. Valerian is often indicated as transition medication when discontinuing benzodiazepines.

Valerian has uses in herbal medicine as a sedative. Results of investigations into its effectiveness have been mixed.^[23] It has been recommended for epilepsy,^{[citation needed]} 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.

One study found valerian tends to sedate the agitated person and stimulate the fatigued person, bringing about a balancing effect on the system.^[24]

One study found valerian effective in controlling infantile rota viral diarrhea.^[25]

In ayurveda, valerian is considered to work on the nervous, digestive, and respiratory systems as a stimulant, antispasmodic, stomachic, sedative, analeptic, carminative, and nervine. While it is used for various disorders of these systems, it is noted that excessively, it may dull the mind or cause severe conditions such as central paralysis, thus it is recommended to be used under the supervision of an ayurvedic doctor. Possibly because of its dulling effects, another herb is mainly used for nerve and mind disorders like insomnia: jatamamsi (Nardostachys jatamansi).^[26]