also used for plants in the genus Stachys). Red valerian, often grown in gardens, is also sometimes referred to as "valerian", but is a different species (Centranthus ruber), from the same family but not very closely related. It is also called cat's love for its catnip-like effects. Valerian extract Phytochemicals Known compounds detected in valerian include: Alkaloids: actinidine, chatinine, shyanthine, valerianine, and valerine Isovaleramide may be created in the extraction process. Gamma-aminobutyric acid (GABA) Isovaleric acid Iridoids, including valepotriates: isovaltrate and valtrate Sesquiterpenes (contained in the volatile oil): valerenic acid, hydroxyvalerenic acid and acetoxyvalerenic acid Flavanones: hesperidin, 6-methylapigenin, and linarin Potential mechanism Because of valerian's historical use in traditional medicine for diverse purposes, such as for sedation or pain relief, laboratory research has been directed at the GABAA receptor, a class of receptors on which benzodiazepines act. Valeric acid, which is responsible for the typical odor of mostly older valerian roots, does not have any sedative properties. Valproic acid, a widely prescribed anticonvulsant, is a derivative of valeric acid. Valerian also contains isovaltrate, which has been shown to be an inverse agonist for adenosine A1 receptor sites. Hydrophilic extractions of the herb commonly sold over the counter, however, probably do not contain significant amounts of isovaltrate. Valerenic acid in valerian stimulates GABAA and serotonin receptors as a positive allosteric modulator and partial agonist, respectively. This includes the 5-HT5A which is implicated in the sleep-wake cycle. Preparation The chief constituent of valerian is a yellowish-green to brownish-yellow oil present in the dried root, varying in content from 0.5 to 2.0%. This variation in quantity may be determined by location; a dry, stony soil yields a root richer in oil than moist, fertile soil. Traditional medicine Although valerian is a common traditional medicine used for treating insomnia, there is no good evidence it is effective for this purpose. Valerian has not been shown to be helpful in treating restless leg syndrome or anxiety. The European Medicines Agency (EMA) approved the health claim that valerian can be used as a traditional herb to relieve mild nervous tension and to aid sleep; the EMA stated that although there is insufficient evidence from clinical studies, its effectiveness as a dried extract is considered plausible. The American Academy of Sleep Medicine's 2017 clinical practice guidelines recommended against the use of valerian in the treatment of insomnia due to poor effectiveness and low quality of evidence. Oral