Valerian (herb) particular binding site. Hydrophilic extractions of the herb commonly sold over the counter, however, probably do not contain significant amounts of isovaltrate. Valerenic acid in valerian stimulates serotonin receptors as a partial agonist, including 5-HT which is implicated in the sleep-wake cycle. 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. The volatile oils that form the active ingredient are pungent, somewhat reminiscent
Valerian (herb) green herb being bruised and applied to the head taketh away pain and pricking thereof." The name of the herb is derived from the personal name "Valeria" and the Latin verb "valere" (to be strong, healthy). Other names used for this plant include garden valerian (to distinguish it from other "Valeriana" species), garden heliotrope (although not related to "Heliotropium"), setwall and all-heal (which is 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