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
Sedative benzodiazepines, when used as a hypnotic to induce sleep, tend to be higher than amounts used to relieve anxiety, whereas only low doses are needed to provide a peaceful effect. Sedatives can be misused to produce an overly-calming effect (alcohol being the classic and most common sedating drug). In the event of an overdose or if combined with another sedative, many of these drugs can cause unconsciousness (see hypnotic) and even death. There is some overlap between the terms "sedative" and "hypnotic". Advances in pharmacology have permitted more specific targeting of receptors, and greater selectivity of agents, which necessitates greater