Valerenic acid is a sesquiterpenoid constituent of the essential oil of the valerian plant. Valerian is used as a herbal sedative which may be helpful in the treatment of insomnia. Valerenic acid may be at least partly responsible for valerian's sedative effects, in addition to the other valerenic acids hydroxyvalerenic acid and acetoxyvalerenic acid. Valerian supplements are often standardized to contain a particular amount of valerenic acid by weight (often 0.8%).