Valerian is a perennial plant native to Europe and Asia that has been used as a medicinal herb since ancient times to aid sleep. The dried roots are used medicinally and studies suggest it may be useful for insomnia. Valerian can be taken in tablet form containing 150-300mg of valerenic acid or as a tea made from 2-3 grams of dried root. Pregnant or nursing women and children under 3 should not take valerian without medical advice due to lack of research on safety.