Valerian root has been the primary herb of choice for supporting a restful sleep since the 9th century. Modern research has confirmed this traditional use, and has identified valerenic acid, a component of the essential oil, as primarily responsible for its relaxing effects. Planetary Herbals Full Spectrum Valerian Extract combines 450 mg of a concentrated standardized extract (yielding 0.8% valerenic acid) with 200 mg of organically cultivated whole valerian root. Combining these active constituents with the whole herb ensures that all the important compounds of the botanical are present.