Nobody has discovered which element in the plant might produce the sedative effects, so valerian is hard to standardize. It may help you fall asleep, but may not improve the quality of sleep. Don't combine it with alcohol, tranquilizers, or barbiturates. Shakespeare spoke several times of sleep-inducing herbs. Valerian, a popular herbal sleeping pill today, was known as a medicinal plant in Roman times and takes its name from an ancient Roman province.
Some people add it to bath water and apply it to their skin.
Research results have been unclear. In some experiments a dose of valerian before retiring seems to reduce the time it takes to fall asleep. But it has yet to be shown in a well-designed trial that valerian improves the quality of sleep, once you conk out. Nobody has yet discovered what element in the plant might produce the sedative effects, if any. Valerian has proved toxic in one animal study.