Valerian has long been used for sleep disorders and anxiety and has also been used for other conditions, such as headaches, depression, menopausal symptoms, sedation, irregular heartbeat, and trembling.
The research is not yet good enough to confirm those claims, but the risk appears to be minimal. Valerian in pregnancy or in association with hepatic disease is discouraged due to a lack of evidence. Safety for children has been more studied but is still controversial and can’t be recommended.
Valerian may increase drowsiness brought on by other drugs or herbs. It is advised that you shouldn’t take valerian with alcohol, tranquilizers or barbiturates. Valerian interacts with anesthetics and must be stopped before surgery.
Valerian can cause mild side effects, such as occasional stomach effects, headaches, dizziness, excitability, uneasiness, unsteadiness, low body temperature, tiredness the morning after its use, and a "hangover" from large doses. Similarly, "valerian withdrawal" may occur if the consumer stops using it suddenly after long-term high-dose use. This may entail confusion and rapid heartbeat. Long-term use may result in insomnia. Slight reductions in concentration and ability to perform complicated thinking may occur for few hours after taking valerian. Use caution if driving or operating heavy machinery.