Valerian

• Valerian is an herb sold as a dietary supplement in the United States.
• Valerian is a common ingredient in products promoted as mild sedatives and sleep aids for nervous tension and insomnia.
• Evidence from clinical studies of the efficacy of valerian in treating sleep disorders such as insomnia is inconclusive.
• Constituents of valerian have been shown to have sedative effects in animals, but there is no scientific agreement on valerian's mechanisms of action.
• Although few adverse events have been reported, long-term safety data are not available.

What is valerian?

Valerian (Valeriana officinalis), a member of the Valerianaceae family, is a perennial plant native to Europe and Asia and naturalized in North America. It has a distinctive odor that many find unpleasant. Other names include setwall (English), Valerianae radix (Latin), Baldrianwurzel (German), and phu (Greek). The genus Valerian includes over 250 species, but V. officinalis is the species most often used in the United States and Europe and is the only species discussed in this fact sheet.

What are the historical uses of valerian?

Valerian has been used as a medicinal herb since at least the time of ancient Greece and Rome. Its therapeutic uses were described by Hippocrates, and in the 2nd century, Galen prescribed valerian for insomnia. In the 16th century, it was used to treat nervousness, trembling, headaches, and heart palpitations. In the mid-19th century, valerian was considered a stimulant that caused some of the same complaints it is thought to treat and was generally held in low esteem as a medicinal herb. During World War II, it was used in England to relieve the stress of air raid.

In addition to sleep disorders, valerian has been used for gastrointestinal spasms and distress, epileptic seizures, and attention deficit hyperactivity disorder. However, scientific evidence is not sufficient to support the use of valerian for these conditions.

How does valerian work?

Many chemical constituents of valerian have been identified, but it is not known which may be responsible for its sleep-promoting effects in animals and in in vitro studies. It is likely that there is no single active compound and that valerian's effects result from multiple constituents acting independently or synergistically.

Can valerian be harmful?

Few adverse events attributable to valerian have been reported for clinical study participants. Headaches, dizziness, pruritus, and gastrointestinal disturbances are the most common effects reported in clinical trials but similar effects were also reported for the placebo. In one study an increase in sleepiness was noted the morning after 900 mg of valerian was taken. Investigators from another study concluded that 600 mg of valerian (LI 156) did not have a clinically significant effect on reaction time, alertness, and concentration the morning after ingestion. Several case reports described adverse effects, but in one case where suicide was attempted with a massive overdose it is not possible to clearly attribute the symptoms to valerian.

Can valerian be harmful?

Few adverse events attributable to valerian have been reported for clinical study participants. Headaches, dizziness, pruritus, and gastrointestinal disturbances are the most common effects reported in clinical trials but similar effects were also reported for the placebo. In one study an increase in sleepiness was noted the morning after 900 mg of valerian was taken. Investigators from another study concluded that 600 mg of valerian (LI 156) did not have a clinically significant effect on reaction time, alertness, and concentration the morning after ingestion. Several case reports described adverse effects, but in one case where suicide was attempted with a massive overdose it is not possible to clearly attribute the symptoms to valerian.