The German regulatory agency has approved valerian as an herbal remedy. The recommended dosage for treating insomnia is 300 to 900 mg taken 1 to 2 hours before bedtime. To treat anxiety, the approved dosage is 50 to 100 mg taken 2 or 3 times daily. Valerian is not considered a pharmaceutical in the U.S., so it's not regulated by the Food and Drug Administration.
Valerian can be taken in tea, it can be dissolved in a bath for transdermal absorption, and it's available in capsule, tablet and pill forms. Valerian is also available as an extract and a tincture.
Valerian may cause heart palpitations. It's most effective when taken for a period of 4 to 6 weeks, and the dose should be tapered off slowly. Problems are more likely to occur if you abruptly stop using valerian. It can cause weakened heartbeat and paralysis in patients with kidney disease.