Posted by Alison on 21st September 2008
Valerian, known as garden heliotrope and by several other common names, grows wild in damp places in Europe, Asia, and North America. It is also cultivated. The plant is a perennial growing to three to four feet with big white, pink, or lavender flower clusters comprised of many individual flowers. The root and rhizome of the plant have a very strong odor and have long attracted attention for their ability to combat anxiety. Powdered root products and tinctures and extracts have official status in drug compendia in many European countries and in Canada. In Germany, valerian is listed for treatment of restlessness and nervous disorders of sleep. Until recent years it had official status in the United States, but now it can be sold only as a dietary supplement.
The root and rhizome of valerian contain 0.1 to 0.3 percent of a volatile oil that gives these plant parts their characteristic disagreeable odor. Remarkably, the compounds responsible for the anxiety and sedative effect of valerian are still not known despite valerian’s long history of medicinal use. The special combination of chemicals present in the root may be key to physiological effects observed. Studies using brain nerve terminals have shown that an extract of valerian root stimulates the release of a neurotransmitter in the body called GAB A. The resulting increase in brain GABA concentrations is likely to be how the plant improves sleep patterns and acts as a mild tranquilizer.
The roots, rhizomes, and extracts of valerian clearly have mild sedative and antianxiety effects in both laboratory animals and humans. But mild is the operative word. Valerian can be taken without a serious adverse effect and without the addiction potential so characteristic of sedative and tranquilizer drugs.
Evidence of Efficacy
Several clinical studies have evaluated the effect of valerian on sleep, but these studies have limitations because they tested a small number of patients or healthy volunteers and were short duration. Nevertheless, the consensus from an evaluation of the better studies is that valerian is effective as a mild sedative.
For example, in 1982 investigators from Switzerland studied 128 volunteers who look either placebo, valerian extract (400 mg), or a proprietary sleep product containing both valerian and hops. Each product was taken in random order on nonconsecutive nights. Study subjects filled out questionnaires on their nightly sleep patterns. Valerian helped people fall asleep sooner, and people reported they slept better, especially those who had previous sleep problems. (One problem with the study is that placebo was odor-free while valerian capsules had the plant’s characteristic odor.) Other scientific studies are in general agreement with these findings. There is little evidence to support the use of valerian as a mild tranquilizer, but most sedatives have antianxiety effect when taken in low doses.
Animal studies have suggested that there is a possibility of liver damage with high doses of valerian, but close examination of the studies shows that other compounds in the products being tested (skullcap, for example) may be the culprit. Humans have been using valerian for many centuries, and there are no reports of serious adverse effects. Liver damage was not even evident in overdose situations. Because valerian is a mild sedative, it makes sense to avoid alcoholic beverages or other drugs causing drowsiness when taking a valerian product. In addition, be careful operating machinery or an automobile while taking valerian during the day because of the potential for drowsiness. Taking valerian at night did not cause sedation or “daytime hangover” the next day. A benzodiazepine drug taken for comparison purposes did have a morning-after effect. Other occasionally reported side effects include headache, restlessness, nausea, and blurred vision.
Valerian has been used for a long time as a mild sedative and tranquilizer. Clinical studies support this use and indicate that occasional use is safe. We suggest, as with any medication for sleep and anxiety, that valerian be used only as a temporary measure to get past the problem. It is most important to deal with the underlying reason for anxiety or trouble sleeping and not rely on a drug to solve the problem.
For sleep, 400 mg of the powdered root before bedtime is appropriate. For use of the liquid forms or of the extracts, follow the directions on the manufacturer’s label. For anxiety, a lower dose taken two or three times a day could serve as a temporary measure, though we do not recommend self-medicating in this way. Because of the possibility that valerian may cause liver image in high doses, you should not use it if you have liver disease. Because the effects of valerian on the fetus have not been tested, it should be avoided during pregnancy and breast-feeding, and it should not be used in children. Avoid alcohol and other sedative drugs while taking it. On balance, valerian is an old and underutilized medication that is a safe and effective mild sedative.