Valerian, a flowering perennial native to Asia and Europe now naturalized throughout North America, has a reputation as a natural, mild sedative. It is approved in Europe as a treatment for stress-related anxiety and mild insomnia, and it is sold in the United States as a "generally recognized as safe" dietary supplement. However, clinical evidence of its effectiveness is conflicting. If you are affected by chronic stress, anxiety or sleep disturbances, talk to your doctor about the best course of treatment for you.
Background
Although the Valerianaceae family represents more than 200 species, Valeriana officinalis is the herb traditionally used to address anxiety, stress and insomnia. Hippocrates, who likely referred to the plant as "all-heal" or "phu," commonly prescribed the herb to promote restful sleep. Whether the herb healed all other ailments remains questionable, but the latter nickname aptly describes the pungent aroma of the roots, which is reminiscent of well-worn socks.
Chemical Composition
According to an article published in the American Family Physician written by Susan Hadley, M.D. and Judith J. Petry, M.D., the anti-stress properties of the herb are due to sesquiterpenes, such as valeric acid, and the amino acids gamma aminobutyric, tyrosine, arginine and glutamine. These agents, the authors say, work together synergistically to produce a sedative effect by stimulating certain neurotransmitters in the brain.
Pharmacological Effects
The University of Maryland Medical Center says that valerian may increase levels of gamma-aminobutyric acid in the brain. Gamma-aminobutyric acid, also known as GABA, is the primary neurotransmitter in mammals that regulates excitability in neurons. In effect, it works the same way as other agonists of GABA receptors do, including benzodiazepine drugs, to produce a sense of calmness. However, the sedative effect is milder and, typically, does not produce side effects, such as grogginess.
Clinical Evidence
Hadley and Petry reviewed several clinical trials and concluded that valerian is a safe and effective therapy for mild insomnia, although it appears that continuous supplementation for several weeks is needed for best results. However, there is less conclusive evidence that valerian effectively reduces stress and anxiety; the authors note that more research is needed to investigate the anxiolytic effects of valerian compounds. The National Institutes of Health echo this opinion, stating that many studies are flawed due to small sample size, poor study design and the use of varying concentrations of valerian preparations.
Safety Considerations
Although valerian is generally well-tolerated and not associated with serious side effects, the University of Maryland Medical Center advises that it should not be used while operating machinery or in combination with alcohol or other sedative medications, such as barbiturates, tricyclic antidepressants or anti-seizure medications. This herb may also interact with antihistamines, anti-fungal drugs and cholesterol-lowering medications. Finally, do not take this herb if you are pregnant or nursing.
