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What is St. John’s wort?

St. John’s wort is an herbal remedy that comes from the plant, Hypericum perforatum. There are at least ten active compounds in St. John’s wort. Many people believe that St. John’s wort can improve symptoms of anxiety and mild depression. Some research studies showed that St. John’s wort is equal or less effective to the older antidepressants like amitriptyline (brand name Elavil) and imipramine (Tofranil). Recent studies have also reported that St. John's wort reduces symptoms of mild to moderate depression just as well as newer antidepressants such as fluoxetine (Prozac) and sertraline (Zoloft). Longer term studies are needed to confirm and validate these effects.

Please talk with your doctor before starting St. John’s wort. It may take up to eight weeks to feel the full effects of this herb. If you don't notice improvement after four to six weeks, let your doctor know.

St. John’s wort is available in drops, extracts, capsules, tablets, and powders. In most research for depression, people took an extract containing 0.3 percent hypericin at a dose of 300 mg three times a day.

Sources:
Gaster, B., Holroyd, J. “St. John’s wort for depression: a systematic review,” Archives of Internal Medicine 24 (2000).
The Review of Natural Products. Facts & Comparisons, 2007.
Robbers, J.E., V.E. Tyler. Tyler’s Herbs of Choice: The Therapeutic Use of Phytomedicinals. The Haworth Press, 1999.
Philipp, M. "Hypericum Extract versus Imipramine or Placebo in Patients With Moderate Depression: Randomised Multicentre Study of Treatment for Eight Weeks," British Medical Journal 319 (1999).
Woelk, H. "Comparison of St John's Wort and Imipramine for Treating Depression: Randomised Controlled Trial," British Medical Journal 321 (2000).
Brenner, R. "Comparison of an Extract of Hypericum (LI 160) and Sertraline in the Treatment of Depression: A Double-blind, Randomized Pilot Study," Clinical Therapeutics 4 (2000).
Schrader, E. " Equivalence of St John's Wort Extract (Ze 117) and Fluoxetine: A Randomized, Controlled Study in Mild-moderate Depression," International Clinical Psychopharmacology 15 (2000).
Micromedex® Healthcare Series. Thomson Micromedex, 2007.