Latin Name – Hypericum perforatum
St. John’s wort is a plant with yellow flowers whose use as an herbal remedy was first recorded in ancient Greece. The name St. John’s wort probably refers to John the Baptist, as the plant blooms around the time of the feast of St. John the Baptist in late June. The flowering tops of St. John’s wort are used to prepare teas and tablets containing concentrated extracts.
St. John’s wort has been used as an herbal remedy for centuries to improve mental health and for nerve pain. It has also traditionally been used as a sedative and for malaria, as well as a balm for wounds, burns, and insect bites.
Today, St. John’s wort is used as a nutritional supplement in the hope of improving depression, anxiety, or sleep disorders.
According to research, St. John’s wort may be useful for treating mild to moderate depression. However, two large studies, one sponsored by NCCAM, showed that the herb was no more effective than placebo in treating major depression of moderate severity.
Side Effects and Cautions
- St. John’s wort may cause increased sensitivity to sunlight. Other side effects can include anxiety, dry mouth, dizziness, gastrointestinal symptoms, fatigue, headache, or sexual dysfunction.
- Research shows that St. John’s wort interacts with some drugs. The herb affects the way the body processes or breaks down many drugs; in some cases, it may speed or slow a drug’s breakdown. Drugs that can be affected include:
- Birth control pills
- Cyclosporine, which prevents the body from rejecting transplanted organs
- Digoxin, which strengthens heart muscle contractions
- Indinavir and possibly other drugs used to control HIV infection
- Irinotecan and possibly other drugs used to treat cancer
- Warfarin and related anticoagulants
- When combined with certain antidepressants, St. John’s wort may increase side effects such as nausea, anxiety, headache, and confusion.
- St. John’s wort is not a proven therapy for depression. If depression is not adequately treated, it can become severe. Anyone who may have depression should see a health care provider. There are effective proven therapies available.
- Tell your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health to help ensure coordinated and safe care. Complementary or alternative therapy should not be used in place of conventional medical care or to delay seeking that care.
- National Center for Complementary and Alternative Medicine. St. John’s Wort and the Treatment of Depression. National Center for Complementary and Alternative Medicine Web site. Accessed June 29, 2007.
- St. John’s Wort. Natural Medicines Comprehensive Database Web site. Accessed June 29, 2007.
- St. John’s wort (Hypericum perforatum L.). Natural Standard Database Web site. Accessed June 28, 2007.
- St. John’s wort. In: Blumenthal M, Goldberg A, Brinckman J, eds. Herbal Medicine: Expanded Commission E Monographs. Newton, MA: Lippincott Williams & Wilkins; 2000:359–366.
- De Smet PA. Herbal remedies. New England Journal of Medicine. 2002;347(25):2046–2056.
- Hypericum Depression Trial Study Group. Effect of Hypericum perforatum (St. John’s wort) in major depressive disorder: a randomized controlled trial. Journal of the American Medical Association. 2002;287(14):1807–1814.
For More Information
The National Center for Complementary and Alternative Medicine (NCCAM) Clearinghouse
The NCCAM Clearinghouse provides information on CAM and NCCAM, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.
NIH Office of Dietary Supplements
Web site: ods.od.nih.gov
NIH National Library of Medicine’s MedlinePlus
St. John’s Wort Listing: www.nlm.nih.gov/medlineplus/druginfo/natural/patient-stjohnswort.html
Source: National Center for Complementary and Alternative Medicine, St. John’s Wort fact sheet, Created July 2005, Updated March 2008