St. John's wort

St. John's Wort is a long-living plant with yellow flowers whose medicinal uses were first recorded in ancient Greece. St. John's Wort has been used for centuries for problems such as depression and anxiety. Its flowers are especially abundant around the middle of summer, and the plant may derive its name from the traditional celebration of John the Baptist's birthday on June 24.

The yellow flowers of St. John's Wort. Source: Wikimedia Commons

Other Names

• Hypericum
• Klamath Weed
• Goat Weed
• Hypericum perforatum (Latin)
• Amber Touch-and-Heal
• Hardhay
• Millepertuis
• Rosin Rose
• SJW
• Tipton Weed

How It Works

St. John's Wort contains many chemical compounds. The compounds that are believed to be the active ingredients that produce the herb's effects are hypericin and hyperforin. How these compounds work is not yet fully understood, but several theories have been suggested. Preliminary studies suggest that St. John's wort might work by preventing nerve cells in the brain from reabsorbing the chemical messenger serotonin, or by reducing levels of a protein involved in the body's immune system functioning.

Uses

St. John's Wort has been used for centuries to treat mental disorders and nerve pain. In ancient times, herbalists wrote about its use as a sedative and a treatment for malaria. It was also used as a balm for wounds, burns, and insect bites. Today, St. John's Wort is widely prescribed in Europe for depression. In the United States, there is public interest in St. John's Wort as a treatment for depression, anxiety disorders, and mild insomnia, but it is not a prescription medicine. It is, however, one of the most commonly used herbal supplements.

How St. John's Wort Is Taken

In the United States, St. John's Wort products are sold as:

• Capsules and tablets
• Teas— made up of the flower tops, which are packaged into tea bags or added loose to boiling water and steeped.
• Liquid extracts—specific types of chemicals are removed from the herb, leaving the desired chemicals in a concentrated form.

Side Effects

St. John's Wort has a variety of potential side effects, which include:

• Increased sensitivity to sunlight
• Anxiety
• Dry mouth
• Dizziness
• Diarrhea
• Fatigue
• Headache
• Sexual dysfunction

Interactions

Research shows that St. John's Wort interacts with some drugs. The herb affects the way the liver processes many drugs. In some cases, it may speed up or slow down a drug's breakdown. When combined with certain antidepressants, St. John's Wort may increase side effects such as nausea, anxiety, headache, and confusion. Drugs that may be affected include:

• Indinavir and possibly other drugs used to control HIV infection
• Irinotecan and possibly other drugs used to treat cancer
• Cyclosporine, which prevents the body from rejecting transplanted organs
• Digoxin, which strengthens heart muscle contractions
• Warfarin and related blood thinners
• Birth control pills
• Antidepressants

Because of these interactions, it is a good idea for a person using St. John's Wort to inform his or her healthcare provider about it. This helps to ensure safe and coordinated care.

It is important to remember that St. John's Wort has not been proven to effectively treat depression.

Controversy

Herbal products such as St. John's Wort are classified as dietary supplements by the U.S. Food and Drug Administration (FDA). The FDA's requirements for testing and obtaining approval to sell dietary supplements are different from its requirements for drugs. Unlike drugs, herbal products can be sold without requiring studies on dosage, safety, or effectiveness.

The strength and quality of herbal products are often unpredictable. Products can differ in content not only from brand to brand, but from batch to batch. Information on labels may be misleading or inaccurate.

In addition, "natural" does not necessarily mean "safe". Many natural substances can have harmful effects–especially if they are taken in large quantities or if they interact with other supplements or with prescription medicines.

Research

Scientific evidence regarding the effectiveness of St. John's Wort for depression is inconsistent.

There is some evidence that St. John's Wort is useful for treating mild to moderate depression:

• Mild-moderate depression was studied in Germany in 2006. Participants (332), were treated for six weeks with either St. John's Wort or placebo. The study found St. John's Wort was better than placebo in treating mild to moderate depression.^[1]

However, studies suggest that St. John's wort is of minimal benefit in treating major depression:

• Major depressive disorder was studied by the Hypericum Depression Trial Study Group in 2002. This study was included in the above analysis was cofunded by NCCAM and two other components of the National Institutes of Health (NIH)—the National Institute of Mental Health and the Office of Dietary Supplements. It was a large (340 participants), multi-center, double-blind, randomized study. It found that St. John's Wort was no more effective than placebo in treating major depression of moderate severity. However, the antidepressant sertraline, used in one arm of the study, also showed little difference from placebo.^[2]

Review articles are a good way to get information about the findings of a large number of studies. An analysis of the results of 37 clinical trials concluded the following:

• St. John's Wort may have only minimal beneficial effects on major depression. However, the analysis also found that St. John's wort may benefit people with minor depression. These benefits may be similar to those from standard antidepressants. Overall, St. John's Wort appeared to produce fewer side effects than some standard antidepressants. ^{[3] [4]}

Recent projects supported by NCCAM include studies of the:

• Safety and effectiveness of St. John's Wort for the treatment of minor depression
• Safety of St. John's Wort for the treatment of social anxiety disorder
• Effectiveness of St. John's Wort for the treatment of obsessive–compulsive disorder
• Effects of St. John's Wort on how well birth control pills work
• Possible adverse interactions of St. John's Wort and narcotic pain medicines
• Safety and effectiveness of St. John's Wort for attention deficit hyperactivity disorder

Clinical Trials

Clinical trials that may be currently recruiting for participants can be found at ClinicalTrials.gov.

References

1. ↑ Kasper S, Anghelescu IG, Szegedi A, Dienel A, Kieser M. Superior efficacy of St John's wort extract WS 5570 compared to placebo in patients with major depression: a randomized, double-blind, placebo-controlled, multi-center trial [ISRCTN77277298]. BMC Med. 2006 Jun 23;4:14. Abstract | Full Text | PDF
2. ↑ 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. Abstract | Full Text | PDF
3. ↑ De Smet PA. Herbal remedies. New England Journal of Medicine. 2002;347(25):2046–2056.
4. ↑ American Herbal Pharmacopoeia and Therapeutic Compendium. St. John's Wort (Hypericum perforatum). Monograph. American Herbal Pharmacopoeia; 1997.

External Links

• NIH Office of Dietary Supplements: Office of Dietary Supplements