Depression:
St. John's Wort for Treating Depression

If you surf the web or read your local newspaper, you've probably seen something about herbal supplements and their role in treating depression . While dozens of people swear by it, St. John's wort is still considered to be an alternative therapy by many experts.

A wild yellow flower considered to be a weed throughout most of the U.S., St. John's wort has been used for medical purposes in other parts of the world for thousands of years. Named for St. John the Baptist (because it blooms around the day of his feast), St. John's wort is continually being studied to try to validate its alleged benefits.

Over 30 clinical studies have been conducted over the past 22 years to evaluate the effectiveness of St. John's wort. The most recent scientific trials in the U.S. showed that St. John's wort is effective for mild depression but no better than placebo treatment for more severe cases of depression.

While the true benefits of St. John's wort are still being explored, if you do choose to use it, there are some things you need to know.

How Do I Take St. John's Wort?

Both the leaves and the flowers of St. John's wort are harvested, dried, and put into liquid or pill form. The dried leaves may also be used as a tea.

Typically 2-4 grams of powdered St. John's wort is taken three times a day for several weeks. It may also be taken twice a day as a tea made with 1-2 teaspoons of the dried herb.

Preparations in the U.S. have varied amounts of active ingredient in them, so be careful to note how much you're getting in your tablets.

What Should I Watch Out For if I Use St. John's Wort?

• Increased sensitivity to the sun -- especially if you are fair-skinned and taking large doses.
• Increased blood pressure.
• Stomach upsets.
• Allergic reactions.
• Fatigue and restlessness with long-term use.

Avoid taking St. John's wort:

• If you are taking any prescribed antidepressant.
• During pregnancy.

Research from the National Institutes of Health has shown that St. John's wort may reduce the effectiveness of several drugs, including birth control pills and some heart disease medications. Talk to your doctor about all the medications you are taking.

Always tell your doctor if you are taking St. John's wort or any other herbal product.

Things to Think About When Considering Use of Any Herbal Product

• Discuss any drugs you use, including herbal products, with your doctor.
• If you experience side effects such as nausea, vomiting, rapid heartbeat, anxiety, insomnia, diarrhea, or skin rashes, stop taking the herbal product and notify your doctor.
• Avoid preparations made with more than one herb.
• Beware of commercial claims of what herbal products can do. Look for scientific-based sources of information.

Select brands carefully. Only purchase brands that list the herb's common and scientific name, the name and address of the manufacturer, a batch and lot number, expiration date, dosage guidelines, and potential side effects.

Reviewed by the doctors at The Cleveland Clinic Department of Psychiatry and Psychology.

Edited by Cynthia Haines, MD, WebMD, July 2005.

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Last Editorial Review: 11/28/2005