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:
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
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
- 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.
Cynthia Haines, MD, WebMD, July 2005.
Portions of this page © The Cleveland Clinic
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Inc. All rights reserved.
Last Editorial Review: 11/28/2005