The reddish substance in the flowers of St. John’s wort contains numerous biologically active compounds, including hypericin and hyperforin.
(See also Overview of Dietary Supplements Overview of Dietary Supplements Dietary supplements are the most common therapies among integrative medicine and health (IMH) and complementary and alternative medicine (CAM), which include healing approaches and therapies... read more .)
Claims for St. John’s Wort
People take St. John’s wort mostly to relieve symptoms of mild to moderate depression Depression Depression is a feeling of sadness and/or a decreased interest or pleasure in activities that becomes a disorder when it is intense enough to interfere with functioning. It may follow a recent... read more .
St. John’s wort also has been used in the treatment of skin disorders, including psoriasis Psoriasis Psoriasis is a chronic, recurring disease that causes one or more raised, red patches that have silvery scales and a distinct border between the patch and normal skin. A problem with the immune... read more , and attention-deficit/hyperactivity disorder Attention-Deficit/Hyperactivity Disorder (ADHD) Attention-deficit/hyperactivity disorder (ADHD) is poor or short attention span and/or excessive activity and impulsiveness inappropriate for the child’s age that interferes with functioning... read more (ADHD) in children.
There are claims that St. John’s wort can inhibit HIV, the virus that causes AIDS. However, it interferes with the effects of many of the medications that are more effective for HIV infection.
Evidence for St. John’s Wort
A number of placebo-controlled studies have been done on St. John’s wort. Overall, these studies show St. John’s wort may benefit people with mild to moderate depression and may even be as effective as some traditional antidepressants. However, most studies do not show that St. John's wort is effective for major depression.
The effectiveness of St. John’s wort in treating ADHD or skin disorders has not been well-studied and is considered unproved.
St. John's wort may help relieve menopausal symptoms such as hot flashes.
Side Effects of St. John’s Wort
St. John’s wort may increase sensitivity to sunlight. Other side effects include dry mouth, constipation, fatigue, confusion, and, in people with bipolar disorder, mania.
During pregnancy, St. John’s wort increases muscle tone in the uterus and thus may increase the risk of a miscarriage.
Drug Interactions with St. John’s Wort
One of the larger problems with St. John’s wort is that it interacts negatively with a number of medications people take (see table ). These interactions may lead to toxic reactions or ineffectiveness of the medication.
Recommendations for St. John’s Wort
St. John’s wort may help ease symptoms of anxiety and mild to moderate depression. The American College of Physicians has stated that it may help symptoms of mild to moderate depression and may cause fewer side effects than conventional antidepressants.
However, St. John’s wort interacts negatively with many medications people take, so they should check with their doctor before taking it. Some countries have banned its use due to the numerous drug interactions.
Pregnant women and people taking medications for HIV infection should not take St. John’s wort.
More Information
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
National Institutes of Health's National Center for Complementary and Integrative Health: St. John’s Wort
Drugs Mentioned In This Article
Generic Name | Select Brand Names |
---|---|
st. john's wort |
No brand name available |