Information On St John's Wort

St. John's wort is the common name for the herb Hypericum perforatum. The perennial originated in parts of Europe, Africa and Asia, and it now grows commonly in the United States. The National Center for Complementary and Alternative Medicine explains that documentation from ancient Greece describes St. John's wort being used medicinally even then. Doctors commonly prescribe St. John's wort in Europe to treat depression, but it is only sold as a dietary supplement in the United States.

Uses

The National Institutes of Health says that some short-term studies suggest St. John's wort can alleviate mild to moderate depression. American Family Physician reports that studies of using the herb to treat patients with major depression have resulted in conflicting findings. The herb may improve symptoms of somatoform disorders, which cannot be traced to a physical cause, though more research is needed. Researchers continue to study the use of St. John's wort in treating a myriad of other conditions, including anxiety, attention deficit disorder, obsessive compulsive disorder and premenstrual syndrome.

Forms and Dosing

In the United States, St. John's wort is available in capsule, tablet, dried herb, tincture and liquid extract form. St. John's wort is sold as a dietary supplement in the United States, which means that the Food and Drug Administration does not regulate the substance in the same way it regulates medication. The potency and contents of St. John's wort supplements vary. For treatment of mild to moderate depression, American Family Physician suggests a total of 900 mg per day, spread over two to three doses.

Side Effects

The National Center for Complementary and Alternative Medicine reports that some people may experience side effects when using St. John's wort. These side effects could include dry mouth, gastrointestinal problems, fatigue and greater sensitivity to sunlight. The National Institutes of Health also reports that some people could experience anxiety, headache, sexual dysfunction and skin reactions. People with bipolar disorder should not use St. John's wort because it could increase the risk of a manic episode.

Interactions

Those interested in taking St. John's wort should talk with their physicians, because it can interfere with the function of other medications and supplements. The herb has been clinically proven to decrease the effectiveness of oral contraceptives, certain anti-coagulants, allergy medication, cough medicine and other drugs. People with HIV should not take St. John's wort, because it can reduce the effectiveness of HIV medications.

Serotonin Syndrome

People who take anti-depressant medication should not take St. John's wort, because the combination of the medications could cause serotonin syndrome. Serotonin syndrome is a serious condition that can cause hallucinations, fever, confusion, nausea, vomiting, sweating and other symptoms. Severe serotonin syndrome can even lead to death.