With so many people turning to herbal remedies to relieve depression and anxiety, it's important to understand potential St. John's Wort side effects. St. John's Wort or hypericum perforatum is an herb used to relieve depression, anxiety and premenstrual syndrome or PMS. It has a mixed tract record when placed under scientific scrutiny in research trials, with some trials showing good results and others mixed or none at all. Like all herbs, it's not without potential side effects and possible drug interactions, so be sure to tell your doctor if you are taking this herb or any other herbal supplements.
Common St. John's Wort Side Effects
Most people tolerate St. John's Wort very well and experience few side effects. Medline Plus, from the U.S. National Library of Health and Medicine, states that St. John's Wort is "safe for most people." Like any herbal supplement it should be used according to the label directions since the potency may vary from manufacturer to manufacturer.
Several common side effects have been reported from people using this herb.
Sensitivity to Sunlight
St. John's Wort often causes photosensitivity, especially in light-skinned people. This makes them more prone to getting a sunburn. If you are taking St. John's Wort, use care and caution during activities that can expose your skin to sunlight. Wear long sleeves, long pants and a hat or sunscreen if you'll be out in the sun for any length of time.
Gastrointestinal Distress
Another common side effect reporter among people using St. John's Wort is stomach upset. The Mayo Clinic reports this among a litany of mild side effects. Stomach upset goes away once patients stop taking St. John's Wort. Symptoms may include burning feelings in the stomach, queasiness, or indigestion.
Sexual Side Effects
St. John's Wort may cause mild, temporary impotence or delayed ejaculation. Again, such side effects generally go away after people stop taking the herb.
Dizziness, Dry Mouth and Headaches
Other common side effects reported by people taking St. John's Wort are dizziness, dry mouth and mild headaches. Such side effects appear to be similar to those experienced by patients taking conventional medications to treat depression. If you experience dizziness, you should not drive a car or operate heavy machinery while taking this herb.
Elevated TSH
The Mayo Clinic website previously cited reports that one small study noted an increase in TSH or thyroid stimulating hormone among people taking St. John's Wort. This was but one study, however, and conclusions should not be drawn from one study. If you do suffer from any thyroid disease, you should talk to your doctor before taking St. John's Wort just to be on the safe side.
Drug Interactions
The FDA issued a warning about drug side effects reported with patients taking St. John's Wort concurrently with various medications. St. John's Wort uses the same metabolic pathway, cytochrome P450, as numerous other drugs, and thus can decrease their efficacy. It appears to affect several classes of drugs include antiviral drugs and drugs used to treat cancer, heart disease, depression and seizures. It may also render birth control pills less effective.
St. John's Wort side effects tend to be mild and go away when people discontinue using this herbal remedy. For those concerned about potential side effects, seek guidance from a qualified herbalist, naturopathic doctor, or another health care provider well-versed in herbal medicine.
