The news on St. John's wort (sometimes touted as "nature's Prozac") appears to keep changing. Some studies suggest the herb is effective; others question its worth. But the bottom line on the supplement's effectiveness for treating depression has generally stayed the same. Though U.S. sales of the herbal supplement plummeted in recent years -- triggered in part by news that it was of little use for severe illness -- the bulk of evidence from ongoing studies suggests that the age-old remedy is a reliable mood elevator for people with mild to moderate depression.
Uses: St. John's wort is taken for depression, anxiety, social phobia, seasonal affective disorder and mood changes linked to menopause and PMS. It's also sometimes used for muscle pain, gout, diarrhea, asthma, bronchitis and bed-wetting and applied topically for rashes and minor cuts and scrapes -- though there's slim evidence in support of such uses.
Dose: For depression, recommended doses range from 900 to 1,800 milligrams a day. It can take several weeks before the herb's effects are felt. St. John's wort is sold in pill and liquid form, but strength and concentration can vary from one manufacturer to another.
Precautions: Like many of its synthetic counterparts, St. John's wort can cause side effects such as nausea, dizziness, dry mouth, headaches and upset stomach. Long-term, high-dose use can also make skin more sensitive to sunlight. And the herb may worsen serious mental conditions such as schizophrenia. St. John's wort can also lower blood levels of many drugs, including HIV drugs, heart medications and oral contraceptives. So don't self-prescribe it if you're taking any of these drugs or prescription antidepressants.
Research: Clinical trials in the U.S. and Europe have shown St. John's wort to be as effective as Prozac, Tofranil and other antidepressants in treating mild and moderate depression. In recent years, a couple of American studies have suggested that St. John's wort is not effective in treating patients with major depression. But earlier this month, a well-designed German study published in the British Medical Journal showed that St. John's wort was as effective as Paxil -- with less frequent side effects -- in treating patients with moderate to severe depression. The researchers are now looking at how good the herb is at treating depression over the long term.
Dietary supplement makers are not required by the U.S. government to demonstrate that their products are safe or effective. Ask your healthcare provider for advice on selecting a brand.
-- Elena Conis