St. John’s Wort

St. John’s wort (Hypericum perforatum) is a yellow-flowering weed that has been used to treat various "nervous disorders" for centuries. It is sold, usually by prescription, in Germany as an antidepressant, and in the U.S. as a dietary supplement. This herb contain at least seven groups of compounds that can have pharmacological action.

Claims, purported benefits: Alleviates depression, anxiety, and sleep disorders.

Evidence: St. John’s wort is one of the most researched herbal medicines, in particular for its use in depression. But results have often been inconsistent and hard to compare, largely because the studies have included people with different types and degrees of depression, used different herb preparations and doses, tested the herb against low doses of antidepressants, and/or did not have placebo groups.

Still, most studies have been favorable, and the consensus is that St. John’s wort works better than a placebo in treating people with mild-to-moderate depression, at least in the short term. It also seems to be as good as older-generation tricyclic antidepressants and possibly newer antidepressants (SSRIs), such as fluoxetine (Prozac) and sertraline (Zoloft), for people with this level of depression.

Bottom line: If your depression is interfering with your life, talk to your doctor or a therapist. Depression is a serious condition, and you should not self-diagnose or self-medicate. While there is continuing debate about how effective prescription antidepressants really are, beyond their powerful placebo effect, these drugs are still often a first-choice treatment, especially for more severe depression. It is often hard to draw the line between severe and mild-to-moderate depression.

If, after consulting your doctor, you want to try St. John’s wort for mild-to-moderate depression, keep in mind that the herb interacts with many drugs (including statins, blood thinners, and HIV drugs) and that, because supplements are not regulated, you don’t really know what you are getting. If you are already taking a prescription antidepressant, you should not switch to St. John’s wort on your own. And you should not combine the two, since that can increase side effects, especially in older people.