St John’s wort is a common name for Hypericum perforatum, a plant native to parts of Europe and Asia that has been used in traditional medicine in Europe for millennia. Extracts can be used in ointments for topical application or used in tablets or capsules for oral consumption. It has been used to treat a range of conditions, including wounds and menopausal symptoms, however, it is more widely known for its reported ability to treat depression.
The effectiveness of St John’s wort to treat these and other conditions has been formally assessed in dozens of randomised clinical trials. In particular, there have been several clinical trials conducted comparing St John’s wort to placebo for treating depression, as well as to standard antidepressants such as fluoxetine, imipramine and sertraline. For information on the results from randomised controlled trials select a condition below and download the related fact sheet.
St John’s wort has known drug interactions, including with warfarin, certain anti-depressants and birth control pills, some of which can be fatal. Therefore, as always, consult your physician before adding new treatments to your regimen or changing any current medication.