St. John's Wort is a commonly-taken and well-supported treatment for mild to moderate depression. It may have other benefits, but also has serious risks of drug interactions. Use with antidepressants requires caution and strict coordination with the prescribing physician. Long-term use also requires consultation with a health care practitioner.
Although many people use St. John's Wort as long-term treatment, there is little evidence of long-term safety or efficacy. All of the clinical studies have been short (24-26 weeks at the most), and most have been small.
May trigger "cycling" in people with bipolar disorder.
Other common side effects, such as nausea, loose stools, and sun sensitivity, are easily addressed by taking food with each dose and using sunscreen.
There are insufficient data available at this time to recommend use of St. John's Wort by children or during pregnancy or breast-feeding.
St. John's Wort has serious potential interactions with many prescription medications, including antidepressants, birth control medications and others. The use of St. John's Wort should always be discussed with the prescribing physician.