This is commonly dosed at 300 mg three times daily. Some people choose to take the 3 tablets in just two dose times to make it easier. The therapeutic effect is delayed for several weeks, similar to prescription antidepressants. The effect may be delayed even more in cases of severe depression. Side effects include nausea, diarrhea, insomnia, and fatigue, and anxiety.
Sexual dysfunction is uncommon but is seen at higher doses.
It speeds up a liver enzyme called 3A4 and 1A2, as well as a natural drug transporter called P-glycoprotein. This can effectively lower the level of many prescription drugs, including several immunosupressant and HIV drugs. Be sure to tell your doctor if you are taking St. John's Wort, and don't be too hard on him or her if they know little about the possible interactions. Serotonin syndrome is a very serious condition caused by high levels of serotonin, and is marked by flu-like symptoms, fluctuations in the body's regulatory systems, and muscle twitching or rigidity. I haven't found SJW to be terribly helpful, but I tend to work with folks with moderate to severe depression.