Hypericum perforatumSt. JohnåÕs wort Powder is most commonly used for depression and conditions that sometimes go along with depression such as anxiety, tiredness, loss of appetite and trouble sleeping. There is some strong scientific evidence that it is effective for mild to moderate depression.Other uses include heart palpitations, moodiness and other symptoms of menopause, attention deficit-hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), and seasonal affective disorder (SAD).St. JohnåÕs wort has been tried for exhaustion, stop-smoking help, fibromyalgia, chronic fatigue syndrome (CFS), migraine and other types of headaches, muscle pain, nerve pain, and irritable bowel syndrome. It is also used for cancer, HIV/AIDS, and hepatitis C.