Its flowers and leaves are used to make medicine 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. John’s 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.
An oil can be made from St. John’s wort. Some people apply this oil to their skin to treat bruises and scrapes, inflammation and muscle pain, first degree burns, wounds, bug bites, hemorrhoids, and nerve pain. But applying St. John’s wort directly to the skin is risky. It can cause serious sensitivity to sunlight.
The active ingredients in St. John’s wort can be deactivated by light. That’s why you will find many products packaged in amber containers. The amber helps, but it doesn’t offer total protection against the adverse effects of light.