Melatonin may be effective for migraine headaches prevention. Compared to a placebo, a 3 milligram dose of Melatonin reduced the number of headache days in migraine patients. According to research results presented at the 2013 International Headache Conference, 178 patients were recruited for a trial. The trial compared 3 mg Melatonin, Amitryptylline (antidepressant), and placebo (no treatment). The number of headache days per month decreased by a factor of nearly three for patients taking Melatonin. The study concluded that Melatonin is effective for migraine prevention and is well tolerated by patients.