Side effects of melatonin are few but may include daytime sleepiness and tiredness on waking. Headaches and dizziness also can occur when taking melatonin supplements. Less common side effects can include abdominal pain, mild anxiety, irritability, confusion and feelings of depression. If you’re considering taking a melatonin supplement to help you sleep, talk with your health care provider first. Your health care provider may recommend adjusting medication or supplement dosages for the best effects on your overall health. https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-q-and-a-melatonin-may-help-you-sleep/