Is it safe for an adult to take melatonin every night to help me fall asleep?

Best resource. Based on available studies and clinical use, melatonin is generally regarded as safe in recommended doses (five milligrams daily) for up to two years. Available trials report that overall adverse effects are not significantly more common with melatonin than placebo. http://www.mayoclinic.com/health/melatonin/ns_patient-melatonin/dsection=safety.