melatonin benefits and risks

Melatonin may help you fall asleep and can be useful for jet lag, but it may not keep you asleep; high or inaccurately labeled supplement doses raise concerns about hormonal effects, especially for children and adolescents. 1 2

• Sleep onset, not staying asleep: It can help initiate sleep, but it does not reliably prevent waking during the night. 3
• Other biological effects: Natural melatonin is associated with increased bone mass, modulation of placental development, and antioxidant and potential anti-cancer effects. 4 5 6
• Hormonal risks: High melatonin can suppress reproductive hormones and affect gonadal function; the discussion raises concern that supplementation in children could affect puberty timing. 7 8
• Unreliable supplement doses: Tested products have contained substantially less or more melatonin than their labels state, making the actual dose—and therefore safety and effectiveness—uncertain. 9
• Behavioral alternatives: Light exposure and consistent sleep timing are favored as controllable approaches with a wider safety margin; light, exercise, and temperature can also help shift circadian timing. 10 11