Evidence

Research on melatonin use for specific conditions shows:

• Circadian rhythm sleep disorders in the blind. Melatonin can help improve these disorders in adults and children.
• Delayed sleep phase (delayed sleep-wake phase sleep disorder). In this disorder, your sleep pattern is delayed two hours or more from a conventional sleep pattern, causing you to go to sleep later and wake up later. Research shows that melatonin reduces the length of time needed to fall asleep and advances the start of sleep in adults and children with this condition. Talk to your child's doctor before giving melatonin to a child.
• Insomnia. Research suggests that melatonin might slightly reduce the time it takes to fall asleep, but its effects on sleep quality and total sleep time aren't clear. Melatonin might be more beneficial for older adults who could be melatonin deficient.
• Jet lag. Evidence shows that melatonin can improve jet lag symptoms, such as alertness and daytime sleepiness.
• Shift work disorder. It's not clear whether melatonin can improve daytime sleep quality and duration in people whose jobs require them to work outside the traditional morning to evening schedule.
• Sleep disorders in children. Small studies have suggested melatonin might help treat sleep disturbances in children with a number of disabilities. However, good bedtime habits are usually recommended as an initial treatment. Talk to your child's doctor before giving melatonin to a child.

Research suggests that melatonin might reduce evening confusion and restlessness in people with Alzheimer's disease, but it doesn't seem to improve cognition.