Melatonin for Sleep: Does It Work, How Much to Take, and Is It Safe?

Melatonin is made by the pineal gland in the brain when it gets dark, and it signals to the body that night has started. Bright light, including from phones and screens, suppresses it. Supplements copy that signal. That makes melatonin useful for problems of timing — jet lag, shifted sleep schedules — but less useful when the problem is lying awake with a racing mind.

Does melatonin help you sleep?

A little. A 2013 meta-analysis in PLoS One of 19 placebo-controlled trials with 1,683 people found melatonin reduced the time to fall asleep by about 7 minutes and increased total sleep by about 8 minutes, with a small improvement in sleep quality. The effect did not wear off with continued use, and it was larger at higher doses and longer durations. But it is modest — smaller than prescription sleep medicines. The American Academy of Sleep Medicine's 2017 guideline suggests that clinicians not use melatonin to treat chronic insomnia in adults.

Does melatonin work for jet lag?

Yes — this is its best-supported use. A Cochrane review found 9 of 10 trials showed melatonin, taken close to the target bedtime at the destination (10 pm to midnight), reduced jet lag after flights crossing five or more time zones. Doses from 0.5 to 5 mg were similarly effective, although people fell asleep faster on 5 mg; above 5 mg added nothing. Timing matters: taken at the wrong time, early in the day, it can cause sleepiness and delay adjustment. Useful for Pakistanis flying to the UK, North America or Australia to visit family.

How much melatonin should I take?

Less than most products contain. For jet lag, 0.5–5 mg worked equally well, so start at the low end, about 1–2 hours before your intended bedtime. There is no benefit in taking 10 mg or more, and higher doses are more likely to leave you groggy the next morning. If you need it for more than a few weeks, talk to a doctor about why you are not sleeping.

Is the dose on the label accurate?

Often not. A 2017 study in the Journal of Clinical Sleep Medicine tested 31 melatonin supplements. The actual melatonin content ranged from 83 percent less to 478 percent more than the label claimed, more than 71 percent of products were not within 10 percent of the label, and different batches of the same product varied by up to 465 percent. Eight contained serotonin, a related compound that should not be there. Buy from reputable pharmacies and brands, and be cautious with imported gummies of unknown origin.

Is melatonin safe?

• Short-term use in healthy adults appears safe; common side effects are next-day drowsiness, headache and dizziness.
• Do not drive or operate machinery if it leaves you drowsy.
• Keep it out of children's reach. US poison centres recorded 260,435 melatonin ingestions by children and teenagers from 2012 to 2021, a 530 percent rise; five children needed a ventilator and two died. Gummies look like sweets.
• Do not give melatonin to children without a doctor's advice.
• Talk to your doctor first if you take blood thinners, epilepsy medicines, diabetes medicines, blood pressure medicines or other sleeping tablets, or if you have an autoimmune condition.

What works better than melatonin for poor sleep?

• A fixed wake-up time every day, including weekends — the most powerful signal to your body clock.
• Bright light, ideally daylight, in the morning; dim lights and screens in the last hour before bed.
• No caffeine after early afternoon — that includes tea and cola. See our coffee and caffeine guide.
• Exercise during the day, but not hard training right before bed if it keeps you awake.
• A lighter, earlier dinner rather than a heavy meal at 11 pm.
• Cognitive behavioural therapy for insomnia (CBT-I), the first-line treatment recommended by sleep medicine guidelines for chronic insomnia.
• If you snore loudly or wake unrefreshed, check for sleep apnoea — see our sleep apnoea guide.

This article is general information, not medical advice. Talk to your doctor before taking melatonin if you take regular medicines or have a long-term condition, and see a doctor about insomnia that lasts more than a few weeks.