Melatonin is a hormone your brain makes, not a sedative. Here is what the evidence supports, where common myths fall apart, and what to check before trying it.

This article is general information about everyday health habits, not medical advice. If you have a health condition, are pregnant or take regular medication, talk to your doctor or another qualified health professional before making big changes to your diet, activity or sleep. Figures come from US public health sources such as the CDC, HHS and the Dietary Guidelines for Americans.

Walk down the sleep-aid aisle and you will find shelf after shelf of melatonin, usually presented as a natural answer to restless nights. Use among American adults climbed from 0.6 percent in 2007 to 1.3 percent in 2012, with an estimated 3.065 million adults reporting use in the previous 30 days. Before you buy a bottle, it helps to know what the hormone actually does and what the evidence supports.

What Melatonin Actually Is

Melatonin is a hormone your brain makes in response to darkness. It helps set the timing of your circadian rhythms, the 24-hour internal clock, and it plays a role in sleep itself. Light exposure at night can hold back that production.

Research also suggests melatonin does other jobs in the body beyond sleep, though those effects are not yet well understood.

The supplements sold in stores are usually made synthetically rather than from animal sources. In the United States, melatonin falls into the dietary supplement category, which gets far less oversight than prescription or over-the-counter drugs.

Myth: Melatonin Is a Sleeping Pill

Melatonin is not a sedative. It is a timing signal. Your body already produces it, with levels rising at night and falling toward morning, and a supplement nudges that rhythm rather than forcing your brain to shut down. That is why the American Academy of Sleep Medicine describes strategically timed melatonin as an option for problems of sleep timing, including jet lag and the disruption shift work causes. The AASM suggests adjusting your bedtime routine and environment first, since many sleep problems respond better to habits than to supplements. A predictable evening routine, like the one in our An Evening Wind-Down Routine for Better Sleep, is a sensible place to start.

Fact: Where the Evidence Is Strongest

The strongest research involves sleep timing problems. Medium-sized reviews from 2010 and 2014 found melatonin may ease overall jet lag symptoms after eastward flights, and smaller studies suggest a benefit after westward flights too. For delayed sleep-wake phase disorder, where people struggle to fall asleep before the early morning hours, a 2016 review covering 52 people found melatonin shortened the time it took to fall asleep by about 22 minutes compared with a placebo. A 2018 randomized controlled trial of 307 people with the condition ran for four weeks.

For ordinary insomnia, the picture is narrower. Melatonin may help you fall asleep faster and feel less sleepy during the day, but it does not appear to improve other parts of insomnia, such as waking through the night. Clinical practice guidelines from 2017 and 2019 recommend against using melatonin to treat chronic insomnia. The most strongly recommended treatment is cognitive behavioral therapy for insomnia (CBT-I). If you are unsure what to aim for, see our guide to How Much Sleep Do Adults Need?

Myth: Natural Means Safe at Any Amount

Research has focused mostly on short-term use, and melatonin seems to hold up well over those periods. How it behaves with months or years of daily use is unknown. Natural does not mean harmless, either.

The CDC reports that melatonin ingestions in children reported to U.S. poison control centers rose 530 percent between 2012 and 2021, and by 2020 poison centers were fielding more reports of children swallowing melatonin than any other substance. More than 4,000 of those cases were serious enough to lead to hospital care, and 287 children needed treatment in an intensive care unit. A 2024 report estimated 11,000 emergency department visits for unsupervised melatonin ingestion by children aged 5 and younger between 2019 and 2022.

When a child takes too much, the warning signs tend to be headache, dizziness and unusual irritability. The American Academy of Sleep Medicine advises keeping melatonin out of reach of children and talking to a pediatric health care professional first. There is little evidence melatonin helps healthy children fall asleep, and many childhood sleep problems improve with changes to schedules, habits and routines instead.

Fact: What Is Actually in the Bottle

Because melatonin is regulated as a dietary supplement, no agency checks every bottle before it reaches the shelf. A 2017 analysis published in the Journal of Clinical Sleep Medicine examined 31 supplements from 16 brands and found that more than 71 percent of them contained an amount of melatonin that fell outside 10 percent of what the label promised. The actual content ranged from roughly 17 percent of the stated amount to close to six times that amount, and lot-to-lot variation within a single product reached 465 percent. Chewable tablets, the format children handle most often, showed the widest swings. The same analysis detected serotonin, a substance controlled far more tightly, in 26 percent of the supplements tested.

Small step: If you decide to try melatonin, look for the USP Verified mark. That mark indicates the product meets the standards of the U.S. Pharmacopeial Convention.

Myth: If Some Helps, More Helps More

High doses get promoted on the assumption that extra melatonin is harmless. A critical review of the research concluded that most claims about high-dose supplementation remain hypotheses, and that the experimental evidence behind them is limited and sometimes flawed. For perspective, your own nighttime melatonin levels are measured in tens of picograms per milliliter, so the hormone does its work in small amounts.

Melatonin can also affect more than sleep. It may lower blood pressure or blood sugar, so people who take medications for either should be monitored closely if they use it.

Questions to Ask a Pharmacist or Doctor First

A pharmacist or your doctor can help you decide whether melatonin makes sense for your situation. Useful questions include:

• Could my sleep trouble improve with schedule or habit changes first? Simple steps often help, such as a regular bedtime, less screen time before bed and cutting back on late-day caffeine, which we cover in Caffeine: How Much Is Too Much in a Day?
• Does melatonin interact with my medications or health conditions?
• What amount and timing would make sense for me, if any?
• Is this something I plan to take short term or long term?

Share a full list of supplements you take with anyone treating you. It helps them look after you properly.

Still wondering?

Does melatonin work for jet lag?

Reviews from 2010 and 2014 suggest melatonin may reduce overall jet lag symptoms after eastward flights, and smaller studies suggest a benefit after westward flights too. Timing matters, so ask a pharmacist about when to take it.

Is melatonin safe to give children?

The American Academy of Sleep Medicine advises talking to a pediatric health care professional first. There is little evidence it helps healthy children sleep, and ingestions among children have risen sharply.

Do I need a prescription for melatonin?

No. It is sold as a dietary supplement in the United States, which means less oversight than prescription or over-the-counter drugs. A USP Verified mark indicates a product meets U.S. Pharmacopeial Convention standards.

What should I try before melatonin?

A regular sleep schedule, dimmer evenings, less screen time before bed and a consistent wind-down routine help many people. For ongoing insomnia, cognitive behavioral therapy for insomnia is the most strongly recommended treatment.