Is it okay to take melatonin every night?

You may have taken it most evenings for months and still not be able to say, hand on heart, whether it helps. Some nights you sleep and some nights you don't, and underneath runs a half-worry that a hormone every night must be doing something to you, or that you couldn't sleep now without it. And there's a faint sense, too, that needing something every night is a small failure of your own.

The longest trial speaks to that worry. People with insomniainsomnia Trouble falling asleep, staying asleep or waking too early, that keeps happening and affects how you feel or get on during the day. took a prolonged-release tablet, the kind that lets its dose out slowly, every night for six months. Their side effects, blood tests and hormone measures looked much like those of people on a dummy pill⁴4 Wade et al., 2010, and the tablet showed no sign of wearing off. Six months is as far as the evidence reaches, and there isn't good research on years¹²1 Besag et al., 20192 NCCIH, 2024 of nightly use.

Melatoninmelatonin A hormone your brain releases as darkness falls, telling the rest of your body that night has come. It's also sold as a tablet. is the message your brain sends as the dark comes on, telling the rest of you what hour it is, and it doesn't push you under the way a sleeping pill does. So when you take it matters far more than how much. Once you see it that way, you can start to tell whether your own trouble is the kind it can answer.

Think of the hour you usually reach for the tablet, when the light outside is going. As it goes, your body clockbody clock The timekeeper in your brain that runs on a cycle of about a day, setting when you feel sleepy and when you feel alert. Daylight, especially in the morning, keeps it in step with the clock on the wall. sets the brain making melatonin, and the rising level tells the rest of you that the day is done²⁵2 NCCIH, 20245 Zisapel, 2018. In the morning, light switches it off again. The steep climb into sleepiness tends to come about two hours after⁵ your own melatonin starts. A tablet shows its effect most clearly when your own level is low, as it is around midday, and does least once the evening rise is under way⁵. Swallowed at lights-out, then, a large dose joins a rise that's already under way, and probably tells your body something it already knows.

In one laboratory study, twenty healthy men took melatonin just before noon, when their own level was low, and they grew sleepier at every dose from 0.1 to 10 milligrams⁶6 Dollins et al., 1994. A later review, written by a researcher tied to a melatonin maker, finds that it isn't sedating⁵ in the way sleeping pills are, which can sound like the opposite. Read side by side, the two papers fit the hour: melatonin seems to make people sleepy when the body's own supply is low, and to add little once the evening has already done that work.

If you take your tablet beside a bright laptop or under the kitchen lights, that light may be working against it. In a laboratory study of 116 healthy young adults, ordinary room light in the hours before bed delayed the start of their melatonin in ninety-nine percent of them⁷7 Gooley et al., 2011, and cut about ninety minutes from its nighttime run compared with dim light. There's more on that in how light affects sleep.

The clearest picture comes from a laboratory where thirty-four healthy adults lived in dim light and took one pill a day at a set hour, so the researchers could watch when melatonin moved their clocks. A 0.5-milligram dose moved the clock earliest when it came in the afternoon, two to four hours before their own melatonin began to rise⁸8 Burgess et al., 2010. Taken at bedtime it did relatively little to the clock, and taken near the end of sleep it could push the clock later.

When the same study compared doses, each taken at its own best time, 0.5 milligrams moved the clock by about the same amount⁸ as 3 milligrams, with the smaller dose a little later in the day. The researchers suggest the smaller one wherever the sleepiness of 3 milligrams would get in the way. They also thought 3 milligrams somewhat more likely to bring a big shift, so a bigger dose isn't wasted every time. If you've drifted from 1 milligram to 5 and then to 10, each step up has likely changed little about what your clock hears. The hour you take it changes a great deal more.

What melatonin can do depends on what's keeping you up, and the evidence for each kind of trouble comes from different people. If your nights are short because life leaves too little room for them, between a late finish and an early alarm, melatonin can't add the hours that are missing, and getting through the day after a bad night may be more use to you for now.

One large trial asked whether melatonin works differently later in life. Researchers gave 791 adults with insomnia, aged 18 to 80, a prolonged-release 2-milligram tablet or a placeboplacebo A dummy treatment, such as a pill with nothing active in it. Studies compare a real treatment against one to see how much of the effect comes from the treatment itself. to take each night, and the people kept sleep diaries. Three weeks in, those aged 65 to 80 were falling asleep about nineteen minutes sooner, while on placebo the gain was under two minutes⁴4 Wade et al., 2010. Younger people with low melatonin levels gained nothing like it. Across everyone in the trial, the gains held through six months of nightly tablets. In Europe the tablet is now licensed for short-term insomnia in people 55 and over⁴.

Researchers don't read that trial the same way. The tablet's maker sponsored it, which is reason enough to want it confirmed. The American Academy of Sleep Medicine looked at trials of the same tablet in adults over 55 and judged its effects below clinical significance⁹9 Sateia et al., 2017, too weak to recommend. So what might you make of it, if you're older and lying awake? The tablet seems a reasonable thing to try for a set stretch, the way the UK prescribes it, usually for up to thirteen weeks¹⁶16 NHS, 2026d, with your own nights as the judge. That view is about the prolonged-release product that was studied, and what the trial found may not apply to the gummies on a supermarket shelf.

Later in life melatonin may also stay active for longer²¹⁶2 NCCIH, 2024 and leave you drowsy in the day, and for sleep problems in people living with dementia, the academy recommends against it²¹³13 Auger et al., 2015.

If you turn your own bottle over, the strength printed on it is probably 3 or 5 milligrams, which is what most US gummies tested in 2022 held in a serving¹⁷17 Cohen et al., 2023, often as two gummies. The doses that helped in studies were often far smaller. A dose of 0.5 milligrams moved the clock in healthy adults in the lab⁸8 Burgess et al., 2010, and it brought sleep earlier for adults with a diagnosed late clock¹²12 Sletten et al., 2018 in the Australian trial. For jet lagjet lag The tiredness and broken sleep that come from crossing time zones faster than your body clock can adjust to the new local time., doses up to 5 milligrams¹⁴14 Herxheimer & Petrie, 2002 helped airline passengers, crews and military personnel flying across five or more time zones.

So what the studies point to depends on your problem. For a late clock, the dose that helped was small and came an hour before the bedtime you want, with that bedtime kept, which suits a tablet that peaks in the blood about fifty minutes after you swallow it¹⁸18 Harpsøe et al., 2015. For jet lag, it goes near the new bedtime at your destination. For ordinary sleeplessness at lights-out the gain is small, and the studies are mixed on whether more adds anything. Trials that ran longer at higher doses found somewhat larger effects³3 Ferracioli-Oda et al., 2013 on how fast people fell asleep and how long they slept. Yet in a small study of thirty adults over 50, 0.3 milligrams left them spending at least as much of their time in bed asleep as 3 milligrams did⁹9 Sateia et al., 2017. That makes a smaller dose a fair experiment, one your own nights can judge.

In the US melatonin is sold as a dietary supplement, regulated less strictly than medicines²2 NCCIH, 2024, and what's inside can wander a long way from the label. When researchers bought twenty-five brands of melatonin gummies in the US and measured what each one held, they found twenty-two that didn't match their labels¹⁷17 Cohen et al., 2023. Some held less melatonin than the bottle said and some more than three times as much. One held no melatonin at all, but 31 milligrams of CBD.

An earlier team tested thirty-one supplements bought in Canada and found gaps wider still. A bottle there might hold 83 percent less than its label or 478 percent more²¹21 Erland & Saxena, 2017, and one batch of a product could differ from the next by up to 465 percent. About a quarter also contained serotonin, and paying more or choosing a known brand didn't protect anyone from any of it.

So the label in your hand can't tell you everything, though a few things help you choose. In the US, the USP Verified mark is the most reliable sign of dose and purity. The scheme is voluntary, and at the time of the 2022 count only four melatonin products had it¹³¹⁹13 Auger et al., 201519 AASM, 2022, all at 3 or 5 milligrams. Outside the US you may meet melatonin quite differently, because in several countries it's a prescription medicine². In the UK it's prescription-only¹⁶16 NHS, 2026d, mainly for short-term sleep problems in people 55 and over.

The morning after a tablet, some people wake groggy or with a headache, or feel tired, sick or irritable²¹⁶2 NCCIH, 202416 NHS, 2026d through the day. In trials, though, few people noticed much. When reviewers pooled thirty-seven trials, daytime sleepiness was what people reported most, and it came to fewer than two people in a hundred¹1 Besag et al., 2019; headache and dizziness turned up less often still. A few people had nightmaresnightmare A frightening dream that wakes you, usually from REM sleep later in the night, and that you can often remember clearly afterwards., agitation or mood swings, and for most, whatever they noticed faded within days or once they stopped. If you wake groggy after taking it, please don't drive or use machinery until the feeling has passed.

If you take warfarin or another blood thinner, or have epilepsy, please take melatonin only with your doctor's supervision; the concern comes from case reports²¹³2 NCCIH, 202413 Auger et al., 2015 rather than trials, and it's enough to make that conversation worth having. The antidepressant fluvoxamine keeps the body from clearing melatonin, so levels can climb to about seventeen times²²22 Härtter et al., 2000 what the dose would usually give. If you take it, your prescriber can help you decide. If you have diabetes, it's worth a word first too, since a single dose worsened glucose tolerance¹³ in a study of healthy women.

Taking melatonin alongside herbal remedies for sleep can make you very drowsy¹⁶16 NHS, 2026d, and alcohol or smoking can stop it working as well. In pregnancy and while breastfeeding, no trials have tested it²²³23 Vine et al., 2022 for sleep and the human studies there are have been few and small, so it's one to talk through with your midwife or doctor.

Your child has been lying awake night after night, and another parent swears by gummies. The jar beside the vitamins starts to look like an answer. The good evidence in children comes mostly from those with autism, ADHD or other neurodevelopmental conditions, under specialist care²2 NCCIH, 2024. In a thirteen-week trial of 125 children and teenagers, almost all of them autistic, whose sleep hadn't improved with behavioral help, prolonged-release melatonin added about thirty-two minutes of sleep a night²⁴24 Gringras et al., 2017 compared with placebo. The maker sponsored that trial, and what it found applies to children like those in it.

For children generally, the right dose and timing aren't known yet, and neither are the effects over long periods or whether a hormone supplement could affect puberty or other development, because the studies have been small and brief²¹³13 Auger et al., 2015. The American Academy of Sleep Medicine asks parents to talk to a pediatric health professional first¹⁹19 AASM, 2022, since many children's sleep troubles are better helped by changes to schedules, habits and routines. There's more on those in helping your child sleep.

If there's a jar of gummies in the house, what helps most is keeping it as you would any medicine, up high and out of children's reach¹⁹, with the lid closed, because small children do find it. Over the decade to 2021, calls to US poison centers about children swallowing melatonin rose 530 percent²⁵25 Lelak et al., 2022, and the biggest rise came among children 5 and under who found it at home and swallowed it by accident. Most of those children, about eighty-three in a hundred, had no symptoms at all.

If you're the parent of a teenager, the worry is a different one. Most of the children admitted to hospital²⁵ over those years were teenagers who had taken melatonin on purpose. If you fear yours might have, please get help without waiting.

The bottle in your palm this evening answers some kinds of trouble far better than others. If your trouble is a clock that runs late, or a flight across the world, melatonin is a signal worth timing well, in a small dose and at the right hour. If you lie awake for other reasons, it may be giving you a few minutes, and when you want something made for the long nights, CBT for insomnia is there. And whether you take it tonight or leave the bottle in the cupboard, your own melatonin will begin to rise as the light goes, as it has done every evening of your life.