Supplements
Melatonin: The Dose Most People Get Wrong
It is not a sedative. It is a clock signal. Here is the dose the research supports, the two situations where melatonin clearly works, and what testing found inside the bottles.
Melatonin is the sleep aid people reach for first. It is on every shelf, it comes in gummies, and it feels harmless in a way that a prescription sleeping pill does not.
Here is the part that gets lost. Melatonin is not a sedative. It is a timing signal. Your brain releases it in the evening as a message that night is coming, and taking it works best when you are using it to move that message earlier or later. That difference explains almost everything about when melatonin helps and when it does nothing.
What the research actually found
The most cited meta-analysis pooled 19 randomized trials covering 1,683 people with primary sleep problems. Melatonin helped, and the size of the help was small. People fell asleep about 7 minutes faster and slept about 8 minutes longer than on placebo. Sleep quality improved too, by a modest amount (Ferracioli-Oda, 2013).
A later meta-analysis in Sleep Medicine Reviews looked at the same question and landed in a similar place. The most convincing evidence was for falling asleep faster, especially in people whose body clock runs late, and for keeping sleep on schedule in people who are blind (Auld, 2017).
Seven minutes is real. It is also not what the marketing suggests you are buying.
Where melatonin clearly earns its keep
Jet lag is the standout. A Cochrane review of ten randomized trials found that melatonin taken close to bedtime at your destination reduced jet lag after flights crossing five or more time zones. Nine of the ten trials found a benefit, and the number needed to treat was 2, which is a strong result in any area of medicine (Herxheimer, 2002).
The other clear use is body clock disorders. The American Academy of Sleep Medicine endorses carefully timed melatonin for delayed sleep-wake phase disorder, which is the pattern where you cannot fall asleep until 2 a.m. no matter how tired you are, and for blind adults whose sleep drifts later every night (Auger, 2015).
Notice what both of those have in common. They are timing problems, and the melatonin is being used to move the clock.
Where the guidelines say to skip it
For ordinary chronic insomnia, the same academy reviewed the evidence and suggested that clinicians not use melatonin, for either falling asleep or staying asleep. That recommendation is graded weak, which means the evidence is thin rather than strongly negative, but it is still a recommendation against (Sateia, 2017).
This matters for anyone who is waking at 3 a.m. and staring at the ceiling. The evidence for melatonin is strongest for falling asleep in the first place. Staying asleep is a different problem, and melatonin is not really aimed at it.
The dose almost everyone gets wrong
Walk down the supplement aisle and the bottles say 5 mg and 10 mg. Your own body makes a fraction of that.
In a double blind trial, adults over 50 with poor sleep took 0.1 mg, 0.3 mg, or 3.0 mg of melatonin before bed. The physiologic dose of 0.3 mg restored sleep efficiency and brought their nighttime melatonin levels back into the normal range. The 3.0 mg dose also improved sleep, but it dropped body temperature and left melatonin elevated into the daylight hours (Zhdanova, 2001).
Melatonin still floating around at 10 a.m. is exactly what you do not want from a timing signal. That leftover grogginess people describe after a melatonin night is not imaginary.
The jet lag research points the same direction. Doses between 0.5 mg and 5 mg worked about equally well, and doses above 5 mg were no better (Herxheimer, 2002). More is not stronger here. It is just longer.
What is actually in the bottle
This is the part that should bother you most, because it is the one you cannot see.
Researchers analyzed 31 melatonin supplements sold over the counter. The actual melatonin content ranged from 83 percent below the label to 478 percent above it. More than 71 percent of the products missed their own label by more than 10 percent, and the amount varied between lots of the same product by as much as 465 percent. Eight of the supplements also contained serotonin, which is a controlled substance and has no business in a sleep gummy (Erland, 2017).
Gummies are no better. A 2023 analysis in JAMA of 25 melatonin gummy products found the actual melatonin ranged from 74 percent to 347 percent of what the label claimed. Only three of the 25 were within 10 percent of their stated dose (Cohen, 2023).
So when someone says a low dose did nothing and they had to work up to 10 mg, it is worth asking what they were actually taking.
Look for a third party quality seal on the bottle, from USP or NSF. It is not a guarantee, but it is the only signal you have that anyone checked.
Keep the gummies away from kids
Melatonin gummies taste like candy, and children have found them. Poison control centers logged 260,435 pediatric melatonin ingestions in the United States over ten years, and the yearly number rose 530 percent across that period. Hospitalizations and serious outcomes rose too, driven mostly by unintentional ingestions in children five and under (Lelak, 2022).
If there is melatonin in your house, it belongs in a cabinet, not the nightstand.
How to use it if you are going to
Start low. 0.3 mg to 1 mg is a reasonable place to begin, and you may need to cut a tablet to get there. Higher is not better and tends to leave you foggy.
Timing matters more than the dose. For jet lag, take it close to bedtime at your destination. For a body clock that runs late, a small dose a few hours before your target bedtime is the approach that has been studied. Taking melatonin at the wrong time of day can push your clock in the wrong direction and make things worse (Herxheimer, 2002).
Treat it as short term. Use it for a trip, a schedule change, or a stretch of shift work, not as a nightly habit you never revisit.
And be honest about what it will not fix. If the problem is a racing mind, night sweats, a partner who snores, or a schedule that leaves you six hours in bed, melatonin is aimed at a different target entirely.
The honest summary
Melatonin is a genuinely useful tool for jet lag and for a body clock that has drifted. For everyday insomnia it does a little, at a smaller dose than the bottle suggests, and the sleep guidelines do not recommend it. The supplement industry sells it as a sedative, which it is not, at doses several times higher than the research supports, in products that frequently do not match their own labels.
Used at a low dose, at the right time, for the right reason, it is a reasonable thing to try. It is just not the thing most people are buying it for.
When to see a doctor
Insomnia that lasts more than a few weeks, loud snoring or gasping at night, falling asleep during the day, or sleep problems that arrive with mood changes all deserve a real evaluation. Cognitive behavioral therapy for insomnia is the first line treatment for chronic insomnia and it outperforms every supplement on the shelf. Talk to your doctor before starting melatonin if you are pregnant, breastfeeding, taking blood thinners, or managing a seizure disorder.
References
- Ferracioli-Oda E, et al. Meta-analysis: melatonin for the treatment of primary sleep disorders. PLoS ONE. 2013. PMID: 23691095
- Auld F, et al. Evidence for the efficacy of melatonin in the treatment of primary adult sleep disorders. Sleep Medicine Reviews. 2017. PMID: 28648359
- Herxheimer A, Petrie KJ. Melatonin for the prevention and treatment of jet lag. Cochrane Database of Systematic Reviews. 2002. PMID: 12076414
- Auger RR, et al. Clinical practice guideline for the treatment of intrinsic circadian rhythm sleep-wake disorders. Journal of Clinical Sleep Medicine. 2015. PMID: 26414986
- Sateia MJ, et al. Clinical practice guideline for the pharmacologic treatment of chronic insomnia in adults. Journal of Clinical Sleep Medicine. 2017. PMID: 27998379
- Zhdanova IV, et al. Melatonin treatment for age-related insomnia. The Journal of Clinical Endocrinology and Metabolism. 2001. PMID: 11600532
- Erland LAE, Saxena PK. Melatonin natural health products and supplements: presence of serotonin and significant variability of melatonin content. Journal of Clinical Sleep Medicine. 2017. PMID: 27855744
- Cohen PA, et al. Quantity of melatonin and CBD in melatonin gummies sold in the US. JAMA. 2023. PMID: 37097362
- Lelak K, et al. Pediatric melatonin ingestions, United States, 2012-2021. MMWR Morbidity and Mortality Weekly Report. 2022. PMID: 35653284
Common questions
How much melatonin should I actually take?
You should take less melatonin than the bottle suggests. In a double blind trial in adults over 50 with poor sleep, a physiologic dose of 0.3 mg restored sleep efficiency and brought nighttime melatonin levels back to normal, while 3.0 mg also helped but lowered body temperature and left melatonin elevated into the next morning. In the jet lag research, doses between 0.5 mg and 5 mg worked about equally well and anything above 5 mg was no better. Starting at 0.3 mg to 1 mg is reasonable, and you may need to cut a tablet to get there.
Does melatonin help you stay asleep?
Staying asleep is the weakest part of the melatonin evidence. Across 19 randomized trials in 1,683 people, melatonin added about 8 minutes of total sleep time and shaved about 7 minutes off the time it took to fall asleep. The American Academy of Sleep Medicine reviewed the evidence and suggested clinicians not use melatonin for either sleep onset or sleep maintenance insomnia, a weak recommendation reflecting thin evidence. If you are waking at 3 a.m., melatonin is aimed at a different problem.
When does melatonin genuinely work?
For jet lag and for a body clock that has shifted. A Cochrane review of ten trials found melatonin taken close to bedtime at your destination reduced jet lag after flights crossing five or more time zones, with a number needed to treat of 2. Sleep medicine guidelines also endorse carefully timed melatonin for delayed sleep-wake phase disorder and for blind adults whose sleep drifts later each night. Timing is the active ingredient in both cases.
Is the amount on the melatonin label accurate?
The amount on the melatonin label is often not accurate. In an analysis of 31 over the counter melatonin supplements, actual content ranged from 83 percent below the label to 478 percent above it, more than 71 percent missed their own label by over 10 percent, and eight products contained serotonin. A 2023 JAMA analysis of 25 melatonin gummies found actual melatonin ranging from 74 percent to 347 percent of the labeled amount, with only three within 10 percent. Look for a USP or NSF third party seal.
