Does Melatonin Work? What the Evidence Says (and How Much Is Really in Your Gummies)
Melatonin helps a little, for some problems. In studies of people with insomnia, it helped them fall asleep on average only about 7 minutes faster than a placebo. It’s more useful for problems with the timing of the body clock, such as jet lag. And because it’s sold as a dietary supplement in the US, doses vary: in a 2023 study, 22 of 25 melatonin gummy brands didn’t contain the amount on the label.
Key facts
- Melatonin is a hormone your body makes in the evening to signal night-time. It isn’t a sedative like a sleeping pill.
- Across trials, it reduced the time to fall asleep by about 7.5 minutes and increased total sleep by about 13 minutes.
- In 2023, researchers found melatonin gummies contained 74% to 347% of the labelled amount.
- US poison centre reports of children swallowing melatonin rose 530% from 2012 to 2021.
How melatonin works
Your brain’s pineal gland releases melatonin as it gets dark, which helps tell your body it’s night. Melatonin supplements work mainly by nudging the timing of your body clock, rather than knocking you out. That’s why they’re more promising for jet lag or for people whose body clock runs late than for general insomnia.
Does it help with insomnia?
Not by much. A review of trials, mostly small and short, found melatonin shortened the time to fall asleep by about 7.5 minutes and added about 13 minutes of sleep compared with a placebo. The American Academy of Sleep Medicine’s 2017 guideline suggests doctors not use melatonin to treat chronic insomnia, because the benefit is small. For long-term insomnia, the recommended first treatment is cognitive behavioural therapy for insomnia (CBT-I).
Jet lag and the body clock
Melatonin is more useful when your body clock is out of step with local time. The CDC’s travel guidance says that doses of 0.5 to 1 mg are often enough for jet lag and that doses above 5 mg aren’t recommended. Timing matters, because taking it at the wrong time of day can shift your body clock in the wrong direction, so ask a pharmacist or travel clinic for advice on your trip. Our jet lag planner gives a plan for light and sleep times.
What’s really in melatonin gummies
In 2023, Pieter Cohen and colleagues tested 25 brands of melatonin gummies sold in the US and published the results in JAMA:
| Finding | Result |
|---|---|
| Products with the wrong amount | 22 of 25 (88%) |
| Within 10% of the label | 3 of 25 |
| Actual melatonin vs label | 74% to 347% |
| Melatonin per serving | 1.3 mg to 13.1 mg |
| Products with no melatonin at all | 1 (it contained only CBD) |
In the US, melatonin is a dietary supplement, so it isn’t checked by the FDA before it goes on sale. In Canada, the UK, Australia and much of Europe, it’s regulated as a medicine or a licensed natural health product, and in the UK it’s prescription-only.
Melatonin and children
A CDC report found that calls to US poison centres about children swallowing melatonin rose 530%, from 8,337 in 2012 to 52,563 in 2021. Most involved children aged 5 or under, and almost all were accidental. Over the decade, 4,097 children were hospitalised. Keep melatonin, especially gummies, out of children’s reach, and talk to a doctor before giving it to a child.
If you want to try it
- Talk to a doctor or pharmacist first, especially if you take other medicines, are pregnant, or want to give it to a child.
- Start with a low dose. More isn’t necessarily better.
- Look for a product with a third-party quality seal, such as USP Verified.
- Don’t use it every night as a long-term fix for poor sleep. Fix the basics first: a regular schedule, less caffeine and a dark, cool bedroom. The sleep calculator can help you set a realistic bedtime.
Sources
- Lelak K et al. Pediatric melatonin ingestions, United States, 2012–2021. CDC MMWR, 2022
- American Family Physician: Melatonin for insomnia in adults, 2021
- Sateia MJ et al. Clinical practice guideline for the pharmacologic treatment of chronic insomnia in adults. AASM, 2017
- Cohen PA et al. Quantity of melatonin and CBD in melatonin gummies sold in the US. JAMA, 2023. Summary: MDedge
- CDC Yellow Book: Jet lag disorder
Frequently asked questions
How long before bed should I take melatonin?
It depends on why you’re taking it. For jet lag, the CDC describes taking it in the early evening by your body clock. Ask a pharmacist for advice on your situation.
Is it safe to take melatonin every night?
Short-term use appears to be safe for most adults, but there is less evidence on long-term use. Talk to a doctor if you need help sleeping most nights.
Can melatonin make you groggy?
Yes, some people feel drowsy the next morning, especially at higher doses.
