Melatonin Dose: How Much to Take, When, and Is It Safe?

Short answer: For most adults, 0.5 to 3 mg of melatonin taken about 1 to 2 hours before your target bedtime is enough; higher doses don’t usually work better and cause more grogginess. Melatonin is best for shifting your body clock, such as for jet lag or a sleep schedule that runs late. It does little for long-term insomnia. Short-term use is generally safe for adults, but product doses are often inaccurate, and children should only take it with a doctor’s advice.

Melatonin is the hormone your brain releases in the evening as it gets dark. It doesn’t knock you out like a sleeping pill. Instead, it tells your body that night has arrived and helps set the timing of your sleep-wake cycle. In the US, melatonin is sold over the counter as a dietary supplement; in the UK and many other countries, it’s available only on prescription.

This guide explains what melatonin can and can’t do, how much to take, when to take it, side effects and interactions, and how to choose a product. For other sleep aids, see our guides to herbal teas for sleep and magnesium glycinate vs citrate.

Melatonin at a glance

What it does: Signals night-time and shifts the body clock
Typical adult dose: 0.5 to 3 mg
When to take it: 1 to 2 hours before target bedtime (for sleep); see timing below for jet lag
Best evidence: Jet lag and delayed sleep phase
Chronic insomnia: Not recommended as a treatment
Common side effects: Next-day drowsiness, headache, dizziness, nausea
Children: Only with a doctor’s advice

How melatonin works

Your body clock, based in a small region of the brain, runs on a roughly 24-hour cycle. In the evening, as light fades, the brain’s pineal gland starts releasing melatonin, which rises for a couple of hours before your usual bedtime and stays high through the night. Bright light, especially blue light from screens, suppresses it.

Taking melatonin as a supplement adds to this signal. Taken at the right time, it can shift your body clock earlier or later. That’s why it works best for timing problems, such as jet lag, rather than for people whose body clock is normal but who struggle to stay asleep.

What melatonin helps, and what it doesn’t

Each finding below carries an evidence label, explained in our editorial policy.

Jet lag Moderate evidence

Reviews suggest melatonin may reduce jet lag symptoms, especially after flying east across several time zones. It’s taken around the new local bedtime for a few days after arrival.

Delayed sleep phase Moderate evidence

Some people, often teenagers and young adults, have a body clock that runs late, so they can’t fall asleep until well after midnight. Low-dose melatonin taken earlier in the evening helps shift sleep earlier.

What the research actually found

What: A 2018 randomized trial of melatonin in people with delayed sleep-wake phase disorder
Size: 307 people
Dose and timing: Melatonin taken 1 hour before a set bedtime, alongside a fixed sleep schedule
Result: People fell asleep about 34 minutes earlier than with placebo
Limits: Effects depend on correct timing; the American Academy of Sleep Medicine’s recommendation for this use is weak

Insomnia Limited evidence

For ordinary long-term insomnia, melatonin’s effect is small: in pooled studies, people fell asleep only a few minutes faster. The US National Center for Complementary and Integrative Health (NCCIH) says there isn’t enough strong evidence to recommend it, and the American Academy of Sleep Medicine advises doctors not to use it for chronic insomnia. Cognitive behavioral therapy for insomnia (CBT-I) is the recommended first treatment.

Shift work Limited evidence

Studies in night-shift workers are small and inconclusive. Melatonin may help some people sleep during the day, but light exposure and schedule planning matter more.

Anxiety before surgery Moderate evidence

A review found melatonin reduced anxiety before surgery compared with placebo. This is given under medical supervision, not as a home remedy.

How much melatonin to take

More is not better. Your body naturally produces only small amounts, and studies show doses of 0.5 to 1 mg can be as effective as much higher doses for shifting the body clock. Many stores sell 5 mg and 10 mg tablets, which are more likely to leave you groggy the next morning.

Use	Typical adult dose	Notes
Falling asleep at a set time	0.5 to 3 mg	Start at the lowest dose
Jet lag	0.5 to 5 mg	At the new local bedtime for a few days
Delayed sleep phase	0.5 to 3 mg	Earlier in the evening; timing matters more than dose

Dose ranges are those commonly used in studies and clinical guidance for adults. Ask your doctor or pharmacist before starting, especially if you take other medicines.

Use melatonin for short periods, such as a few nights to a few weeks, and talk to your doctor if you feel you need it for longer. Long-term safety hasn’t been well studied.

When to take it

To fall asleep: take it 1 to 2 hours before the time you want to be asleep, not as you get into bed.
For jet lag when flying east: take it at the new local bedtime on arrival day and for 2 to 5 nights after.
For a body clock that runs late: a low dose taken several hours before your usual sleep time helps shift it earlier. Get bright light in the morning too.
Keep the lights low: bright light and screens in the evening work against melatonin.
Don’t drive or use machinery for at least 5 hours after taking it.

Tip: if you wake up groggy, lower the dose or take it earlier in the evening. Many people find 0.5 to 1 mg works as well as 5 mg with fewer side effects.

Side effects, interactions and who should avoid it

Short-term use appears safe for most adults. The most common side effects are next-day drowsiness, headache, dizziness and nausea. Some people have vivid dreams. Older adults may feel sleepy during the day.

Check with a doctor or pharmacist first if you

Take blood thinners such as warfarin; melatonin may affect clotting.
Take sedatives, sleeping pills or drink alcohol; the effects can add up.
Take fluvoxamine (an antidepressant), which can greatly raise melatonin levels.
Take diabetes, blood pressure, immune-suppressing or seizure medicines.
Have epilepsy, depression or dementia.
Are pregnant, trying to conceive or breastfeeding; there isn’t enough safety data.

Melatonin and children

Melatonin use in children has risen sharply, and so have accidental overdoses. US poison center reports of melatonin ingestion in children and teens rose from 8,337 in 2012 to 52,563 in 2021, an increase of about 530 percent, and the CDC estimated about 11,000 emergency visits from 2019 to 2022 for young children who took melatonin unsupervised. Most cases were mild, but some children needed hospital care.

A review of small studies found melatonin helped some children with sleep disorders fall asleep sooner, but the right doses and long-term effects in children are unclear. Gummies look and taste like candy, which raises the risk.

Give melatonin to a child only on a doctor’s advice.
Store it out of reach, like any medicine, in a child-resistant container.
Try bedtime routines, screen limits and consistent schedules first.

How to choose a melatonin product

Product accuracy is a real problem. A 2017 study of 31 melatonin supplements found most didn’t match their labeled dose, and about a quarter also contained serotonin. In a 2023 study of 25 melatonin gummies sold in the US, 22 were mislabeled: one contained no detectable melatonin, and the others contained 74 to 347 percent of the labeled amount.

Choose a low-dose product: 0.5 to 1 mg tablets, or tablets you can split, make it easier to use the smallest effective dose.
Look for a USP Verified seal, which confirms the product contains the labeled amount. USP has verified some melatonin products.
Prefer tablets over gummies, which have been the least accurate and are most tempting to children.
Avoid combination products with CBD or several herbs unless your doctor approves.
Immediate or extended release: standard tablets help you fall asleep; extended-release versions are meant for staying asleep, but evidence for them is limited.

Our guide on how to read a supplement label explains how to check doses and quality seals.

Better long-term options for sleep

If you’re reaching for melatonin most nights, these steps usually work better:

Keep the same wake-up time every day, including weekends.
Get daylight within an hour of waking, and dim lights in the evening.
Avoid caffeine after midday and limit alcohol.
Keep your bedroom cool, dark and quiet.
Ask your doctor about CBT-I, which is available through clinics and apps.

See a doctor if sleep problems last more than a few weeks, or if you snore loudly, stop breathing during sleep or feel very sleepy during the day.

Related on Pure Nutrition Facts: our chamomile vs valerian comparison, plus our ashwagandha guide.

Melatonin FAQ

How much melatonin should I take?

Most adults need only 0.5 to 3 mg. Start with the lowest dose. Higher doses rarely work better and cause more next-day grogginess.

How long before bed should I take melatonin?

About 1 to 2 hours before the time you want to fall asleep, in dim light.

Is it safe to take melatonin every night?

Short-term nightly use appears safe for most adults, but long-term safety isn’t well studied. If you need it for more than a few weeks, talk to your doctor.

Can you overdose on melatonin?

Large doses can cause drowsiness, headache, nausea and confusion. Serious harm is rare in adults, but children can be affected by accidental ingestion, so store it safely.

Does melatonin work for insomnia?

Only slightly. It helps most with timing problems such as jet lag. For long-term insomnia, CBT-I is the recommended first treatment.

Is melatonin legal in the UK?

In the UK, melatonin is a prescription-only medicine, so it can’t be sold as a supplement. Talk to your GP if you think it may help.

Melatonin: Dose, Timing and Safety