How much melatonin is too much?

For most adults, 1 to 2 extra tablets is unlikely to harm you, but the NHS lists 10 mg as a maximum prescribed dose for longer-term sleep problems and advises contacting a nurse or doctor if you feel unwell after taking more than your dose.

That said, melatonin is not a volume knob you can simply turn up. The right amount is the smallest one that helps you settle, and that number is different for everyone.

How much melatonin is too much

For sleep, more is not better. A 2016 review in Clinical Drug Investigation found that short-term melatonin use is safe even at high doses, with only mild effects like dizziness, headache, nausea and sleepiness reported. The same review notes that long-term treatment in clinical studies caused only mild effects comparable to placebo. Even so, the NHS caps prescribed doses for longer-term adult sleep problems at 10 mg a day, and short-term insomnia usually starts at one 2 mg slow-release tablet taken 1 to 2 hours before bed. If you are already taking a high dose and feeling groggy, the simplest fix is usually to step down, not up. We are not doctors, but we can read a label.

Can you overdose on melatonin?

Serious overdose is rare, but it happens. A 2024 case report in Sleep Medicine: X describes a teenager who took 900 mg of melatonin along with alprazolam and needed emergency care; he was extremely drowsy and minimally responsive, though his vital signs stayed stable and he recovered after supportive treatment. A 2023 case report in The American Journal of Forensic Medicine and Pathology describes a death involving combined diphenhydramine and melatonin toxicity. Melatonin alone has low toxicity, but mixing it with other sedatives can be dangerous. If you or someone else has taken a large amount and feels unwell, call a poison centre or emergency services.

What does 10 mg of melatonin feel like?

Most people do not need 10 mg. The NHS says the maximum prescribed dose for longer-term sleep problems is 10 mg once daily, and that dose is reached gradually under medical supervision. Common side effects at higher doses include daytime sleepiness, headache, stomach ache, nausea, dizziness, dry mouth, dry or itchy skin, pains in the arms or legs, and strange dreams or night sweats, according to NHS guidance on side effects. Serious side effects are rare and happen to fewer than 1 in 1,000 people. If you feel drugged rather than drowsy, that is your cue to talk to a pharmacist or doctor.

Melatonin dose for jet lag

Jet lag has its own rules. The usual adult dose is one 3 mg standard tablet, and you can increase to two tablets, which is 6 mg, if needed, per NHS guidance. Take it at your normal bedtime at your destination, but not before 8pm or after 4am, and use it for up to 5 days. Do not stack extra doses to catch up. If you forget a dose, skip it and start again the next night.

Can you take melatonin every night?

Melatonin is usually recommended for short-term sleep problems. The NHS says short-term insomnia is often treated for 1 to 4 weeks, and sometimes up to 13 weeks. A NHS Sussex patient leaflet suggests taking melatonin for the shortest time possible, such as a few months or up to a year, and recommends treatment holidays of 7 to 14 days at least once a year so you can see whether it is still helping. Many people find they sleep fine after a break, especially if they keep good sleep hygiene.

Who should not take melatonin

The 2016 review notes that long-term safety in children and adolescents still needs more research, and because human studies are lacking, pregnant and breastfeeding women should not take exogenous melatonin. If you fall into either group, talk to a doctor before using it.

What helps sleep besides melatonin?

Sleep hygiene does the heavy lifting. That means regular bed and wake times, a dark, quiet and cool bedroom, no caffeine or alcohol in the evening, and a relaxing wind-down routine. Some people also add calming herbs; if your bathroom shelf is already crowded, we get it. If you are curious, we have a piece on whether chamomile actually helps you sleep and another on ashwagandha for stress. If you want a gentle nightly blend, we happen to make Berth: valerian 150 mg, chamomile, GABA, L-tryptophan, lemon balm and passion flower at 100 mg each, plus 2 mg of melatonin, two capsules before bed.

Melatonin dose guide

Here is a quick look at the doses the NHS describes for adults.

Form	Typical amount	Why it matters	What to do
Standard tablet	3 mg	Usual dose for jet lag	Take at destination bedtime, up to 5 days
Slow-release tablet	2 mg	Usual starting dose for short-term insomnia	Take 1 to 2 hours before bed, with food
Slow-release tablets	Up to 10 mg	Maximum prescribed dose for longer-term sleep problems	Only under a doctor's supervision
Extra tablets	1 to 2 more than prescribed	Unlikely to harm you	Contact a nurse or doctor if you feel unwell

FAQ

Is 10 mg of melatonin too much? The NHS lists 10 mg as the maximum prescribed dose for longer-term sleep problems in adults, but it is reached gradually and only under medical supervision. If you are taking that much without a clinician's guidance, it is worth a conversation with a pharmacist or doctor.

Can you overdose on melatonin? Serious overdose is rare. A 2024 case report describes a teenager who took 900 mg and needed emergency care, and a 2023 case report describes a death involving melatonin combined with diphenhydramine. Melatonin alone has low toxicity, but mixing it with other sedatives is risky. If someone has taken a large amount and feels unwell, call emergency services or a poison centre.

Can I take melatonin with alcohol? No. The NHS advises against drinking alcohol with melatonin because the combination can make you sleep very deeply, breathe improperly, and have difficulty waking up, as explained in common questions about melatonin.

How long does melatonin take to work? Melatonin takes around 1 to 2 hours to work, according to NHS guidance.

Will I get addicted to melatonin? If you take it as prescribed, you are unlikely to become addicted. If you have been taking it for a long time and want to stop, ask a doctor or pharmacist about coming off it gradually, as noted in NHS common questions.

Sources

• The Safety of Melatonin in Humans (Clinical drug investigation, 2016)
• Case report on melatonin overdose: Cause and concern (Sleep medicine: X, 2024)
• Case Report of Lethal Concentrations of the Over-the-Counter Sleep Aids Diphenhydramine and Melatonin (The American journal of forensic medicine and pathology, 2023)
• How and when to take melatonin (www.nhs.uk)
• Common questions about melatonin (www.nhs.uk)
• Side effects of melatonin (www.nhs.uk)
• Melatonin patient information leaflet (int.sussex.ics.nhs.uk)

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.