Standard melatonin doses range from 0.5 mg to 10 mg per tablet, and the right amount depends on your age, sensitivity, and what your body needs

Most people take between 1 mg and 5 mg of melatonin at bedtime. A typical tablet contains 3 mg, 5 mg, or 10 mg. Start with the lowest dose that might work for you — often 0.5 mg to 1 mg — because melatonin affects people very differently. Some people fall asleep on half a tablet; others need more. There is no universal "correct" dose, and taking more does not necessarily work better.

Melatonin is not a sedative. It signals your body that it is time to sleep by mimicking the hormone your brain naturally makes when the sun sets. It works best when taken 30 minutes to two hours before bed, and it works better for some sleep problems than others — particularly for jet lag and shift work, less reliably for insomnia caused by stress or anxiety.

Key Takeaways

  • Start with 0.5 mg to 1 mg and increase only if that dose does not help you fall asleep within a few nights.
  • Most people who find melatonin helpful take between 1 mg and 5 mg, though some tablets contain 10 mg or more.
  • Taking a larger dose does not make melatonin work faster or better; it may cause grogginess the next morning instead.
  • Melatonin works best for jet lag and shift work sleep problems, and less reliably for chronic insomnia.
  • Children, older adults, and people taking other medications should talk to a doctor before using melatonin regularly.

Why starting low matters more than the tablet size

A 10 mg tablet does not mean you should take a 10 mg dose. Many people take melatonin at doses far higher than necessary, which can cause next-day drowsiness, headaches, or vivid dreams without improving sleep. The lowest effective dose is always the best choice.

Your body's sensitivity to melatonin depends on age, metabolism, and whether you have taken it before. A first-time user often responds to 0.5 mg or 1 mg. If you have been taking melatonin for weeks and it stops working, the problem is usually not that you need more — it is that your body has adjusted to the dose. Taking a break for a few days often restores the effect better than increasing the amount.

If you buy a 5 mg or 10 mg tablet and want to start lower, you can cut it in half or quarters. Melatonin tablets are stable when split, though extended-release formulas (which dissolve slowly over time) work less predictably when broken.

Dosage by age and situation

Children under 18 should not take melatonin without a doctor's recommendation. A child's sleep problems usually have other causes — screen time before bed, irregular sleep schedules, anxiety, or a medical condition — that melatonin will not fix. If a child's doctor does recommend it, the dose is typically much lower than adult doses, often 0.5 mg or less.

Adults aged 18 to 65 typically start with 1 mg to 3 mg. Older adults (65 and up) often respond to lower doses because their bodies process melatonin more slowly. A 1 mg dose is often enough, and doses above 5 mg increase the risk of next-day grogginess.

For jet lag, taking melatonin at the destination's bedtime for a few nights can help reset your sleep cycle. Doses of 0.5 mg to 5 mg work for this purpose; the timing matters more than the amount. For shift work, the same principle applies — take it before your sleep period, whatever time that is.

When to take melatonin and how long it lasts

Take melatonin 30 minutes to two hours before you want to fall asleep. It reaches peak levels in your blood within 30 to 60 minutes. The effect typically lasts four to eight hours, which is why taking it at bedtime works for most people — it keeps your sleep signal active through the night.

Extended-release melatonin dissolves slowly and may keep working longer, which can help if you wake in the middle of the night. Regular (when ready-release) melatonin works faster but wears off sooner. If you wake early and cannot fall back asleep, an extended-release formula might help, though the evidence is mixed.

Melatonin leaves your system relatively quickly. It does not build up in your body the way some sleep medications do, so you do not need to worry about accumulation if you take it nightly for a while. However, using it every night for months may reduce its effectiveness over time.

Melatonin and other medications or health conditions

Melatonin can interact with blood thinners, diabetes medications, immunosuppressants, and some seizure medications. If you take any regular medication, ask your doctor or pharmacist whether melatonin is safe to combine with it. Do not assume that because melatonin is sold over the counter it is safe with everything else you take.

People with autoimmune conditions, depression, bipolar disorder, or a history of blood clots should talk to a doctor before using melatonin. Melatonin affects immune function and mood regulation, and it can increase clotting risk in some people. Pregnancy and breastfeeding are also reasons to check with a doctor first, because melatonin's effects on a developing baby or nursing infant are not well understood.

Signs you are taking too much

If you wake up groggy, have a headache, feel nauseated, or have unusually vivid or disturbing dreams, you may be taking more melatonin than you need. Cut the dose in half and see whether the side effects stop. Most people tolerate melatonin well, but these symptoms are common when the dose is too high.

Daytime drowsiness the next day is a sign to reduce your dose or take it earlier in the evening. Some people also report mood changes, dizziness, or stomach upset at higher doses. These effects are not dangerous, but they mean the dose is not right for you.

What to do if melatonin is not working

If you have taken the same dose for two weeks and sleep has not improved, melatonin may not be the right tool for your sleep problem. Melatonin works best for circadian rhythm problems — jet lag, shift work, delayed sleep phase — and less reliably for insomnia caused by stress, pain, or racing thoughts.

Before increasing the dose, try adjusting when you take it. Taking melatonin earlier or later can sometimes make a difference. You can also try a break of a few days to reset your body's response, then start again at a lower dose.

If melatonin does not help after a fair trial, talk to a doctor about your sleep. Sleep problems often have fixable causes — caffeine timing, light exposure, room temperature, or an underlying condition — that melatonin will not address. A doctor can help identify what is actually keeping you awake.

Frequently Asked Questions

Can I take melatonin every night?

Yes, melatonin is generally safe for nightly use over weeks or months. It does not create physical dependence the way some sleep medications do. However, your body may become less responsive to it over time, so taking occasional breaks can help maintain its effect. If you find yourself needing melatonin every night to sleep, talk to a doctor about what might be causing the sleep problem.

What happens if I take too much melatonin?

Taking a very high dose — 20 mg or more — is unlikely to cause serious harm, but it increases the risk of next-day grogginess, headaches, and vivid dreams. There is no antidote; the melatonin will straightforward wear off over a few hours. If you accidentally take a much larger dose than intended, expect to feel drowsy the next day and reduce your dose going forward.

Is liquid melatonin better than tablets?

Liquid melatonin works the same way as tablets, but it may be easier to dose precisely — you can measure out 0.5 mg or 1 mg drops instead of cutting a tablet. Liquid also absorbs slightly faster. The choice comes down to convenience and cost; both forms are effective.

Can I combine melatonin with other sleep aids?

Do not combine melatonin with prescription sleep medications, alcohol, or over-the-counter sleep aids without asking a doctor first. Melatonin can be combined with some non-medication approaches — like keeping your bedroom cool and dark — but mixing it with other drugs increases the risk of side effects and dangerous interactions.

Does melatonin work better on an empty stomach?

Melatonin absorbs slightly faster on an empty stomach, but food does not significantly reduce its effect. If taking melatonin with food helps you remember to take it, that is fine. If you have a sensitive stomach, taking it with a light snack may reduce any nausea.