How much

How much melatonin is too much?

By GyroscopeUpdated November 14, 20268 sources

For an adult, anything over 5 mg buys nothing extra in the trials, and doses up to 12 mg a day caused mostly mild side effects, mainly daytime sleepiness. If a child swallowed some, call Poison Control at 1-800-222-1222, and call 911 if they collapse, have a seizure, have trouble breathing or can’t be woken.

People search “melatonin overdose” after a handful of gummies, a second tablet at 3am, or a child getting into the jar. Most adults who take too much end up with a groggy morning. Children are a different case, and the jar belongs up high and out of sight.

For adults we’d stay at 5 mg or under, and most nights 0.5 to 1 mg. Past 5 mg, more adds grogginess and no extra sleep, because a bigger dose stays in your blood longer.

Think of the volume on a car radio. Past a certain point, turning it up makes the song no clearer and the drive harder.

Can you overdose on melatonin?

In adults, the trials haven’t found a dangerous dose, but they haven’t tested big ones for long either. A 2019 review of 37 trials, with daily doses from 0.15 to 12 mg, found the most common side effects were daytime sleepiness (1.66 percent of people), headache (0.74), dizziness (0.74) and a drop in body temperature (0.62). None were life threatening, and most went away on their own within a few days or once people stopped. Most of those trials lasted 4 weeks or less, so nobody knows much about years of high doses.

The benefit tops out early. In a 2002 Cochrane review of jet lag trials, 0.5 to 5 mg worked about the same, and doses above 5 mg were no more effective. In adults over 50, 3 mg kept melatonin raised into the daylight hours, while 0.3 mg was enough to restore sleep.

If it’s a gummy, the label may be off. In a 2023 test of 25 US gummy products, the real dose ran from 74 to 347 percent of the label, so two gummies of “5 mg” could be over 30 mg.

When a child swallows melatonin

US poison centers got 260,435 reports of children and teens swallowing melatonin from 2012 to 2021, and the yearly number rose 530 percent. 94 percent were accidents, 84 percent were children 5 or younger, and 83 percent had no symptoms at all. A small number got seriously ill. 287 needed intensive care over the 10 years, and most hospital stays involved teenagers who took it on purpose.

Call Poison Control at 1-800-222-1222 right away, before any symptoms show. It’s free, confidential and open 24 hours. What to do if your child ate melatonin gummies walks through the call.

The figure below shows how far above your own night 10 mg goes compared with 0.5 mg. Don’t drive after a dose.