How much

Is 10 mg of melatonin too much?

By GyroscopeUpdated November 14, 20268 sources

For almost everyone, yes. 10 mg is about 33 times the 0.3 mg that restored sleep in adults over 50, jet lag trials found nothing extra above 5 mg, and taken at 10:30pm it can stay above your own melatonin until somewhere between 3:45 and 6:45am.

10 mg sits on the shelf like any other strength, so it looks like a normal dose. People usually get there by stepping up. 3 mg didn’t seem to do much, then 5 didn’t, so 10 must be the one. But if 5 mg at lights out in a bright room did nothing, the problem was probably the hour or the light, and doubling the dose doesn’t fix either.

We’d drop to 1 mg, take it 1 to 3 hours before bed, switch to lamps once it’s in, and run two weeks of your own nights before deciding anything.

It’s like shouting an announcement that a whisper would carry, then hearing the echo until morning.

How much is 10 mg, really?

Your own night peak is about what 0.3 mg gives you. In a 1994 study at MIT, 0.1 and 0.3 mg gave peaks inside the normal range of a person’s own night, and the amount in the blood rose in step with the dose. On that scale 10 mg peaks about 33 times higher than your own melatonin ever does.

It also takes a long time to come down. A tablet loses half its melatonin about every 54 minutes, measured in 12 men in Copenhagen in 2016. From 33 times your own level, that’s about five halvings, which is how a 10:30pm dose is still above your own night’s peak at somewhere between 3:45 and 6:45am. In that study the same 10 mg tablet peaked more than 3 times higher in some men than in others.

If it’s a gummy, it may not even be 10 mg. In a 2023 lab test of 25 US gummy products, most held 1.2 to 1.7 times the label, so a 10 mg gummy is often more like 12 to 17 mg. The highest held 347 percent of its label, which on a 10 mg gummy would be about 35 mg.

What the trials found

In 2001, the MIT team gave 30 adults over 50 a placebo, 0.1, 0.3 and 3 mg, each for a week, 30 minutes before bed. 0.3 mg restored sleep in the poor sleepers and brought their blood melatonin back to a normal night level. 3 mg also helped, but it dropped their body temperature and kept melatonin raised into the daylight hours, and 10 mg is more than 3 times that dose.

For jet lag, a 2002 Cochrane review found doses from 0.5 to 5 mg worked about the same, with 5 mg getting people to sleep a little faster, and doses above 5 mg no more effective.

Across 37 trials with doses up to 12 mg a day, side effects were mostly mild, and daytime sleepiness was the most common. None were life threatening, but most of those trials lasted 4 weeks or less.

Tart cherries, for scale

Montmorency tart cherries hold about 13.46 nanograms of melatonin per gram. To get the 10 mg in one tablet from cherries, you’d have to eat about 1,640 pounds of them.

If you’ve taken 10 mg for months

You can come down. In a 2013 analysis of 19 trials, melatonin’s effect didn’t fade with continued use, so there’s no sign that people need more of it over time. Drop to 1 mg, move it earlier, keep your wake time fixed, and give it two weeks. If you take a prescription medicine every day, check with your prescriber before changing anything, and see the medicines answer.

The figure below draws one night with 0.5 mg and 10 mg side by side. Put your own dose and alarm into the night curve tool to see yours. Don’t drive after a dose.