The guide

What's really in a bottle of melatonin

By GyroscopeUpdated November 14, 20269 sources

In the US, melatonin is sold as a dietary supplement, and the FDA doesn’t approve supplements or their labels before they go on sale. In a 2023 lab test of 25 US melatonin gummies, 22 missed their label. One had no melatonin at all, and the rest held anywhere from 74 to 347 percent of what the label said.

The number on the front is the company’s claim. With gummies you usually get more than it says, and sometimes a lot more.

Doesn’t the FDA check what’s in it?

Most people assume something sold next to cold medicine has been through the same checks. It hasn’t. The FDA’s own page says there are no provisions in the law for it to approve dietary supplements for safety before they reach the consumer, and that it generally doesn’t approve their claims or labels before use. The makers and sellers are responsible for meeting the rules, and the FDA mostly steps in after a product is on sale.

That’s a US rule. In several other countries melatonin is available only with a prescription and is treated as a drug. Outside the US, melatonin is often prescription only, so check your own country’s rules.

Meanwhile it’s become a big business. US melatonin sales went from $285 million in 2016 to $821 million in 2020.

A simple way to picture it

A melatonin label is like a bakery cookie marked “small”. You’ll get something roughly that size, and usually a bit bigger, but nobody weighed yours before it went in the bag.

For a cookie that’s fine. For a hormone, 0.5 mg and 1.7 mg stay in your blood for different lengths of the night.

What did the lab tests find?

The serotonin finding is the strange one. The 8 products held 1 to 75 micrograms of it, and the US National Center for Complementary and Integrative Health notes serotonin can have harmful effects even at fairly low levels.

What does that mean for your dose?

Take the label, then use the 2023 test’s numbers. The likely range is the 1.2 to 1.7 times that most gummies held. The full range is 0.74 to 3.47 times, leaving out the one gummy with none.

A 10 mg gummy at the high end is over 100 times a normal night’s peak. Your dose across the night draws a gummy as a band for this reason.

Why do gummies worry pediatricians?

Because small children get into them. US poison centers got 260,435 reports of children and teens swallowing melatonin from 2012 to 2021, and the yearly number rose 530 percent. In 2020 melatonin became the substance children most often swallowed in poison center reports.

A CDC report counted about 11,000 emergency visits from 2019 to 2022 for children 5 and under who got into melatonin on their own. Where the form was written down, gummies were the most common, at 47.3 percent of visits, and more than a third of the children had got into 10 or more pieces. Most children who swallow melatonin have no symptoms, 82.8 percent in the poison center data, but some end up in hospital.

Can you get it from food instead?

Not in any amount that compares with a tablet. A 2001 study at the University of Texas measured melatonin in tart cherries, which hold a lot of it compared with the levels in mammal blood. Montmorency cherries held about 13.46 nanograms per gram, and Balaton cherries about 2.06.

Do the arithmetic and a 0.3 mg tablet, about one normal night’s peak, matches the melatonin in roughly 49 pounds of Montmorency cherries. A 10 mg gummy matches about 1,640 pounds. A cup of cherries holds about 0.002 mg.

Tart cherry juice concentrate did raise melatonin in the urine and lengthen sleep in a 20-person trial, which is interesting. Are tart cherries a natural dose of melatonin? has the details.

How should you buy it?

1. Buy the smallest dose you can find. 0.3 mg is the same as 300 mcg, and 0.5 mg is 500 mcg. It’s easier to take two small tablets than to guess at a third of a big gummy.
2. Look for an outside lab’s test of each batch. A brand that pays an independent lab to check its products is giving you more than the law asks for.
3. If you use gummies, treat the label as a range. Start lower than you think you need.
4. Store it like medicine. High up, out of sight and closed.

Isn’t a big-name brand safe enough?