Melatonin is a hormone associated with our sleep-wake cycles, with levels increasing as the sun goes down. For this reason, it is a popular sleep supplement for both adults and children, considered to be fairly harmless and supported by numerous testimonials praising its positive effects.
However, if your child is taking melatonin as a supplement, you’ll want to read some news about the melatonin content in over-the-counter gummies. According to a recent study published in the medical journal JAMA, the contents of these gummies often exceed what is stated on the label.
With nearly a million children in the United States using melatonin supplements as an aid to sleep or stress relief, these findings are relevant to many families. One reason they matter, the study authors write, is the striking number of calls to poison control centers, which increased from 8,337 in 2012 to 52,563 in 2021. Along with 27,705 urgent or emergent care visits during this period, 4,097 children in hospitalized, 287 admitted to intensive care and two deaths.
Many of the overdoses were related to the inescapable appeal of sweetened gummies, leading to what is classified as “accidental” ingestion. But the content of even one of those gummies might exceed what’s on the label by 347%.
The JAMA authors used a government database to identify gummy-related melatonin products sold over the counter in the United States. They bought 25 of the products and analyzed the levels of melatonin and CBD in the gummies.
Two of the products contain less melatonin than stated on the label. Twenty-two others had more than 100% of the amount claimed. One had 347% of the labeled melatonin content, with 10.5 milligrams per gummy instead of the 3 milligrams listed on the package.
Most products were described as containing 1, 3 or 5 milligrams of melatonin, but the measured levels often exceeded these values by a third or more. Each of the five products that also listed CBD had a slightly higher CBD content than claimed. A gummy advertised as containing 5 milligrams of melatonin contained no melatonin at all, but it did contain more than the 30 milligrams of CBD listed on the package.
One caveat is that the researchers only tested one sample of each of the 25 brands, and they didn’t test any other forms of supplements, such as pills or capsules.
This isn’t the first study to show that what’s advertised on the tin isn’t accurate. A 2017 study in Canada found even greater variability in melatonin levels in supplement products. In that analysis, three of the four products did not come within 10% of what the label claimed for melatonin content. The Canadian group also found products contaminated with serotonin, which the authors of the JAMA study looked for but did not find in the gummies.
Package labels usually claim the hormone will help with various issues, including sleep and stress, along with the ability to “rest and repair muscles” and provide heartburn relief. The U.S. Food and Drug Administration has not approved melatonin as a treatment for any condition, and the agency does not evaluate over-the-counter supplements for safety or efficacy.
CBD is approved for three rare seizure-related conditions, but not for sleep or stress.
Cause for concern
Why worry about higher levels of melatonin than the packaging specifies? The study authors say that intake of small amounts of melatonin, as low as 0.1 to 0.3 milligrams, can raise plasma concentrations into the normal range for nighttime levels of the hormone. A child eating a single melatonin gummy in amounts identified in this study could ingest a dose 40 times higher or more.
Another problem with hormones is that they often behave in ways that are not entirely intuitive. It’s natural to think that a higher dose of something could have a stronger effect, which could be a desirable outcome to some degree. But hormones are tricky chemicals that operate within a narrow range of “normal” and tend to be duds or harmful at levels above and below that range.
Melatonin has other roles in the body besides setting a sleep cycle, including effects on reproductive hormones, and how it interacts with other over-the-counter or prescription medications is not thoroughly studied.
Emily Willingham is a Marin science journalist, book author, and biologist. You can find her on Twitter @ejwillinghamphd.