Blog

Nov 20, 2023

Melatonin in over

Melatonin is a hormone associated with our sleep-wake cycles, with levels

Melatonin is a hormone associated with our sleep-wake cycles, with levels increasing as the sun goes down. For this reason, it's a popular sleep supplement for adults and children alike, perceived as being fairly harmless and supported by plenty of testimonials praising its positive effects.

If your child takes melatonin as a supplement, though, you’ll want to attend to some news about the melatonin content in over-the-counter gummies. According to a recent study published in the medical journal JAMA, the content of these gummies often exceeds what the label claims.

With almost a million children in the United States taking melatonin supplements as an aid for sleep or stress relief, these findings are relevant for 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 time, there were 4,097 children hospitalized, 287 admitted to intensive care and two deaths.

Many of the overdoses were related to the ineluctable attraction of sweetened gummies, leading to what's classified as "unintentional" ingestion. But the content of even one of those gummies may well exceed what it says on the label, by as much as 347%.

The JAMA authors used a government database to identify gummy-related melatonin products sold over the counter in the United States. They purchased 25 of the products and analyzed the content of melatonin and CBD in the gummies.

Two of the products contained less melatonin than the label stated. Twenty-two others had more than 100% of the claimed amount. One of these had 347% of the labeled melatonin content, containing 10.5 milligrams per gummy instead of the 3 milligrams given on the package.

Most products were described as containing 1, 3 or 5 milligrams of melatonin, but the measured content often exceeded these values by a third or more. Each of the five products that also listed CBD had a little higher CBD content than claimed. One gummy touted to contain 5 milligrams of melatonin contained no melatonin at all, but it did have more than the 30 milligrams of CBD stated on the package.

A caveat is that the researchers tested only one sample from each of the 25 brands, and they didn't test other forms of supplements, such as pills or capsules.

Other studies

This isn't the first study to find that what's touted on the tin isn't accurate. A 2017 study in Canada found an even wilder range of variability in melatonin content in supplement products. In that analysis, three of every four products didn't land 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 that the hormone will help with various problems, including sleep and stress, along with being able to "rest and restore muscles" and offer heartburn relief. The U.S. Food and Drug Administration has not approved melatonin as a treatment for any condition, and the agency does not assess over-the-counter supplements for safety or efficacy.

CBD is approved for three rare seizure-related disorders, but not for sleep or stress.

Reason for concern

Why be concerned about higher levels of melatonin than the package indicates? The study authors say that ingesting small amounts of melatonin, as low as 0.1 to 0.3 milligrams, can bump plasma concentrations into the range of normal for nighttime levels of the hormone. A child eating a single melatonin gummy at amounts identified in this study could be taking in a dose that's 40 times higher or more.

Another issue with hormones is that they tend to behave in ways that aren't completely intuitive. It's natural to think that a higher dose of something might yield a stronger effect, which might be a desirable outcome, to a point. But hormones are tricky chemicals that operate within a narrow range of "normal" and tend to be duds or damaging at levels above and below that range.

Melatonin also 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 drugs is not thoroughly examined.

Emily Willingham is a Marin science journalist, book author and biologist. You can find her on Twitter @ejwillinghamphd.

Sign up for email newsletters