Sleep gummies on the shelf at a Cambridge pharmacy Wednesday. (Photo: Marc Levy)

Research led by a Cambridge Health Alliance doctor has found that the amount of melatonin in gummies sold as sleep aids in the United States varies widely to up to three and a half times the labeled amount. For children, the actual amounts could far exceed levels reached in sleep if the gummies are taken as directed, found the study by Pieter Cohen, an internist at CHA’s Broadway Care Center in Somerville, found.

The research report published Tuesday in the Journal of the American Medical Association noted that calls to the U.S. network of poison centers for melatonin ingestion by children increased by 530 percent between 2012 and 2021, citing an article in the Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report. Though more than 80 percent of the children had no symptoms, 4,097 were hospitalized and two died. Over the 10 years, calls reporting melatonin ingestion by kids totaled 260,435.

“I had originally thought that melatonin was a very safe product, and usually it is,” Cohen said. But after seeing the CDC report last year “I decided to take a look at it.” Cohen, who said many of his patients are Brazilian immigrants, has specialized in studying harmful and often undisclosed substances in dietary supplements, which can be sold with little regulation in the United States. In 2009, he reported on two patients taking diet pills from Brazil laced with amphetamines; one tested positive for drugs in a screen for his job, the other suffered years of unexplained symptoms until the drugs were discovered. The same year, Cohen wrote an article in the New England Journal of Medicine titled “American Roulette – Contaminated Dietary Supplements” that urged Congress to restore FDA regulation of supplements.

Cohen

For the melatonin study, the first to examine melatonin levels in the supplements in the United States, Cohen and chemists at the University of Mississippi chose 25 brands of melatonin gummies that had most recently appeared on a dietary supplement database published by the National Institute of Health and which had the word “melatonin” on the label. Some products also said they contained cannabidiol, or CBD, which is found in marijuana.

The analysis showed that the gummies contained from 74 percent to 347 percent of the labeled amount of melatonin; all but two of the products had more melatonin than labeled. One brand of gummies contained no melatonin at all, only CBD. Only three of the products had melatonin levels within 10 percent of the label. The study didn’t identify the brands.

“It’s very common in my practice that many patients are taking melatonin thinking they can pick up any product on the shelf” and the label will be accurate, Cohen said. “We really need to look for products that have high-quality certification” such as a label from the National Science Foundation or U.S. Pharmacopeia, which test dietary supplements, he said. He also said he’s “encouraging patients to treat melatonin like an over-the-counter medication,” taking precautions to prevent children from obtaining it.

The JAMA report said doctors should warn patients that “pediatric use of melatonin gummies may result in ingestion of unpredictable amounts of melatonin and CBD.” At the Cambridge Health Alliance, “our leadership team will share the newly published research with our pediatrics staff and recommend they advise patients accordingly,” spokesperson David Cecere said.

Surveys show that more children under 18 are using or being given melatonin, though pediatricians say behavioral interventions should be the first step to improve sleep and the  hormone should generally be reserved for kids with disorders such as autism or attention deficit hyperactivity disorder. Most of the calls to poison control centers involved children who ingested melatonin accidentally.

More melatonin gummies for children are becoming available, according to an article published in 2021 in the Journal of Pediatric Pharmacology and Therapeutics. A search on Amazon for “melatonin gummies for children” produced 229 products.