New research published in JAMA Network found that melatonin gummies may contain far more of the dietary sleep aid supplement than what is indicated on the label. Researchers from Cambridge Health Alliance and the University of Mississippi analyzed 25 different melatonin gummies and found that 22 contained a greater amount of melatonin than what was stated on the label. One product contained only three-quarters of the amount advertised on the label, another contained 347 percent more than what was listed, and one product contained no detectable melatonin.

These concerns come on the heels of a 2022 report by the U.S. Centers for Disease Control and Prevention, which found a 530 percent increase in the number of accidental pediatric ingestions of melatonin reported to U.S. poison control centers over the last decade, resulting in 27,795 emergency department and clinic visits, 4,097 hospitalizations, 287 intensive care unit admissions and two deaths. Most ingestions were unintentional (94.3 percent). Among those children with reported symptoms from accidental melatonin ingestion, most involved the gastrointestinal, cardiovascular or central nervous systems.