One in five school-aged children and preteens now takes melatonin to fall asleep, according to a new study published in JAMA Pediatrics.

The hormone is routinely given to an increasing number of children, according to a new study published on Nov. 13, which surveyed around 1,000 parents during the first half of 2023.

“We are not saying that melatonin is necessarily harmful to children,” lead author Lauren Hartstein, a postdoctoral fellow in the Sleep and Development Lab at the University of Colorado Boulder said, according to CU Boulder Today. “But much more research needs to be done before we can state with confidence that it is safe for kids to be taking long-term.”

As a dietary supplement, melatonin is not subject to full regulation by the Food and Drug Administration (FDA), the outlet noted.