New study raises concerns over melatonin's impact on children's REM sleep and development

Research involving 684 children suggests that melatonin supplements may reduce REM sleep, prompting calls for caution and more regulated use among parents and healthcare professionals.

Melatonin has become a common bedtime fix for children, but a new study suggests it may not be the harmless shortcut many parents assume. Researchers looking at 684 children found that those who used the supplement spent less time in rapid eye movement, or REM, sleep, the stage most closely associated with dreaming, memory, learning and emotional development.

The finding matters because melatonin is widely viewed as a natural option rather than a medicine. But as the New York Post noted, the supplement is not reviewed by the U.S. Food and Drug Administration for safety or effectiveness before it reaches the market, and research has shown that the amount in some products can vary widely from what the label says. The FDA says manufacturers are responsible for ensuring dietary supplements are safe and properly labelled, while the agency can act only after products are on sale if they are adulterated or misbranded.

Dr Daniel Bigman, a child and adolescent psychiatry attending physician at Northwell’s Zucker Hillside Hospital and Cohen Children’s Medical Center, told the New York Post that melatonin can affect the body’s hormone balance and that families should be cautious about using it routinely. He said the new study does not prove melatonin caused the change in REM sleep, but argued that the possible link deserves attention because of the potential impact on developing brains.

Bigman said melatonin should generally be reserved for children diagnosed with a circadian rhythm or sleep-wake disorder, when timing and dosage can be carefully managed. For most families, he said the first step should be better sleep habits: a regular bedtime, a wind-down routine, limiting screens before bed and keeping the room dark and quiet. Mayo Clinic Health System, HealthyChildren.org and the Sleep Foundation all advise parents to speak with a paediatrician before giving melatonin and to treat it as a last resort rather than a first-line sleep aid.