An observational study of 3,392 pediatric patients evaluated at Nationwide Children’s Hospital indicates that over-the-counter melatonin use is associated with a lower median percentage of rapid eye movement sleep compared to nonusers, though the clinical meaning of the small difference remains uncertain.
Melatonin has become a fixture in many household medicine cabinets. Parents frequently reach for the over-the-counter supplement to make bedtime easier, relying on its natural reputation to help children drift off. Yet melatonin has been used by up to 19% of pediatric patients in the past 30 days. Despite being the most commonly used sleep supplement for children, objective research into its effects on pediatric sleep architecture has remained surprisingly thin.
Most prior clinical trials have depended on actigraphy or parent-reported outcomes rather than polysomnography, which serves as the gold standard for measuring sleep stages. Multiple domains of sleep architecture, including slow-wave sleep and rapid eye movement sleep, are closely linked to pediatric growth, neurodevelopment, and emotional regulation. A cross-sectional analysis aimed to change that by examining objective sleep recordings.
Analyzing PSG Data From Nationwide Children’s Hospital
Researchers turned to a database containing 3,984 polysomnography studies from patients evaluated at Nationwide Children’s Hospital. After filtering out duplicate and technically inadequate recordings, the study analyzed data from 3,392 children. Within this cohort, 346 children were melatonin users with a mean age of 9.5 years. The group of melatonin users presented with a notably higher comorbidity burden and lower rates of obstructive sleep apnea compared to nonusers.
To account for these underlying health differences, researchers performed propensity score matching, pairing 342 melatonin users with an identical number of nonusers. The matched comparison revealed a distinct pattern in sleep stages.
“Melatonin users had a lower median percentage of REM sleep than matched nonusers (16.7% vs 19.0%).”
2minutemedicine, Observational Study Analysis
Beyond the difference observed in REM sleep, the analysis found no significant variations across 14 other polysomnography outcomes. Total sleep time, sleep efficiency, sleep onset latency, non-REM sleep stages, respiratory indices, arousal indices, periodic limb movements, and oxygen desaturation index all matched closely between the two groups.
Evaluating Underlying Factors and Clinical Meaning
Rapid eye movement sleep is widely recognized as the stage where most dreaming happens, playing a vital role for developing brains. While the recent findings highlight a small reduction in the share of the night spent in this stage, experts urge caution when interpreting the results.
Children who receive a melatonin prescription often carry psychiatric diagnoses or take additional medications for sleep. When researchers accounted for psychiatric diagnoses, the REM difference persisted but weakened. Once other sleep medications were factored into the analysis, the statistical significance disappeared entirely, pointing to underlying factors that may drive part of the association.
Dr. Alen Juginovic, a physician in the Department of Neurobiology at Harvard Medical School, compared overnight sleep recordings from 684 children to study how the supplement interacts with pediatric sleep architecture. When discussing the weight of the findings, Dr. Juginovic told Earth.com that the results should be viewed carefully.
Guidance for Parents and the Limits of Observational Data
The observational nature of the research means it cannot prove cause and effect. It remains unclear whether melatonin slightly reduces REM sleep or if children who are given the supplement already spend less of the night in that stage before starting use. Furthermore, single-night recordings cannot determine whether a child who spent a few minutes less in REM experienced any noticeable difference the following morning at school.
Federal health authorities note that melatonin is generally safe at ordinary doses for short-term use in most children. However, data regarding long-term use spanning years remains sparse.
What Remains Unresolved in Pediatric Sleep Research
Physicians stress that parents should avoid making abrupt adjustments based solely on observational data. Dr. Juginovic advised parents directly regarding how to handle ongoing supplement use.
“Parents should not stop or change their child’s melatonin solely because of this study. They should discuss the dose, timing, formulation, and continued need with their child’s physician rather than making changes independently.”
Dr. Alen Juginovic, Harvard Medical School
Definitive answers will likely require rigorous randomized, placebo-controlled trials. Researchers suggest that a crossover design—studying the exact same children with and without melatonin while tracking next-day cognition and behavior—would eliminate the confounding variables inherent in comparing different children with distinct underlying health conditions.
