Melatonin use on the rise in young children, despite lack of long-term outcomes research

Melatonin use in children 6 years old and younger is rising globally, but there is little data on its effectiveness or long-term health effects in kids with typical neurological development, according to a literature review led by Chelsea Kracht, Ph.D., assistant professor in the Department of Internal Medicine at the University of Kansas Medical Center, and published in JAMA Network Open.

Kracht’s research typically focuses on caregiver and child health, including promoting an adequate balance of what are known as “24-hour movement behaviors,” which include physical activity, sedentary behavior and sleep. She became interested in melatonin during research interviews she conducted with children, when a number of children said they took melatonin gummies to help them sleep. “This had never come up in the literature,” Kracht said. “Most of the time when we think about sleep, it's a bedtime routine.”

Melatonin, a hormone that helps regulate the body’s sleep-wake cycle, has become a popular sleep aid around the world, for children as well as adults.

“Sleep is a huge area of interest and concern for both children and adults, and families are turning to melatonin, a supplement that is affordable, accessible and assumed to be safe, more and more often,” said Rob Breeden, M.D., clinical assistant professor at KU Medical Center and a pediatrician with The University of Kansas Health System.

Sold over the counter in the United States as a dietary supplement, including as gummies in flavors such as cherry and grape, melatonin has also become the leading cause of unsupervised ingestion of medication and overdose for children under the age of 5 who are treated in U.S. emergency rooms. Yet studies about melatonin usage and health effects on younger children are limited. Kracht wanted to learn more.

“Melatonin is used in adults and sometimes in older kids, but kids below age 5 — these are not small adults, they're kids,” said Kracht. “And so we said, what does the literature say for below (age) 5? Should kids be using it? We wanted to see what the long-term outcomes were. Is it effective? Is it safe?”

To answer these questions, Kracht and her colleagues conducted a systematic review of 19 melatonin studies. Their review did show that young kids with autism spectrum disorder, for whom supplements are sometimes recommended because of sleep problems linked to low production of melatonin, fell asleep faster with melatonin treatment. But no studies examined effectiveness in kids in this age group with typical development, and none measured outcomes in those who took it longer than two years.

Meanwhile, the studies showed that the use of melatonin as a sleep aid for children younger than age 6 has increased around the world over the last 20 years, and especially over the last decade. In countries where melatonin requires a prescription, these prescriptions have increased by as much as 500% in some areas. Moreover, the studies showed increases in extended use of melatonin, with young children getting refills two and three years after the initial prescription. 

In countries such as the United States that classify melatonin as a dietary supplement and do not require a prescription, there were increases in overdoses, especially since 2018.

The possible culprits for the increase, Kracht said, include increased treatment at home during the COVID-19 pandemic due to large amounts of screen time, which delays the onset of sleep; increases in child-friendly gummy products; and potentially higher use of melatonin by parents, whose supplements might be consumed by their children.

Breeden, who is a co-author on the study, noted that the most common outcome of kids ingesting too much melatonin is excessive sleepiness and fatigue, but it can also cause gastrointestinal problems, dizziness and low blood pressure, and in extreme cases, respiratory failure and death.

“There is a common misconception that a product is safe because it is available on the shelf at the store,” said Breeden. “As we see with melatonin, that is not true, and a seemingly harmless berry-flavored gummy can bring serious harm to our patients, particularly young children.”

The researchers call for reducing melatonin use in young children with typical development by improving pediatrician and parental support of good behavioral sleep practices, including reducing screen time at night; increasing parental education about melatonin; assessing supplement usage in children and parents; and instituting long-term medical follow-up for children who use melatonin for an extended time.

“Before we start a medication, it is important to consider a child’s daily routine and recognize areas that are counterproductive to healthy sleep. How much screen time are we getting? How much caffeine? Is exercise happening daily? Are we eating nutritious meals? And do we have a predictable routine before bed?” Breeden said. “With good and consistent sleep hygiene, many sleep issues can be overcome without medication.”