In over-the-counter products, the actual content of either compound bore little resemblance to the labelled content, and neither is approved for promoting sleep in children.

Parents sometimes ask about using melatonin, usually in the form of chewable gummies, to aid sleep in their children. In the USA, melatonin gummies are sold over the counter (OTC) as a supplement (without Food and Drug Administration approval). Investigators assessed the melatonin content of 25 unique brands of OTC melatonin gummies, some of which also listed cannabidiol (CBD) as an ingredient. Melatonin and CBD content was measured by liquid chromatography.

The purported melatonin content in the gummies ranged from 1 mg to 10 mg, whereas the actual content ranged from 1.3 mg to 31.1 mg. The ratio of actual-to-labelled content ranged from 74% to 347%. Only three products had melatonin concentrations that were within 10% of the labelled amount. One product contained no melatonin but did contain 31 mg of CBD. Five products listed CBD as an ingredient, from 10 mg to 30 mg, and the ratio of actual-to-labelled content ranged from 104% to 118%.

Comment: Melatonin might have benefit in resetting circadian clocks but usually is used incorrectly, as if it promoted sleep directly. The dosages listed here could result in plasma concentrations in children far above what is thought to be helpful and could be harmful. Moreover, using CBD for sleep is not indicated. Parents should be advised that use of OTC gummies might result in unpredictable and potentially harmful levels of both compounds. A recent report suggests that unintentional melatonin ingestions by children are more common than one might expect and include at least two recent deaths (MMWR Morb Mortal Wkly Rep 2022; 71: 725-729).

Thomas L. Schwenk, MD, Professor Emeritus, Family and Community Medicine, University of Nevada School of Medicine, Reno, USA.

Cohen PA, et al. Quantity of melatonin and CBD in melatonin gummies sold in the US. JAMA 2023; 329: 1401-1402.

This summary is taken from the following Journal Watch titles: General Medicine, Pediatrics and Adolescent Medicine, Ambulatory Medicine, Neurology.