A study by the Journal of the American Medical Association published in April 2023 found that only 12% of the 30 preparations analyzed contained quantities of melatonin that were within ±10% of the declared dosage. Some supplements contained up to 347% of the declared quantity. Melatonin is an active pharmaceutical ingredient in Europe, while the U.S. in 2022 considered the substance for inclusion in pharmacy compounding. A previous study from 2022 also concluded that consuming unregulated melatonin products 'as directed' could expose children to between 40 and 130 times higher quantities of melatonin than indicated.Cohen PA, Avula B, Wang Y, Katragunta K, Khan I. (April 2023) "Quantity of Melatonin and CBD in Melatonin Gummies Sold in the US" JAMA. 329 (16): 1401–1402. doi:10.1001/jama.2023.2296. PMID 37097362
