Labdoor analyzed 25 best-selling melatonin supplements in the United States for melatonin and heavy metal (arsenic, cadmium, lead, mercury) contamination.
Approximately half of the products tested (12 of 25) measured melatonin levels within 10% of their label claims. 6 products deviated from their claims for melatonin by at least 25%. 2 of those products recorded 40% or more melatonin than their label claims, and 1 product had less than 1% of its label claim for melatonin.
Measured melatonin content ranged from being less than 1% of the label claim to being 77% more than a product’s label claim, with products deviating off their claim by an average of 5.6%.
More than half of the products (14 of 25) contained less melatonin than what their labels claimed. Ten products recorded melatonin content above their label claims, with 9 of these products exceeding their label claims by at least 10% and six products exceeded their claims by at least 20%. Nature Made Adult Melatonin Gummies were found to have the exact amounts of melatonin they claimed on their label.
All of the tested products passed heavy metal screens for arsenic, cadmium, lead, and mercury.