Results highlight the need for improved quality control of melatonin supplements.
A new study suggests that the melatonin content of dietary supplements often varies widely from what is listed on the label.
Results show that melatonin content did not meet within a 10-percent margin of the label claim in more than 71 percent of supplements, with the actual content ranging from 83 percent less to 478 percent more than the concentration declared on the label. The study also found that lot-to-lot variability within a particular product varied by as much as 465 percent.
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“We found that some products have much more melatonin than is indicated on the label,” said study co-author Praveen K. Saxena, PhD, professor in the department of plant agriculture and the Gosling Research Institute for Plant Preservation at the University of Guelph in Ontario, Canada. “Our findings reveal that further research is needed to clearly establish the stability and appropriate storage conditions to ensure safety, efficacy, and quality of melatonin products.”
Study results are published in the Feb. 15 issue of the Journal of Clinical Sleep Medicine.