The amount of melatonin in dietary supplements promoted to help regulate sleep and wake cycles varies dramatically from 83 percent less than the concentration declared on the product’s label to 478 percent more, with lot-to-lot variations of as much as 465 percent, according to a new study published in the Journal of Clinical Sleep Medicine.
“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.”
Melatonin is a natural hormone widely marketed online and at retail stores. Use of the sleep aid has more than doubled in recent years, according to the National Center for Health Statistics of the National Institutes of Health, with an estimated 3.065 million adults having used the supplement at least once in the past 30 days.
Though generally considered safe, melatonin has been linked to side effects including headache, short-term feelings of depression, daytime sleepiness, dizziness, stomach cramps and irritability. Adverse events are more likely with larger doses.
Even more concerning is when Saxena and her team analyzed 31 supplements from 16 different brands they found that more than a quarter of the supplements also tested positive for serotonin, a strictly controlled substance, which is a mood stabilizer that can lead to serious side effects.
Researchers concluded that patients should consult with their doctors before taking melatonin as a dietary supplement.
Source: News Medical Life Sciences