WEDNESDAY, March 1, 2017 (HealthDay News) — If you take melatonin supplements to help you nod off, take note: Many brands are inaccurately labeled, containing much less — or much more — of the sleep hormone than indicated, a new study reports.
What’s more, a laboratory analysis found that eight of 31 melatonin supplements contained significant quantities of the drug serotonin, which is used to treat neurological disorders, the researchers said.
“There does exist a safety concern,” said study co-author Praveen Saxena of the University of Guelph in Ontario, Canada. He directs of the Gosling Research Institute for Plant Preservation at the university.
Scientists who analyzed the sleep-hormone supplements purchased in Canada said more than 70 percent were misleadingly labeled. That is, the contents didn’t fall within 10 percent of the breakdown claimed on the label.
Melatonin content varied from as little as 83 percent less than claimed on the label to as much as 478 percent more, the investigators found.
And even samples taken from different lots of the same brand of supplement were found to vary as much as 465 percent, the study authors said.
The findings are a cause for real concern, said Josiane Broussard, a fellow with the University of Colorado’s integrative physiology department.
“That there was so much variability between what was listed on the bottle and the actual content is pretty scary, so it’s really important to get this information out to the public,” she said.
Melatonin is a natural hormone that helps maintain your daily cycle of sleep and wakefulness, because levels rise at night and drop in the morning. Melatonin supplementation has long been touted as a non-medicinal sleep aid or as a way to recover from jet lag.
More than 3 million Americans take melatonin, according to the U.S. National Center for Health Statistics. But because it’s considered a dietary supplement, rather than a drug, it is not subject to U.S. Food and Drug Administration regulations.
Prior research has suggested that melatonin can degrade depending on storage and transportation conditions, so the variability in content “was not especially surprising to us,” said Saxena.