The overall use among the US adult population is still “relatively low,” but the study does “document a significant many-fold increase in melatonin use in the past few years,” said sleep specialist Rebecca Robbins, an instructor in the division of sleep medicine for Harvard Medical School. She was not involved in the study.
“In an associational study we found that older adults who reported frequent use — every night or most nights — of a sleep aid had a higher risk of incident dementia and early mortality,” Robbins said. Nor are there any requirements that companies test their products for harmful hidden additives in melatonin supplements sold in stores and online. Previous studies also found 26% of the melatonin supplements contained serotonin, “a hormone that can have harmful effects even at relatively low levels,” according to the National Center for Complementary and Integrative Health.
“So for someone who takes hours to fall asleep, probably the better thing for them to do is turn off their screens, or get 20 to 40 minutes of exercise each day, or don’t drink any caffeinated products at all,” Breuner said.