Despite health risks, adult melatonin use increases significantly

A study published in the medical journal JAMA examines trends in the use of melatonin in over 55,000 adults, and found that the use of melatonin as an over-the-counter sleep aid “significantly increased across all demographic groups” from 1999 to 2018.

According to the report, the number of adults in 2018 using melatonin as a sleeping aid was more than twice as high as it had been just a decade earlier. The study concluded that, since 2006, the number of adults taking higher than the recommended 5mg per day dosage more than doubled.

Melatonin is a hormone made inside the pineal gland of the brain. The brain releases melatonin into the bloodstream, primarily at night, to help naturally regulate the body’s sleep-and-wake cycles. The study’s researchers note that melatonin supplements are indicated, and widely used, to help circadian rhythm disorders “despite insufficient evidence” of their long-term safety or efficacy.

That more adults may be taking over-the-counter aids to help them fall asleep isn’t surprising, especially in light of the significant increase in life stressors as a result of the pandemic. And the study does note that overall use of melatonin as a sleep aid in the United States remains “very low.”

While melatonin is “generally regarded as safe,” researchers do have concerns — not only that adults are steadily taking more than the recommended daily amount of melatonin, but also that “the actual content of melatonin in marketed supplements may be up to 478% higher than the labeled content,” which means adults don’t always know how much melatonin they’re taking — or the level of purity of the product.

Melatonin is not without health risks either. The report notes that “adverse effects have been reported, and data on long-term use and high-dose use are scarce.” Short-term side effects, meanwhile, can include daytime sleepiness, headaches, dizziness, nausea and irritability.

The study offers further support that more research is needed to understand not only the potential adverse health risks of long-term use of melatonin but also the integrity, purity and amount of melatonin sold to consumers over-the-counter.

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