By 2018, adults in the U.S. were taking more than twice the amount of melatonin they took a decade earlier, the researchers found. Health experts are concerned that the COVID-19 pandemic may have increased this trend as more people rely on sleep aids.
Overall melatonin use in the U.S. is still “relatively low,” but the study does “document a significant many-fold increase in melatonin use in the past few years,” Rebecca Robbins, PhD, an instructor of sleep medicine at Harvard Medical School who wasn’t involved with the study, told CNN.
The study, which looked at melatonin use between 1999 and 2018, found that a small but growing number of adults are taking doses that exceed the recommended 5 milligrams per day as a short-term treatment.
Short-term melatonin use for jet lag or occasional sleep problems appears to be safe, according to health information from the National Center for Complementary and Integrative Health. But the long-term safety is unknown.
Melatonin use has been linked to headaches, dizziness, nausea, stomach cramps, drowsiness, confusion, crankiness, mild anxiety, depression, tremors, and abnormally low blood pressure, CNN reported. It can also interact with common medications and trigger allergies.
Over-the-counter melatonin isn’t fully regulated by the FDA, the news outlet reported, so certain pills and formulations may contain higher levels than what is advertised on the label. No federal requirements compel companies to test the supplements to ensure they contain the advertised amount.
There also aren’t any federal requirements for companies to test products for harmful additives, CNN reported. Previous studies have found that 26% of melatonin supplements contained serotonin, which can lead to serious drug reactions when combined with antidepressants or migraine medications.
Melatonin is a hormone produced by the pineal gland in the brain. It is released into the bloodstream to regulate circadian rhythms and sleep-wake cycles. Instead of taking high amounts of melatonin, sleep specialists recommend improving “sleep hygiene” to help the body’s natural production of the hormone, Johns Hopkins reported.
That includes putting devices away an hour before falling asleep to reduce artificial light, sleeping in a cool environment, creating a consistent sleep schedule, and having a soothing bedtime routine such as a warm bath or meditation.
“Most people’s bodies produce enough melatonin for sleep on their own,” Luis Buenaver, PhD, a sleep expert at Johns Hopkins, said in a statement. “However, there are steps you can take to make the most of your natural melatonin production.”