Written by Marybeth Gallagher, RN on February 16, 2022 — Fact checked by Alexandra Sanfins, Ph.D.

  • A good night’s sleep is essential for good physical health, cognitive performance, and emotional functioning. Numerous sleep studies have documented these facts over time.
  • More and more adults are taking over-the-counter (OTC) melatonin preparations to get a better night’s rest, but some of them may be taking this substance at dangerously high levels, a new study finds.
  • Experts worry that the coronavirus pandemic’s negative effect on sleep has further increased the reliance on melatonin and other sleeping aids.

In the recent study, researchers obtained data from ten cycles of the National Health and Nutrition Examination Survey (NHANES)Trusted Source, covering the years 1999 through 2018. This study included 55,021 adults, 52% of whom were women. The participants had a mean age of 47.5 years.

The results showed that in 2018, adults in the United States took more than twice the amount of this sleep aid than they did a decade earlier, which may pose a health risk in some individuals.

The study revealed that melatonin use increased from 0.4% in 1999–2000 to 2.1% in 2017–2018, with the increase beginning in 2009–2010.

The study was published in the Journal of the American Medical Association (JAMA)Trusted Source, and the lead author is Dr. Jingen Li, Ph.D., of Beijing University of Chinese Medicine.

The study

The study evaluated adults who took melatonin at the recommended dosage of 5 milligrams per day (mg/d), as well as those who exceeded that dosage. Before 2005–2006, the authors found that users did not report taking more than 5 mg/d, but the prevalence of taking more than 5 mg/d went from 0.08% in 2005–2006 to 0.28% in 2017–2018.

Although the overall use of melatonin in the U.S. is still relatively low, the study does “document a significant many-fold increase in melatonin use in the past few years,” according to sleep specialist Rebecca Robbins, Ph.D., who is an instructor in the division of sleep medicine at Harvard Medical School and was not involved in this study.