Melatonin use significantly increases across US
The reported prevalence of melatonin use significantly increased among adults in the United States during a recent 20-year period, survey data show.
During this timeframe, researchers also found an increase in self-reported melatonin use that exceeded the typically recommended daily dosage of 5 mg. Although, overall, the prevalence of higher-dose melatonin use remained “very low,” researchers wrote.
Previous research has suggested that one in 17 children takes melatonin at least once per week.
Melatonin, “one of the key hormones governing circadian rhythm, is indicated for treatment of circadian rhythm sleep disorders and, despite insufficient evidence, is widely used as an over-the-counter sleep aid,” Jingen Li, MD, PhD, of Dongzhimen Hospital and the Beijing University of Chinese Medicine, and colleagues wrote in the new study.
The supplement’s antioxidant and anti-inflammatory properties have spurred studies into its possible therapeutic value for several diseases, they wrote.
“Although melatonin is generally regarded as safe, adverse effects have been reported, and data on long-term use and high-dose use are scarce,” Li and colleagues continued. “The heterogeneity in over-the-counter formulations further supports the need for a broader understanding of consumption of exogenous melatonin in the population.”
The researchers analyzed National Health and Nutrition Examination Survey (NHANES) data regarding dietary supplement use during the past 30 days. They also looked at daily dose consumed from 1999 to 2000 through 2017 to 2018 cycles and noted that NHANES did not track melatonin use that exceeded 5 mg daily until its 2005 to 2006 survey. The analysis included information from 55,021 adults (mean age, 47.5 years; 52% women), of whom 93.9% had verified supplement use.
Li and colleagues reported in JAMA that the overall reported weighted prevalence of melatonin use increased from 0.4% (95% CI, 0.2-1) in 1999 to 2000 to 2.1% (95% CI, 1.5-2.9) in 2017 to 2018, and that the first uptick in melatonin consumption was reported in the 2009 to 2010 survey. Although trends closely and significantly aligned among all sex and age cohorts, some subgroups had a small number of reported melatonin users. The researchers recommended interpreting the subgroup analyses with caution. The reported prevalence of melatonin use greater than 5 mg daily increased from 0.08% (95% CI, 0.02-0.38) in the 2005 to 2006 survey to 0.28% (95% CI, 0.13-0.6) in the 2017 to 2018 survey.
“These estimates may raise safety concerns, especially given that the actual content of melatonin in marketed supplements may be up to 478% higher than the labeled content and that evidence supporting melatonin use for sleep disturbances is weak,” Li and colleagues wrote. “The growing use of exogenous melatonin in the general population and its expanding therapeutic potential provide impetus for the acquisition of robust evidence of long-term safety of melatonin supplementation.”