In a new preliminary study, the American Heart Association (AHA) claims long-term use of melatonin supplements was associated with a higher risk of heart failure.
According to the AHA, melatonin is a hormone naturally produced in the body by the pineal gland and helps regulate the body’s sleep-wake cycle. Melatonin supplements are often used as a sleep aid or for jet lag.
The analysis claims among adults with insomnia, long-term melatonin use led to a 90 percent higher chance of heart failure over a five-year span. There were also similar results—82 percent higher—for people who had at least two melatonin prescriptions* filled at least 90 days apart.
A secondary analysis found participants taking melatonin were nearly 3.5 times as likely to be hospitalized for heart failure and they were nearly twice as likely to die from any cause over a five-year period.
“Melatonin supplements are widely thought of as a safe and ‘natural’ option to support better sleep, so it was striking to see such consistent and significant increases in serious health outcomes, even after balancing for many other risk factors,” said Dr. Ekenedilichukwu Nnadi, lead author of the study and chief resident in internal medicine at SUNY Downstate/Kings County Primary Care in Brooklyn, New York.
The Council for Responsible Nutrition (CRN) and Natural Products Association (NPA) responded to the study.
CRN urged all stakeholders to interpret the findings with “caution and context.” As AHA stated, the data is early and non-peer reviewed so the data cannot establish cause and effect. Chronic insomnia, which was shared by all study participants, may be a contributing factor to heart health issues, raising more questions than answers.
As reported by The Washington Post, quality sleep is critical for cardiovascular health and individuals who sleep poorly tend to have higher heart rates and blood pressure and experience more cardiovascular events. CRN argues the study would be unlikely to apply to healthy adults who use melatonin supplements occasionally for sleep support.
According to CRN, melatonin supplements are not intended to treat chronic insomnia or other sleep disorders. CRN’s voluntary labeling guidelines from 2024 recommended upper dosage levels and advisory statements, such as “for occasional and/or intermittent use only” or “consult a health care professional if you are experiencing long-term sleep difficulties.”
“CRN supports ongoing scientific research to better understand long-term use patterns of all dietary supplements and welcomes rigorous, peer-reviewed investigations that contribute to evidence-based guidance,” CRN said. “However, no single study—especially a preliminary abstract—should serve as the basis for broad conclusions or alarmist headlines about dietary supplements. Consumers who use melatonin should consult their health care providers, particularly if they have cardiovascular concerns, before making any changes to their regimen.”
NPA noted AHA failed to recognize that dietary supplements sold in the United States are “not intended to treat, cure or prevent disease” as per language in the Dietary Supplement Health and Education Act of 1994 (DSHEA). The association also expressed disappointment in the erroneous statement that over-the-counter supplements “are not regulated.”
AHA also cited several study limitations including that the patient database did not include countries (including the U.S.) that don’t require a prescription for melatonin. These individuals who be considered the non-melatonin group.
This limitation raises questions about whether there is an actual cause-and-effect relationship and shows the study did not focus on occasional use of melatonin for sleeplessness or other conditions, or regulated supplements containing versions of melatonin, NPA said.
“We recommend that consumers with chronic sleeplessness and other chronic diseases always consult with their physicians to properly diagnose and treat their medical conditions,” said Daniel Fabricant, PhD, president and CEO of NPA. “The preliminary study examined whether melatonin use alters the risk of heart failure in chronic insomnia patients, which is not the supplement industry’s target population. Furthermore, the established literature demonstrates that short-term use of melatonin is safe. NPA agrees that consumers should not take melatonin supplements for chronic insomnia without a proper indication and in close consultation with a medical professional.”
*Only available as a prescription form in the United Kingdom.
For more information, visit www.heart.org, www.npanational.org or www.crnusa.org.
