Think Melatonin Is Safe? New Research Reveals a Hidden Heart Risk
Recent findings suggest that long-term use of melatonin, a popular sleep aid, may carry significant heart-related risks. Researchers discovered that individuals who used melatonin chronically were nearly twice as likely to die and 3.5 times more likely to be hospitalized for heart failure compared to non-users.
New Concerns About Prolonged Melatonin Use
Although melatonin has long been seen as a harmless remedy for sleep issues, new data suggest a need for caution. A study presented at the American Heart Association's Scientific Sessions 2025 revealed that adults with persistent insomnia taking melatonin for a year or longer had higher rates of heart failure, hospitalization, and all-cause mortality.
“Adults with chronic insomnia who used melatonin for a year or longer were more likely to develop heart failure, be hospitalized for heart failure, and die from any cause,” the researchers reported.
Background on Melatonin
Melatonin is a hormone naturally produced by the pineal gland, helping regulate the body’s sleep-wake rhythm. Its production rises after sunset and drops during daylight. Synthetic melatonin, which mirrors the natural hormone, is widely marketed to combat insomnia and jet lag.
Regulation and Availability
- Melatonin supplements are available over the counter in many countries, including the United States.
- In the U.S., melatonin is not regulated by federal health authorities, leading to variations in product purity and dosage.
The study’s findings will be discussed during the AHA’s annual meeting, held November 7–10, 2025, in New Orleans — a leading international forum for cardiovascular research and advances.
Author Summary
New evidence links long-term melatonin use to a higher risk of heart failure, prompting experts to advise careful evaluation before prolonged supplementation.