New Research Highlights Heart Risks of Long-Term Melatonin Use
Using melatonin supplements for extended periods to treat sleep issues may pose serious cardiovascular dangers. Recent research indicates that people who use melatonin chronically have nearly double the risk of death and are 3.5 times more likely to be hospitalized due to heart failure.
Study Findings Presented at AHA 2025
A preliminary study shared at the American Heart Association's (AHA) Scientific Sessions 2025 revealed concerning outcomes for adults with chronic insomnia who took melatonin for a year or more. They showed a higher likelihood of developing heart failure, increased hospital admissions for heart failure, and greater all-cause mortality compared to those not taking melatonin.
The AHA’s annual meeting, held November 7-10 in New Orleans, is a major event for cardiovascular science and clinical updates where this research will be further discussed.
What Is Melatonin?
Melatonin is a hormone produced by the pineal gland that controls the body's sleep-wake rhythm. Its levels increase naturally in darkness and decrease during daylight. Synthetic melatonin supplements, chemically identical to the natural hormone, are commonly used to address insomnia and jet lag.
Availability and Regulation
- Melatonin is available over the counter in many countries, including the U.S.
- In the U.S., it is not regulated as a medication, resulting in variations in supplement purity and dosage.
"Though melatonin is widely regarded as harmless, experts now urge caution with extended use."
Given these findings, individuals and healthcare providers should carefully consider the potential heart-related risks when using melatonin for long-term sleep management.
Author’s summary: New research associates long-term melatonin use with increased risks of heart failure and mortality, suggesting careful evaluation before prolonged supplementation.