Long-term use of melatonin supplements may pose health risks
Research Overview
A five-year review of medical records for more than 130,000 adults with insomnia revealed that those who had taken melatonin supplements for at least one year faced increased rates of heart failure diagnosis, hospitalization for heart failure, and mortality from any cause.
Study Details
The findings, based on preliminary research to be presented at the American Heart Association’s Scientific Sessions 2025 in New Orleans, highlight potential long-term cardiovascular risks associated with frequent melatonin use.
Melatonin is a hormone naturally produced by the pineal gland that helps regulate the body’s sleep–wake cycle.
Levels of melatonin rise in darkness and decrease with light exposure. Synthetic forms, made to mimic the natural hormone, are often used to treat insomnia and jet lag. These supplements are easily accessible without a prescription in many countries, including the United States.
Quality Concerns
In the U.S., over-the-counter supplements are not subject to regulatory approval or strict quality control, which means their potency and purity may vary widely among brands.
Author’s Summary
Long-term melatonin use may offer sleep benefits but poses potential heart health risks that require further scientific evaluation.