Long-term Melatonin Use Linked to Negative Health Outcomes
A review of five years of health data involving over 130,000 adults with insomnia who used melatonin supplements for at least one year revealed an increased risk of heart failure diagnosis, hospitalization due to heart failure, and all-cause mortality.
Study Overview
The preliminary research, presented at the American Heart Association’s Scientific Sessions 2025 in New Orleans, highlights potential risks of chronic melatonin supplementation in individuals with long-term insomnia.
About Melatonin
Melatonin is a hormone naturally secreted by the pineal gland that regulates the sleep-wake cycle. Levels rise during darkness and fall with daylight. Synthetic melatonin supplements, chemically identical to the natural hormone, are frequently used to treat insomnia and jet lag.
Availability and Regulation
These supplements are widely available over the counter in many countries, including the U.S.
- In the United States, over-the-counter melatonin products do not require government approval for quality or consistency.
- This lack of regulation means supplement strength and purity can vary significantly between brands.
"Long-term use of melatonin supplements, often used to promote sleep and address insomnia, was associated with a higher risk of heart failure diagnosis, heart failure hospitalization and death from any cause in chronic insomnia."
The American Heart Association’s Scientific Sessions 2025 is a leading global event that shares the latest discoveries and clinical updates in cardiovascular science.
Summary
Melatonin supplements, while helpful for sleep issues, may pose health risks with prolonged use, especially related to heart health in chronic insomnia patients.
Author's summary: Long-term melatonin use for insomnia may increase heart failure risks and mortality, underscoring the need for caution and further research on supplement safety.