Long-term Melatonin Use and Health Risks
A review spanning over five years examined the health records of more than 130,000 adults with insomnia who used melatonin supplements for at least one year. The study found an increased likelihood of heart failure diagnosis, hospitalization due to heart failure, and death from any cause among chronic insomnia patients taking melatonin.
Study Presentation and Context
This preliminary research was presented at the American Heart Association’s Scientific Sessions 2025, held in New Orleans from November 7 to 10. This event showcases the latest scientific discoveries and clinical updates in cardiovascular health.
Melatonin Overview
Melatonin is a hormone naturally produced by the pineal gland that regulates the sleep-wake cycle. Its levels rise in darkness and fall with daylight. Synthetic melatonin, chemically identical to the natural hormone, is commonly used as a supplement to treat insomnia and jet lag.
Supplement Availability and Regulation
Melatonin supplements are widely available over the counter in many countries, including the United States. However, in the U.S., these supplements do not require government approval, leading to potential variations in strength and purity across 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 study highlights potential adverse effects of prolonged melatonin supplement use, especially in individuals with persistent sleep disorders.
Author’s summary: Extended melatonin supplement use for insomnia may raise heart failure risks and mortality, underscoring the need for cautious long-term use and further research.