A review of five years of health records involving over 130,000 adults with insomnia who used melatonin supplements for at least one year found increased risks related to heart failure and mortality.
The study, to be presented at the American Heart Association’s Scientific Sessions 2025 in New Orleans, revealed that chronic melatonin use was associated with:
Melatonin is a hormone naturally produced by the pineal gland, regulating the sleep-wake cycle. Its levels rise at night and fall during daylight. Synthetic melatonin supplements, chemically identical to the natural hormone, are widely used to treat insomnia and jet lag.
In many countries, including the U.S., melatonin supplements are sold over the counter without the need for government approval, resulting in variability in strength and purity among different 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 is a leading event that showcases the latest cardiovascular research and clinical practice updates.
Chronic melatonin use for sleep support may increase heart failure risks and mortality, highlighting the need for cautious use and further research on long-term effects.