Long-term Use of Melatonin Supplements May Pose Health Risks
A review analyzing five years of health records for over 130,000 adults with insomnia who used melatonin supplements for at least one year found increased risks related to heart failure.
Key Findings from the Study
- Long-term melatonin use was linked to a greater likelihood of being diagnosed with heart failure.
- Users had higher rates of hospitalization due to heart failure.
- There was an increased risk of death from any cause among chronic insomnia patients taking melatonin.
“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,” a preliminary study presented at the American Heart Association’s Scientific Sessions 2025 noted.
Context of the Research Presentation
The study was presented at the American Heart Association’s Scientific Sessions 2025, held in New Orleans from November 7-10, which serves as a major platform for sharing advances in cardiovascular science and clinical practice.
About Melatonin
Melatonin is a hormone naturally produced by the pineal gland that regulates the sleep-wake cycle. Its levels rise in the dark and fall during daylight hours.
Synthetic melatonin supplements, chemically identical to the natural hormone, are commonly used to treat insomnia and jet lag. These supplements are readily available over the counter in many countries, including the United States.
Supplement Quality and Regulation
In the U.S., over-the-counter melatonin supplements are not subject to government approval for quality or consistency, leading to variations in strength and purity among different brands.
“Over-the-counter supplements do not require government approval to ensure quality and consistency, so each brand of supplement can vary in strength, purity, etc.”
Summary: Long-term melatonin supplementation for insomnia may increase risks of heart failure and mortality, highlighting the need for caution and better regulation of supplement quality.
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