New Study Links Long-Term Melatonin Use to Increased Heart Failure Risk
A recent study presented at the American Heart Association (AHA) Scientific Sessions 2025 highlights possible dangers of prolonged melatonin use in adults with insomnia. The research reveals that adults using melatonin for at least one year face a significantly higher risk of developing heart failure.
Increased Risks Associated with Melatonin Use
- Long-term melatonin users have about a 90% greater chance of developing heart failure within five years compared to non-users.
- They are nearly 3.5 times more likely to be hospitalized due to heart failure.
- The risk of death from any cause during this period is also higher among melatonin users.
Study Details and Population
The study analyzed health records of over 130,000 adults diagnosed with insomnia but without any previous history of heart failure. Researchers compared individuals who took melatonin for more than a year with those who never used the supplement.
Findings from the UK
In the United Kingdom, where melatonin is available only by prescription, those who filled at least two prescriptions at least 90 days apart exhibited an 82% increased risk of heart failure, reinforcing the findings from the U.S. data.
"Adults with insomnia who took melatonin for at least a year had a much higher chance of developing heart failure compared to similar adults who did not use melatonin."
Melatonin remains one of the most popular over-the-counter sleep aids in the United States, used by nearly six million people to help fall asleep faster or extend sleep duration.
Summary
This study raises concerns over the safety of long-term melatonin use, especially for adults with insomnia, as its prolonged intake may significantly increase the risk of heart failure and related hospitalizations.
Author's Conclusion
Long-term melatonin use in adults with insomnia may substantially elevate heart failure risk and related complications, warranting caution in its extended use.