Study Finds Increased Heart Failure Risk with Long-Term Melatonin Use
A recent study reveals that adults with insomnia who use melatonin supplements over an extended period face a significantly higher risk of heart failure. This risk is about 90% greater compared to those who do not use melatonin.
Melatonin Use and Health Risks
Melatonin is widely used in the United States as an over-the-counter supplement to aid sleep. Nearly six million Americans take it to fall asleep quicker or extend sleep duration. However, new research presented at the American Heart Association (AHA) Scientific Sessions 2025 raises concerns about its safety with prolonged use.
Adults with insomnia who took melatonin for at least a year had a much higher chance of developing heart failure.
Study Details
- Researchers analyzed health records of over 130,000 adults with insomnia and no prior heart failure history.
- They compared those who used melatonin for more than a year to those who never used the supplement.
- Long-term melatonin users had about a 90% increased risk of developing heart failure within five years.
- In the UK, where melatonin is prescription-only, individuals with at least two prescriptions filled 90 days apart showed an 82% higher risk.
- Those using melatonin long-term were almost 3.5 times more likely to be hospitalized for heart failure than nonusers.
Health Outcomes and Mortality
The study also found that melatonin users with insomnia had an elevated chance of hospitalization and a higher overall risk of death within five years compared to non-users.
They also have a much greater chance of being hospitalized for heart failure or dying from any cause over the next five years.
Summary
This research suggests that prolonged melatonin use in adults with insomnia may come with significant cardiovascular risks, including a higher likelihood of heart failure, hospital admission, and mortality.
Author's conclusion: Long-term melatonin supplementation in insomnia patients appears linked to severe heart health risks, emphasizing the need for cautious use and further investigation.