Melatonin and Heart Health: A Growing Concern?
Millions rely on melatonin to navigate sleepless nights, but a recent study is prompting a closer look at the long-term effects of this popular supplement. Emerging research suggests a potential link between prolonged melatonin use and an increased risk of heart failure, raising questions about its widespread availability and perceived safety.
The Study: What Did Researchers Discover?
A preliminary study presented at the American Heart Association (AHA) conference in November 2025 analyzed the medical records of 130,828 adults with chronic insomnia. Researchers discovered that individuals taking melatonin for a year or more exhibited a higher probability of developing heart failure. Specifically, those using melatonin long-term showed a 89% increase in the risk of heart failure over five years, along with increased rates of cardiac hospitalization and overall mortality.
Heart Failure (Association)
2.7%
Hospitalization for Heart Failure (Association)
6.6%
All-Cause Mortality (Association)
4.3%
Heart Failure (Association)
4.6% (+89%)
Hospitalization for Heart Failure (Association)
19% (x3.5)
All-Cause Mortality (Association)
7.8% (x1.8)
It’s crucial to note that this study demonstrates an association, not a direct cause-and-effect relationship. Researchers emphasize that further investigation is needed.
Who is Most at Risk?
In France, approximately 1.4 million boxes of melatonin-based supplements are sold annually. Seniors are particularly frequent users, as natural melatonin production tends to decline with age. Many individuals take melatonin nightly for extended periods without medical supervision, a pattern linked to the observed risk in the study.
Melatonin’s Effectiveness: A Nuanced Picture
The French National Institute of Health and Medical Research (Inserm) published an analysis in September 2024 indicating that melatonin supplements can modestly reduce sleep onset time, particularly in individuals over 55. However, studies show limited effects on nighttime awakenings or overall sleep quality. This suggests many are taking a product with modest benefits for extended durations, assuming it’s entirely harmless.
What Should You Do Now?
If you regularly use melatonin, especially if you are over 50 or have pre-existing cardiovascular conditions, discussing its use with your doctor is essential. Cognitive Behavioral Therapy for Insomnia (CBT-I) remains the gold standard treatment for chronic insomnia.
Key Takeaways
- An American study of 130,000 insomnia sufferers associates long-term melatonin use (≥1 year) with an increased risk of heart failure (+89%), without establishing a causal link.
- Hospitalizations for heart failure were 3.5 times more frequent among long-term users.
- The effectiveness of over-the-counter melatonin supplements remains modest, according to Inserm, especially for nighttime awakenings.
- The French National Agency for Food, Environmental and Occupational Health Safety (ANSES) recommended limiting use to occasional instances and consulting a doctor in 2018.
- If you take it regularly, talk to your doctor. CBT-I remains the preferred solution for chronic insomnia.
