The Study
Abstract 4371606: Effect of Long-term Melatonin Supplementation on Incidence of Heart Failure in Patients with Insomnia
This study looks at medical records to see if people who took melatonin for a long time were more likely to get heart problems compared to those who didn't. It shows that the two things happened together, but because it wasn't a controlled experiment, we can't say the melatonin definitely caused the heart problems.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Researchers analyzed electronic health records to see if adults with insomnia who take melatonin long-term face higher risks of heart problems or death compared to those who do not.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 559 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The increased risks are statistically significant and clinically notable, suggesting chronic melatonin therapy may carry cardiovascular and mortality risks that patients and doctors should consider.
- 2Over 5 years, melatonin users had a 4.6% heart failure rate versus 2.7% in non-users, a 19.0% hospitalization rate versus 6.6%, and a 7.8% death rate versus 4.3%.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Circulation
Year
2025
Authors
E. Nnadi, Maureen Masara, R. Offor, Selin Unal, Rebhi Rebah, Muhammed Atere, Bisrat Nigussie, Suzette B. Graham-Hill
Related Content
Claims (5)
Taking melatonin for sleep over a long period might slightly increase your chance of developing heart failure compared to not taking it. This small but noticeable increase in risk means doctors should keep an eye on heart health when prescribing it for insomnia.
Taking melatonin long-term to help with sleep might actually raise the risk of being hospitalized for heart failure. Research suggests people who use it over a long period face about three times the risk of serious heart problems compared to those who don't take it.
Adults with insomnia who take melatonin long-term appear to have a higher risk of dying from any cause over five years compared to those who don't take it. This suggests that chronic melatonin use might carry hidden health risks for people with sleep problems.
Using melatonin long-term to treat insomnia might actually increase the risk of serious heart problems and death, according to recent real-world patient data.
When researchers study the safety of melatonin, mixing people who get it from a doctor with those who buy it over the counter can mess up the data. This mistake makes it look like the prescription version is more dangerous than it really is.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.