Full Breakdown
Long-Term Melatonin Use Linked to Increased Heart Failure Risk
11/5/2025, 2:39:51 AM
Study Overview and Findings
Recent research presented at the American Heart Association’s Scientific Sessions 2025 indicates that long-term use of melatonin supplements may be associated with a significantly increased risk of heart failure. The study analyzed five years of health records from over 130,000 adults diagnosed with chronic insomnia, revealing that those who used melatonin for at least 12 months had a 90% higher chance of developing heart failure compared to non-users. Specifically, 4.6% of melatonin users developed heart failure, compared to 2.7% of those who did not use the supplement. Additionally, melatonin users were nearly 3.5 times more likely to be hospitalized for heart failure and almost twice as likely to die from any cause during the study period.
Background and Context
Melatonin is a hormone produced by the pineal gland that regulates the sleep-wake cycle. It is commonly marketed as a safe, natural sleep aid, leading to its widespread use, particularly in the United States. However, the long-term cardiovascular safety of melatonin has not been thoroughly investigated until now. The study's lead author, Dr. Ekenedilichukwu Nnadi, emphasized the unexpected nature of the findings, stating, “Melatonin supplements may not be as harmless as commonly assumed.”
Key Figures and Groups
The study was conducted by researchers utilizing the TriNetX Global Research Network, which provided a large database of electronic health records. Dr. Nnadi, a chief resident in internal medicine at SUNY Downstate/Kings County Primary Care, led the research, highlighting the need for further investigation into the cardiovascular implications of melatonin use.
Criticism and Opposition
While the study presents alarming associations, experts caution against jumping to conclusions. Dr. Phyllis Zee, Director of Circadian and Sleep Medicine at the Feinberg School of Medicine, noted that the study lacked a well-controlled design and called for more research to clarify the findings. Other experts, such as Dr. Joyce Oen-Hsiao from Yale School of Medicine, pointed out that existing studies have not shown a direct causal link between melatonin and heart failure, suggesting that underlying health issues related to insomnia may contribute to the observed risks.
Official Statements and Responses
The American Heart Association acknowledged that the study does not establish a cause-and-effect relationship but raises important safety concerns regarding melatonin use. Dr. Nnadi reiterated the need for caution, stating, “This means more research is needed to test melatonin’s safety for the heart.”
Conflicting Reports and Gaps
Despite the study's findings, there is a lack of consensus in the medical community regarding the safety of melatonin. Some studies have suggested potential health benefits of melatonin for individuals with heart failure, creating a complex narrative around its use. The current research relies on electronic health records, which may not capture over-the-counter melatonin use, potentially skewing results.
What's Next
The findings from this preliminary study will be further explored in future research, with calls for more controlled studies to better understand the relationship between melatonin use and heart health. As the conversation around melatonin continues, healthcare professionals are encouraged to evaluate patients’ sleep concerns within a broader clinical context, emphasizing non-pharmacologic strategies for managing insomnia.
