A recent study presented at the American Heart Association’s scientific meetings has sparked concerns regarding the safety of melatonin, a widely used sleep aid in the UK. The research indicates that long-term users may face an increased risk of heart failure, raising important questions about its prolonged use.
Prescriptions for melatonin in the UK have surged, with 2.5 million prescriptions issued in England alone last year. This synthetic version of a naturally occurring hormone helps regulate the sleep-wake cycle and has long been considered safe for treating short-term sleep issues in adults. It is also prescribed under specialist supervision for children with learning disabilities or ADHD.
The study analyzed electronic health records of approximately 130,000 adults experiencing sleep difficulties over five years. Of these, half were melatonin users, while the other half did not take the drug. Findings revealed that individuals who used melatonin for at least a year had a heart failure hospitalization rate of 19 percent, compared to 6.6 percent among non-users. Additionally, long-term users exhibited higher rates of heart failure diagnoses and mortality from all causes.
While the researchers attempted to balance the comparison by matching users and non-users across 40 factors, including age and health conditions, the study only established an association rather than a direct causation. This distinction is crucial, as correlation does not prove that melatonin directly causes heart failure.
The report is currently limited to a 300-word summary, leaving out key details such as melatonin dosage, insomnia severity, and lifestyle factors. The methodology also raises concerns; it relied on electronic medical records instead of direct patient follow-up, which can create gaps in the data. The research utilized the TriNetX Global Research Network, an extensive international database, but discrepancies in healthcare practices could affect the results.
In the UK, melatonin is a prescription medication for specific conditions, while in the US, it is available over the counter. This difference complicates the study, as some individuals categorized as non-users may have purchased melatonin without it being recorded in medical records.
A significant question remains: why did one group receive melatonin while the other did not? It is possible that those prescribed the drug had more severe sleep issues, which could indicate underlying health problems, including heart conditions. If this is the case, melatonin may merely reflect an existing risk rather than being a causal factor.
Interestingly, previous studies involving heart failure patients suggested that melatonin might have protective effects on heart health by improving psychological well-being and heart function. Other research indicated its potential to alleviate symptoms in heart failure patients, positioning it as a safe complementary therapy.
Since this study has not undergone peer review and remains unpublished in a comprehensive format, its findings should be interpreted cautiously. While the results are concerning and warrant further investigation into the long-term effects of melatonin on heart health, they do not provide a definitive conclusion.
Healthcare professionals face a critical challenge: balancing the treatment benefits of melatonin against its potential risks. Poor sleep is linked to a range of health issues, including metabolic disorders and mental health challenges. Typically, doctors recommend lifestyle changes and therapy to improve sleep quality before considering medication.
The conversation surrounding melatonin is far from over. Until more substantial evidence emerges, it is premature to draw alarmist conclusions about its safety. As healthcare continues to evolve, ongoing research will be essential to determine the implications of prolonged melatonin use.


































