Long-Term Melatonin Use Tied to Higher Heart Failure Risk in Large Sleep-Health Study
A large international analysis of more than 130,000 adults with chronic insomnia found that long-term melatonin use (≥12 months) was associated with an 89–90% higher five-year risk of heart failure (4.6% vs 2.7%), about a 3.5-fold increase in heart-failure hospitalizations (19.0% vs 6.6%), and nearly double the risk of all-cause death (7.8% vs 4.3%). The results show association, not causation, and are based on medical records; they are preliminary and not yet peer-reviewed, prompting calls for prospective trials to clarify safety.
