Long-Term Melatonin Use Linked to Higher Heart Failure Risk, Preliminary Findings

A large, multi-country analysis of about 130,000 adults found that long-term melatonin prescriptions (>1 year) were associated with an 89% higher risk of heart failure and roughly double the odds of death over five years versus those not prescribed melatonin. The study is preliminary, not peer‑reviewed, and relies on prescription records to infer melatonin use—OTC use in the control group could bias results. While melatonin is commonly used and generally safe short‑term, these findings underscore the need for prospective trials to clarify safety and guidance for long-term use.