Long-Term Melatonin Use Linked to Higher Heart Failure Risk in Insomnia Patients
Adults with chronic insomnia who took melatonin supplements for at least one year faced a 90% higher risk of developing heart failure over five years compared to non-users, according to a large retrospective analysis presented today at the American Heart Association’s Scientific Sessions 2025 (Abstract MP2306). The same group also showed 3.5 times higher odds of heart failure hospitalization and nearly double the risk of death from any cause. While the study cannot prove causation, it raises urgent safety questions about the world’s most popular over-the-counter sleep aid. Melatonin—marketed as a “natural” hormone mimic—is widely used for insomnia and jet lag. In the U.S., it is unregulated and available in varying doses; in the U.K., it requires a prescription. “Many assume melatonin is harmless, but our data suggest prolonged use may carry serious cardiovascular consequences,” said lead author Ekenedilichukwu Nnadi,…
