Melatonin Linked to Heart Failure Risk

A new preliminary study, presented at the American Heart Association's Scientific Sessions 2025, has linked the long-term use of Melatonin supplements to a significantly higher risk of heart failure, hospitalization, and death. Researchers, led by Ekenedilichukwu Nnadi, reviewed five years of health records for over 130,000 adults with chronic insomnia. They found that patients using Melatonin for a year or more had about a 90% higher chance of heart failure, were 3.5 times more likely to be hospitalized for heart failure, and nearly twice as likely to die from any cause compared to non-users. Marie-Pierre St-Onge, a professor at Columbia University Irving Medical Center, expressed surprise at the chronic prescription of Melatonin for insomnia, noting its unregulated status as an over-the-counter supplement in the United States. The study, which utilized data from the TriNetX Global Research Network, acknowledges limitations, including a lack of information on insomnia severity and other psychiatric disorders, and emphasizes that it cannot prove a direct cause-and-effect relationship, calling for more research into Melatonin's cardiac safety. The Council for Responsible Nutrition, a trade association, highlighted that previous studies indicate low-dose, short-term supplementation is safe.