Long-term Melatonin Use Linked to Heart Failure Risk
New research has revealed surprising findings regarding long-term melatonin supplement use. The supplement, long considered a natural and safe solution for sleep disorders, is now linked to a significantly increased risk of heart failure.
Based on a review of electronic medical records of thousands of adults with chronic insomnia, those who took melatonin for a year or more had a 90% higher chance of developing heart failure within five years compared to participants with similar health factors who did not take melatonin.
The data also showed melatonin users were three times more likely to be hospitalised for heart failure and about twice as likely to die from any cause. The study’s results are scheduled to be presented at the American Heart Association’s Scientific Sessions 2025 on 7-10 November.
Dr. Ekenedilichukwu Nnadi, lead author of the study from SUNY Downstate/Kings County Primary Care in Brooklyn, stated the findings are striking given melatonin’s widespread reputation for safety. However, he emphasised the study does not prove a direct cause-and-effect relationship.
‘While the association we found raises safety concerns about this widely used supplement, our study cannot establish direct causation,’ Nnadi said. He added that further research is needed to assess melatonin’s safety for the heart.
Experts advise against panic, noting significant limitations in the study. The findings contradict earlier studies suggesting melatonin’s antioxidant properties may benefit heart function in heart failure patients.
Melatonin is a hormone naturally produced by the pineal gland in response to darkness. However, over-the-counter melatonin supplements are not subject to strict regulatory oversight like pharmaceuticals, meaning their actual active ingredient levels may be significantly higher than labelled.
Dr. Marie-Pierre St-Onge of Columbia University Irving Medical Center advised consulting a doctor before long-term melatonin use. ‘People should be aware that melatonin should not be taken chronically without proper medical indication,’ she stressed.
As alternatives, experts recommend improving sleep hygiene practices. If supplement use is still preferred, they advise seeking products with independent verification labels to ensure quality and ingredient safety. (CNN/I-2)