02/20/2026
Melatonin is widely used as a sleep aid, but new research suggests long term use may be linked with unexpected heart risks in some people. Scientists analyzed health records from a large group of adults diagnosed with chronic insomnia and compared those who used melatonin regularly with those who did not. Over several years of follow up, people taking melatonin showed higher rates of heart failure diagnoses and hospitalizations than non users.
The study does not show that melatonin directly damages the heart. Instead, it highlights an association that remained even after accounting for age and other health conditions. One possibility is that people with severe or long lasting sleep problems already carry higher cardiovascular risk due to chronic stress, disrupted hormones, and inflammation. Melatonin use may simply mark a group that is already vulnerable rather than being the cause itself.
Melatonin is a hormone naturally produced by the body to regulate sleep and circadian rhythm. Supplementing it can help some people fall asleep, especially in short term or specific situations. However, taking it nightly for long periods may alter natural hormone signaling, blood pressure regulation, or heart rhythm in ways that are not fully understood.
Because this research was observational, it cannot prove cause and effect. It does suggest that long term melatonin use should not be assumed harmless, especially for people with insomnia and existing cardiovascular risk. More controlled human studies are needed to clarify who benefits and who may be at risk.
SOURCE : American Heart Association
Long-term use of melatonin supplements, a preliminary study to be presented at the American Heart Association’s Scientific Sessions 2025.
