Millions of Americans rely on melatonin to help them sleep. It’s inexpensive, widely available and often viewed as a gentle alternative to prescription sleep aids.
However, research from the American Heart Association (AHA) indicates that long-term use of this supplement is associated with cardiovascular risks.
Data presented at the AHA Scientific Sessions in November 2025 identified a correlation between chronic melatonin use and a higher incidence of heart failure. Older adults who use the hormone daily need to reevaluate their sleep routine, the findings suggest.
Researchers analyzed health records for more than 130,000 adults with insomnia using the TriNetX Global Research Network. They focused specifically on individuals who had been taking melatonin for at least one year.
Compared to non-users, those taking melatonin long-term showed a 90% increased risk of developing heart failure.
The data also tracked severe outcomes. Long-term melatonin users were 3.5 times more likely to be hospitalized for heart failure and nearly twice as likely to die from any cause during the five-year follow-up period.
Dr. Ekenedilichukwu Nnadi, the lead author of the study, noted in a summary of the findings:
“Melatonin supplements may not be as harmless as commonly assumed. If our study is confirmed, this could affect how doctors counsel patients about sleep aids.”
So while many view melatonin as a safe option, the increase in serious health outcomes suggests otherwise.
Understanding the supplement
Melatonin is a hormone that helps to regulate the circadian rhythm. In many countries, such as the United Kingdom and parts of the European Union, it’s classified as a prescription medication.
In the U.S., melatonin is sold over the counter as a dietary supplement. This classification means it’s not subject to the same strict FDA regulations as pharmaceuticals. Dosage consistency can vary between products, and consumers may inadvertently take doses much higher than what the body produces naturally.
The AHA study indicates that chronic exposure to high levels of this hormone may interact with cardiovascular mechanisms.
Factors such as stress or the severity of insomnia itself could contribute to heart risks in the population studied. However, the researchers adjusted for many of these variables and maintained that the link remained significant.
Nnadi emphasized that while the study does not prove melatonin causes heart failure, the safety signal warrants caution. Individuals with existing heart risk factors should discuss these findings with a physician.
Alternatives to consider
For those concerned about these findings, sleep specialists often recommend using melatonin only for short-term issues, such as jet lag, rather than for chronic insomnia.
There are other methods to address sleep difficulties:
- Cognitive Behavioral Therapy for Insomnia (CBT-I): This approach treats the underlying behaviors and anxieties that prevent sleep.
- Magnesium glycinate: Some evidence suggests this mineral may aid relaxation.
- Light hygiene: Reducing exposure to blue light from screens 60 minutes before bed can support natural sleep cycles.
Sleeping pills aren’t a better alternative, as we reported in “7 Ways Sleep Medications Are Hazardous to Health (and What Experts Say to Do Instead).”
But you do have several natural ways to deal with sleep deprivation. Learn more in “7 Sleep Tricks That Actually Work.”
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