A recent preliminary study has sparked discussions about the long-term safety of melatonin, a popular sleep aid, suggesting a potential link to an increased risk of heart failure. However, leading cardiologists are urging the public not to panic, emphasizing that the research does not prove the supplement itself is the cause.
What the Study on Melatonin and Heart Health Found
The research, presented at an American Heart Association meeting in November 2025, analyzed international electronic health records of adults diagnosed with insomnia. It focused on patients whose records indicated they had used a prescribed melatonin supplement for at least one year.
Over a five-year observation period, the findings revealed that 4.6% of chronic melatonin users developed heart failure. In comparison, heart failure was observed in 2.7% of insomnia patients who did not have recorded melatonin use. The study's authors from SUNY Downstate Health Sciences University described these results as a signal that warrants more in-depth investigation.
Why Experts Say Not to Panic Over the Melatonin Findings
Medical professionals have been quick to highlight the significant limitations of this observational study. A key point of caution is that this type of research cannot prove that melatonin use causes heart failure.
"We should not raise the alarm and tell patients to stop taking all their melatonin," stated Dr. Pratik Sandesara, an interventional cardiologist at Emory Healthcare who was not involved in the research. He and other experts suggest that the underlying insomnia, which is a known risk factor for heart disease, could be the real culprit, not the supplement used to treat it.
Further complicating the findings are issues with the data. Melatonin is an over-the-counter supplement in the United States, unlike in some other countries where it requires a prescription. Dr. Clyde Yancy, chief of cardiology at Northwestern University, pointed out that this means the study likely missed Americans who purchased melatonin without a prescription, making the data incomplete. The study also did not account for the dosages taken by participants.
Key Takeaways and the Path to Better Sleep
So, what should individuals currently taking melatonin do? The consensus among experts is to have a conversation with your doctor. Melatonin, a hormone our bodies produce naturally to regulate sleep cycles, is generally considered safe for short-term use, such as managing jet lag.
However, Dr. Yancy noted that while the study doesn't confirm a danger, "there's also no evidence that people should use melatonin indefinitely." The more reliable path to improving sleep, according to doctors, is to focus on better sleep hygiene.
This includes practices like ensuring your bedroom is completely dark. "When we expose ourselves to blue light in particular at night, we are diminishing our melatonin levels. That's science," explained Dr. Yancy. He stressed that addressing sleep problems is critical, as they aren't just about feeling tired—"they're putting yourself at risk" for broader health issues, including heart disease.
