New research is raising concerns about long-term melatonin use. According to the American Heart Association, a study found that people who took melatonin for more than a year had a higher risk of developing heart failure within five years compared to nonusers.

They were also more likely to be hospitalized for heart failure or to die of any cause than those who did not take the supplement.

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The findings, which have not yet been peer reviewed, have sparked debate among both sleep medicine specialists and cardiologists.

Renowned cardiologist Dr. Chauncey Crandall, director of preventive medicine at the Palm Beach Cardiovascular Clinic in Florida, shared with Newsmax’s “Newsline” that the research highlights an important caution for people who rely on melatonin to sleep.

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“I think the bottom line is that melatonin is good short term,” Crandall said. “But this study has showed that people that take it continuously over a year have increased incidence of heart failure, death, hospitalization. So, it is telling us something. There is something wrong with taking this hormone.”

Melatonin is naturally produced by the pineal gland in the brain — a structure Crandall describes as “only about the size of a piece of rice” but with “profound effects” on the body’s sleep cycle.

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He notes that sleep problems have become much more common over the decades. “Fifty years ago, maybe 2% of the population had a sleep disorder. Today, it is over 25%. So sleep is a problem,” explained Crandall, editor of the popular newsletter Dr. Crandall's Heart Health Report.

Crandall believes melatonin can be effective for temporary use, such as during jet lag or short-term insomnia, but cautions against daily, long-term use. “Our brains are hyperstimulated today with the internet and the iPhone and everything that we use on the computer,” he explains. “We need to find a better way.”

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When asked whether people can overdose on melatonin, Crandall says it’s possible to disrupt the body’s natural rhythm. “Melatonin gives what they call a feedback loop. Your brain secretes melatonin throughout the day — higher levels when it becomes dark — and that’s what puts you to sleep. But if you’re taking melatonin as a supplement, it suppresses your brain,” he said. “Over time you interrupt that sleep-wake cycle, or what we call the circadian rhythm. So, it is not a good thing to take long term.”

Crandall suggests safer alternatives for improving sleep naturally. “There are other options, such as chamomile tea, cherry juice, and magnesium,” he said. “Get off your computer and iPhone at night and get into bed early, and you’ll have a good night’s sleep.”