This Common Supplement May Increase Your Risk of Heart Failure, According to Cardiologists

Sleep may not come easily these days for many reasons, such as workplace burnout, wanting to raise happy kids and your never-ending to-do list. You’re not alone, either, with 12 percent of Americans experiencing chronic insomnia.

Considering sleep is crucial for many reasons—including its effects on your mood, energy levels, immune system and even your eyes—sacrificing it is simply not an option.

There’s a supplement that’s been a game-changer for many of us with sleep concerns. It’s called melatonin, and it’s a hormone your body produces to promote the sleep-wake cycle. But unfortunately, according to a large 2025 review by the American Heart Association, taking it long-term may lead to heart failure. Further, “long-term” is defined by one year in this study, which arguably isn’t all that long. Pretty terrifying, right?

Not addressing your sleep issues or going cold turkey on melatonin isn’t a surefire solution, however, especially when it comes to heart health. After all, a consistent sleep routine can reduce your risk of heart disease. Some cardiologists would even say that sleep is the most overlooked heart-healthy habit, and for many, melatonin helps.

The study’s data and potential explanations add extra complexity, so Parade turned to cardiologists for a better understanding. Ahead, those cardiologists share how long-term melatonin use may increase heart failure risk, how worried to be and their recommendations.

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How Long-Term Melatonin Use May Increase Heart Failure Risk

To be clear, the study is a case of correlation, not causation. In other words, we don’t know for sure if taking melatonin daily for a year directly raises heart failure risk.

Further, cardiologists note that the mechanism or connection between the two—if there is one—isn’t fully understood, but they have theories.

“It is possible that the higher dosage of exogenous melatonin may overstimulate specific chemical receptors in the heart, which can lead to abnormal cardiac remodeling, increasing the risk of congestive heart failure,” says Dr. Bradley Serwer, MD, an interventional cardiologist and chief medical officer at VitalSolution. “We may speculate that there are alternations in the circadian rhythms or issues with labile blood pressures as a result of the supplemental medication.”

There are three other possible explanations. One is a confounding variable. “People with severe, chronic insomnia (and often stress, depression, pain or sleep apnea) are more likely to take melatonin and already carry higher cardiometabolic risk,” says Dr. Sam Setareh, MD, a staff cardiologist at Cedars-Sinai Medical Center, senior clinical researcher at the National Heart Institute and director of clinical cardiology at Beverly Hills Cardiovascular.

The second possibility he mentions is that taking melatonin at suboptimal times or in higher doses could worsen circadian alignment, autonomic tone and blood pressure patterns. Taking higher doses than necessary could be more common than we’d think, too, since over-the-counter melatonin can vary widely in dose and purity.

Last but not least, “Interaction with unrecognized sleep apnea is common, raises heart failure risk, fragments sleep and may drive supplement use,” Dr. Setareh says.

That’s a lot of big words to essentially say this: Heart health and sleep health are closely intertwined in many ways, and melatonin use may or may not factor into this.

If You Take Melatonin, How Worried Should You Be?

Yes, the finding sounds bad—but remember that it’s a case of correlation, not causation. What level of concern feels accurate? “Concerned enough to re-evaluate routine [and] nightly use, but not panicked,” is Dr. Setareh’s response.

He adds that the size and consistency of the study justify caution, especially in people who have other risk factors for heart failure, such as hypertension, diabetes, obesity, kidney disease or other conditions.

There’s also the fact that medications and supplements have real health effects, even if this isn’t one of them. “This study raises several clinical concerns,” Dr. Serwer says. “We must always consider that every medication we consume has a risk and a benefit.”

Cardiologists’ Recommendations for Melatonin Use

Given those insights, what do cardiologists suggest people do?

Dr. Serwer encourages non-pharmacologic options for insomnia, such as meditation, exercise, avoiding caffeine, avoiding bright lights before bed and addressing any mental health concerns. He adds that short-term usage of melatonin hasn’t been shown to have adverse consequences yet, so taking it for a shorter period or less often could be a safer option.

Dr. Setareh’s suggestion is similar: “For most users, I advise shifting from chronic nightly dosing to short-term, situational use (jet lag, shift transitions) and, if still needed, using the lowest effective dose—often one milligram taken two to three hours before bed—with periodic attempts to taper off.”

When it comes to melatonin use, popping one of those gummies nightly might be harmful long-term—and you don’t have to give it up completely. The data found is discouraging, but it’s only a start. Being mindful of your use is vital.

“Melatonin isn’t a ‘vitamin for sleep,’” Dr. Setareh says. “Until we have peer-reviewed, prospective data with adjudicated outcomes, treat it as a short-term aid, keep doses low and focus on durable, evidence-based strategies that improve sleep—and heart health—without adding risk.”

Up Next:

Next up: ‘I Have Chronic Insomnia—Here’s Everything I Do When I Can’t Sleep’

Sources

This story was originally reported by Parade on Nov 13, 2025, where it first appeared in the Health & Wellness section. Add Parade as a Preferred Source by clicking here.

This Common Supplement May Increase Your Risk of Heart Failure, According to Cardiologists

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