What You Need To Know About Melatonin & Heart Failure Risk
Melatonin is a go-to supplement for many, especially for those struggling with insomnia. This isn’t surprising as it’s often marketed as a safe and natural sleep aid. But now that’s being called into question.
New research being presented at the American Heart Association’s 2025 Scientific Sessions has linked long-term use of this hormonal sleep aid in people with insomnia with heart failure.
About the study
To look at this correlation, researchers reviewed 5 years of health records for more than 130,000 adults with diagnosed insomnia who took melatonin for at least a year and looked at their cardiovascular disease risk. They then compared those outcomes to those who did not take melatonin.
Melatonin use, insomnia & heart concerns
Overall, results showed that:
- About 4.6% of people who took melatonin long-term developed heart failure, compared to 2.7% of those who didn’t. That’s a nearly 90% higher risk.
- Long-term melatonin users were more than three times as likely to be hospitalized for heart failure as those who didn’t take melatonin (19% vs. 6.6%).
- Over the five-year period, nearly twice as many melatonin users died from any cause compared to those who didn’t supplement (7.8% vs. 4.3%).
“Melatonin supplements are widely thought of as a safe and ‘natural’ option to support better sleep, so it was striking to see such consistent and significant increases in serious health outcomes, even after balancing for many other risk factors,” said Ekenedilichukwu Nnadi, M.D., lead author of the study, in a statement.
The researchers stress that these results show an association, not proof of causation. Still, the consistency of the findings gives us reason to pause.
What does this mean for melatonin use?
“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,” said Ekenedilichukwu Nnadi, M.D., lead author of the study in a statement.
But there’s also a lot of nuance in these findings. Here’s why.
- Chronic insomnia is independently linked to a higher risk of heart problems, like heart failure.
- People who rely on melatonin for more than a year may be experiencing more severe disruptions from the condition, and melatonin use could be an indicator of overall sleep health rather than the cause of heart problems itself.
- This study identified “melatonin users” based on prescription records (because in many countries it’s considered a prescription medication), so many U.S. over-the-counter users may have been incorrectly grouped as non-users. That mix-up makes it harder to know exactly how big the difference really is.
Experts have long warned about the unknown safety effects of melatonin, and this study now gives even more reason to proceed with caution. So while there is data and while some experts agree that short-term (appropriately dosed) melatonin use may support short-term sleep support (say for occasional jet lag), it’s not a tool for nightly long-term use.
What else can you take and do for sleep?
Whether you have insomnia or struggles getting enough quality sleep, there are so many other options out there besides melatonin. Improving sleep hygiene (like avoiding late-night alcohol, making sure your room is dark and cool, and reducing screen time) are great starting points. If you’re looking for an alternative sleep-supping supplement to take, then opt for one that features magnesium.
Magnesium is an essential mineral that many of us (about 43% to be exact), don’t get enough of through diet alone.
When magnesium levels dip, the effects can show up in subtle but wide-ranging ways—think heightened stress, muscle tightness, restless sleep, and even shifts in mood. Taking magnesium before bed can help ease both the body and mind into relaxation mode.
It does this in part by activating receptors for GABA, a neurotransmitter that quiets an overactive nervous system1 and promotes calm, helping you not only drift off more easily but also stay asleep through the night.*
There are a lot of sleep supplements out there, so we rounded up our top picks here (with the best overall being a magnesium-based option).
The takeaway
While this study is preliminary, it suggests that long-term nightly use of melatonin may carry more risks than previously thought. Short-term use, good sleep habits, and supportive nutrients like magnesium remain safer ways to improve sleep naturally.