Chronic melatonin use may raise the risk of heart failure, research suggests

Melatonin is a great sleep aid, but researchers are still scoffing at the side effects of the supplement, especially as long-term use becomes more common. And now, the first study to study today shows taking melatonin for more than a year can be linked to heart problems and early death.

The researchers studied the medical records of people with chronic insomnia, and found that those prescribed melatonin for at least a year were more likely to develop heart failure and more likely to die from any cause. The study has important limitations, the authors note, but the findings are encouraging scientists to look ahead to potential health risks.

“These findings challenge the idea of ​​melatonin as a benign therapeutic agent and emphasize the need
Randomized trials to determine its cardiovascular safety profile,” the researchers wrote in the study.

Hidden danger?

Our bodies naturally produce melatonin. Among other things, the hormone helps regulate our sleep cycle.

In some countries such as the UK, officials have accepted a synthetic version of melatonin to treat insomnia in people over 55, while in the US, melatonin is widely available over the counter. Using melatonin for a night or two – say to beat jet lag – seems to be very safe in adults (though not in children). But scientists know little about its long-term safety, especially when it comes to the heart.

The authors analyzed data from the Trinetx Global Research network, a large, international database containing tens of thousands of medical records. They focused mainly on adults with chronic insomnia who had been prescribed melatonin for a year or more – about 60,000 people. They then matched this group to the same people who had insomnia but did not use sleep aids.

Over a five-year follow-up period, approximately 4.6% of melatonin patients developed heart failure, compared to 2.7% of non-melatonin patients – almost double. People on melatonin also had a higher risk of being hospitalized for heart failure and were almost twice as likely to die in general.

Roads and monitoring

The group’s findings are set to be presented this week at the American Heart Association’s annual scientific conference, but it carries some limitations.

The research is still in its infancy, and has not gone through the usual peer review process. It is retrospective and reversible, meaning it can only show a connection between chronic melatonin use and heart disease. And although the authors tried to control for important variables such as where the patient lived, there are potential limitations to the data.

The data used in the study covers many countries, including places like the US where melatonin is widely available over the counter. Because of this, the authors admit that it is entirely possible that some patients who were not melatonin-supplemented were taking the supplement without the findings.

This study far from smoking gun proves the dangers of chronic melatonin. But studies like these can make a case for descriptive research — randomized controlled trials — to find out for sure.