Melatonin, widely popular as an over-the-counter sleep aid, may pose unexpected risks to heart health. A new study presented at the American Heart Association (AHA) Scientific Sessions 2025 suggests a potential link between long-term melatonin use and an increased risk of heart failure hospitalization or death. While melatonin is often seen as a harmless solution for insomnia affecting millions of Americans, this research raises important questions about its safety for regular, extended use.
The study, led by Dr. Ekenedilichukwu Nnadi at Kings County Hospital and Downstate Health Sciences University in Brooklyn, followed over 130,000 adults with insomnia who had no history of heart failure. Researchers compared those who used melatonin regularly (for more than a year) to a similar group that didn’t use the supplement. The results were stark:
- Higher Heart Failure Risk: Individuals using melatonin long-term had a 90% higher chance of developing heart failure over five years compared to non-users.
- Increased Hospitalizations: They were nearly 3.5 times more likely to be hospitalized for heart failure (19% vs. 6.6%).
- Elevated Mortality: The melatonin group was almost twice as likely to die from any cause during the study period (7.8% vs. 4.3%).
These findings, while concerning, should be interpreted with caution. As Dr. Tamara Horwich, a cardiologist at UCLA, points out, the study cannot definitively prove causation. There might be other factors linked to both melatonin use and heart health issues, such as socioeconomic status or mental health conditions, that could explain the observed association.
“Melatonin may have beneficial effects on cardiovascular health in some cases,” Dr. Horwich adds, citing existing studies suggesting potential protection against heart failure and cardiomyopathy. More research is needed to disentangle these complexities.
The Accessibility Dilemma
Dr. Nnadi’s interest in this topic stemmed from his experience working with underserved communities where access to prescription sleep medications is often limited. “Because melatonin is inexpensive and widely available over the counter, it’s frequently the only option for my patients,” he explains. However, this accessibility comes with a potential trade-off if long-term use carries hidden risks.
Melatonin: Beyond Sleep Regulation
It’s important to remember that melatonin does more than just regulate sleep. Produced naturally by the pineal gland, it influences various bodily functions. Receptors for melatonin are present throughout the body, including in blood vessels. This means it can potentially interact with other medications and affect overall health in ways not yet fully understood.
The Bottom Line: A Conversation Worth Having
While melatonin is widely available and often perceived as a safe sleep aid, this research warrants further investigation into its long-term effects on the heart, especially for individuals with pre-existing risk factors. Before making melatonin a regular part of your bedtime routine, consult with your doctor. Discuss potential benefits and risks, explore alternative sleep strategies like improving sleep hygiene, and ensure melatonin doesn’t interfere with any other medications you may be taking. The goal is to find safe and effective ways to address sleep problems without compromising long-term health.
