- Researchers say people with insomnia who use melatonin supplements for more than a year have a higher cardiovascular disease risk than people with insomnia who donโt use the sleep aid.
- Experts say the research raises some important questions, but they note that the study does not directly link melatonin to the cause of the heart disease risks.
- They add that melatonin is intended for short-term use, and there are ways for a person to obtain good quality sleep without taking medication.
Researchers are reporting that long-term use of melatonin supplements may increase the risk of heart failure.
In theirย study, the researchers said that people who used melatonin for more than a year were more likely to be diagnosed with heart failure, require hospitalization for that condition, or die from any cause.
Their research is being presented later this week at the American Heart Associationโsย Scientific Sessions 2025ย meeting in New Orleans.
The preliminary study has not yet been published in a peer-reviewed scientific journal.
Researchers acknowledged their study doesnโt establish a cause-and-effect relationship between melatonin supplements and heart failure risks.
However, they noted that the results raise safety concerns about the long-term use of melatonin and, therefore, may warrant further research on these supplements to assess their cardiovascular safety.
Researchers also noted that many melatonin supplements are sold over-the-counter without a prescription. They said these products are not regulated, and people can use them without the guidance of a healthcare professional.
โMelatonin supplements may not be as harmless as commonly assumed. If our study is confirmed, this could affect how doctors counsel patients about sleep aids,โย Ekenedilichukwu Nnadi, MD, the lead author of the study and the chief resident in internal medicine at SUNY Downstate/Kings County Primary Care in Brooklyn, NY, said in aย news release.
Experts who werenโt involved in the study said the research raises some serious questions, although they add itโs important to note the study does not directly link melatonin to cardiovascular disease risk.
โThe study raises some important and unexpected concerns,โ saidย Rigved Tadwalkar, MD, a consultative cardiologist and director of the Digital Transformation Pacific Heart Institute in Santa Monica, CA. โItโs interesting because melatonin has been thought of as being heart-protective.โ
โThe results are quite striking,โ added Cheng-Han Chen, MD, an interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, CA. โThat being said, an association (with risks) is different than a causation.โ
Melatonin and heart health risks
Melatoninย is a hormone produced in the body by the pineal gland. It helps regulate the bodyโs sleep-wake cycle. Melatonin levels increase during darkness and decrease during daylight hours.
Melatonin supplements are chemically identical synthetic versions of the hormone. They are often used to treatย insomnia, a condition characterized by difficulty falling asleep, staying asleep, or waking up too early.
Itโs estimated that about one-third of people in the United States donโt get the recommended 7 hours of sleep per night. About 10% of Americans haveย chronic insomnia, in which they have sleep difficulties at least three times a week over a 3-month period.
Pastย researchย has indicated that melatonin can be beneficial in helping people sleep as well as assist in correcting jet lag, improving eye health, and offering pain relief to individuals with migraine.
However, researchers in the new study said data have been lacking on melatoninโs long-term cardiovascular safety. That prompted them to examine whether melatonin use might increase the risk of heart failure, specifically in chronic insomnia patients.
Their study was done over the course of 5 years. The researchers utilized the TriNetX Global Research Network, a large international database established in 2013.
The researchers looked at the electronic health records in the database of more than 130,000 people. The average age of the subjects was 55 years. More than 60% were women.
They divided participants into two groups: People with insomnia who had used melatonin supplements for at least a year and participants with insomnia who had no record of utilizing these supplements.
There were about 65,000 people in each of the groups.
None of the people studied had been previously diagnosed with heart failure or had been prescribed sleep medications other than melatonin.
The researchers reported that the subjects who used melatonin for more than a year had a 90% higher chance of incident heart failure over 5 years compared to people who didnโt use the sleep aid.
Participants taking melatonin were also nearly 3.5 times as likely to be hospitalized for heart failure when compared to those who didnโt use melatonin supplements.
In addition, people in the melatonin group were nearly twice as likely to die from any cause when compared to the non-melatonin group.
Tadwalkar noted that one reason for these figures may be that people with chronic sleep issues may face health risks associated with that condition, regardless of whether they take melatonin.
โThis might be a guilt-by-association type of situation,โ he told Healthline.
Chen said melatonin was designed as a short-term treatment. He said people who need to take the sleep aid for more than a year could have other serious underlying issues.
โThey probably should go see a sleep specialist and try to figure out whatโs going on,โ he told Healthline.
Benefits of quality sleep
Experts say that getting the recommended 7 or more hours of sleep per night offers numerous health benefits.
Sleep is listed as one of the key components of the American Heart Association (AHA)โsย Lifeโs Essential 8ย healthy habits.
According to the Centers for Disease Control and Prevention (CDC),ย quality sleepย can enhance overall health in several ways. These include:
- stronger immune system
- healthy weight maintenance
- improved heart health and metabolism
- reduced risk of chronic conditions (i.e., type 2 diabetes)
- improved memory and cognition
- reduced stress and improved mood
On the other hand, a lack of consistent quality sleep can lead to health risks, including high blood pressure, stroke, heart attack, and heart disease.
Chen and Tadwalkar both said the health risks from poor sleep probably outweigh the potential risks from melatonin use.
โPoor sleep can put a lot of stress on the heart,โ noted Chen.
โInadequate sleep is a major cardiovascular risk,โ added Tadwalkar. โChronic insomnia is a huge red flag.โ
Tips to help you sleep better
There are several thingsย you can do to achieve quality sleep without medication. Among them:
- getting bright light exposure during the day
- reducing blue light exposure at night
- avoiding caffeine late in the day
- avoiding alcohol late in the day
- avoiding late meals
- exercising during the day but not at night
- having a comfortable bed and pillow
- going to bed and waking up at the same time every day
Tadwalkar added thatย cognitive behavioral therapy (CBT)ย has also been shown to beย beneficialย by addressing thoughts, behaviors, and habits associated with poor sleep.
Both experts encouraged going to bed in a dark, cool, quiet room and avoiding caffeine, alcohol, and electronic screens in the evenings.
โSleep hygiene practices are so important,โ Tadwalkar said.
