How Melatonin Impacts Heart Health

If you’re dealing with insomnia and you’ve taken melatonin as a sleep aid, you’re not alone. It’s a popular over-the-counter supplement that many people swear by. But recent rumblings about its safety for your health might be making you toss and turn.

It’s important to clear up one thing right off the bat: There are currently no proven links between melatonin supplements and heart disease or problems. So, you can rest a little easier if you’ve been worried.

But that doesn’t mean melatonin is risk-free — or even the right solution for your needs.

Cardiologist Michael Hill, MD, walks us through the research.

Does melatonin use cause heart failure?

There’s no clear evidence that melatonin causes heart failure.

So, why the chatter? It’s because researchers found possible links between melatonin and heart failure. They used a health records database to compare two groups of adults with insomnia — those who took melatonin for at least one year, and those who didn’t.

They found that within a five-year period, the melatonin group had higher rates of:

• Heart failure
• Hospitalization for heart failure
• Death from any cause

“These are striking findings, and that’s why they made headlines,” Dr. Hill acknowledges. “But there are some important caveats.”

Dr. Hill explains:

• There’s no proof that melatonin caused heart failure: The research makes associations, but it doesn’t prove causation. That’s a huge distinction. It means there are patterns, but there’s no proof that melatonin is the driving factor.
• The findings aren’t peer-reviewed: “This is a research abstract, meaning a presentation of preliminary data,” Dr. Hill notes. “It must go through rigorous peer review before we accept the findings as fact.”
• Gaps remain: Because these are early findings, we don’t know the factors, like melatonin supplement dosage or treatments given to the non-melatonin group. We also don’t know if some people had sleep apnea or other diagnoses.
• Heart failure can cause sleep issues: It’s possible that some study participants had issues because they were already in the early stages of heart failure and didn’t yet have a diagnosis. That would add more gray area to the findings.

“Based on the information available so far, we can’t say that melatonin causes heart failure,” Dr. Hill clarifies. “But the topic is on our radar, and we’ll continue learning.”

Can it cause other heart issues?

There’s not enough evidence to say that melatonin causes other problems, like heart palpitations or an increased heart rate.

One study from 2017 found possible associations between melatonin use and premature ventricular contractions (a common and typically harmless arrhythmia). But that study only looked at two adults. We’d need much more evidence to prove any links.

Why you might be feeling palpitations

So, if you’re taking melatonin and notice your heart racing, skipping a beat or flip-flopping, what’s up? Dr. Hill offers insight.

“Palpitations or an increased heart rate may be due not to the melatonin, but rather to sleep apnea,” he says. “This common disorder is associated with both slow or fast abnormal heart rhythms and irregular beats, which can cause those unusual sensations.”

Many people don’t even realize they have sleep apnea. But red flags include waking up tired every morning and needing naps to get through the day. If this sounds familiar, talk to a healthcare provider — especially if you’re noticing palpitations.

Possible benefits of melatonin for your heart

Now that we know there aren’t proven risks, you may be wondering: Can melatonin do your heart any good? Maybe, according to some evidence.

“Some randomized clinical trials have shown possible benefits of melatonin,” Dr. Hill shares. He notes that in a randomized trial of people with heart failure, those taking melatonin for six months saw improvements in:

• Symptoms
• Quality of life
• A blood marker called NT-proBNP (which usually reflects heart failure symptom burden)

“While this is a small study, it offers high-quality evidence that warrants further research,” he adds.

That’s right — some findings seem to contradict the research abstract! This might feel confusing. But that can be the nature of medical research. There’s not a single path going in one direction. Researchers explore all avenues to learn as much as they can, even if that means grappling with conflicting data.

“Another study has found possible links between melatonin and reduced blood pressure and cholesterol levels,” Dr. Hill says. “Melatonin likely isn’t the direct cause. But it could be helping you sleep better. And that, in turn, helps manage your blood pressure, cholesterol and other heart disease risk factors.”

Better sleep lowers cardiovascular disease risk

It’s a well-established fact that better sleep translates to a lower risk of heart and blood vessel problems. The opposite is also true — poor sleep raises your risk of cardiovascular disease.

Sleep is so important that the American Heart Association lists “get healthy sleep” as one of “Life’s Essential 8” measures for improving cardiovascular health. These are eight steps we all should try to take to protect our hearts.

But good sleep can be hard to come by. Enter melatonin. It may help shift your body’s circadian clock so you sleep soundly and wake up feeling rested.

If melatonin helps you sleep better, that’s great. But Dr. Hill cautions that it’s not meant for long-term use.

Short-term use is best

“Melatonin is best used on a temporary basis,” Dr. Hill emphasizes. “If you’ve needed it for months or years to achieve good quality sleep, talk to your primary care provider or even a sleep specialist.”

Dr. Hill describes why limited use is best:

• Melatonin may mask the reason for poor sleep. Taking melatonin as a sleep aid may help you snooze, but it won’t reveal the root cause of sleep issues. And that means you may go months or years without effective treatment for sleep apnea, insomnia or other conditions.
• Long-term melatonin use may not be safe. “Less is known about the risks of long-term supplementation,” Dr. Hill states. “So, it’s a good idea to limit use to temporary situations, like when you’re traveling or trying to adjust your bedtime.”
• Melatonin supplements aren’t regulated. In the U.S., melatonin is an over-the-counter supplement, not a prescription drug. That means the U.S. Food and Drug Administration (FDA) doesn’t regulate its dosage or quality.

Talk with your doctor about safety

If you decide to use melatonin, talk with a healthcare provider first. They’ll make sure:

• It’s safe for you based on your health history.
• It won’t interact with any medications you’re taking.
• You’re aware of possible side effects, like dizziness, headaches and daytime drowsiness.

“Some research shows that melatonin may adversely affect blood sugar variations in people with diabetes,” Dr. Hill warns. “That’s just one example of a scenario where we’d want to be extra careful in using melatonin, even just for a few days.”

Make quality sleep a priority

Whether or not you’re taking melatonin, one thing’s for sure: Sleep is vital for your heart.

If a good night’s sleep feels like an impossible dream, it’s time to talk to a healthcare provider about treatment options. They’ll go over the possible causes, from excess stress, circadian disruptions and poor sleep hygiene to diagnosable conditions like sleep apnea or insomnia.

“There’s no need to toss out your melatonin based on any of this latest research,” he says. “But ideally, it’ll mostly stay in your cabinet. Work with your provider to find sustainable, long-term solutions to the sleep issues you’re facing.”