Heart Health: Long-Term Melatonin Use Linked to Cardiovascular Risk

Melatonin has a very polished public image. It is the sleep supplement that sits on drugstore shelves looking calm, innocent, and vaguely lavender-scented, even when the bottle itself is bright neon gummy pink. Because it is sold over the counter and marketed as “natural,” many people assume it is automatically gentle, harmless, and perfectly fine to use night after night for months or years.

That assumption is exactly why the latest conversation around heart health and long-term melatonin use matters. A preliminary 2025 study presented at a major cardiology meeting linked extended melatonin use in adults with chronic insomnia to a higher risk of heart failure, hospitalization, and death over five years. That headline is serious. But the fine print matters just as much: the study showed an association, not proof that melatonin caused those outcomes.

So where does that leave people who take melatonin because they just want to sleep and not stare at the ceiling like it owes them money? In a place that calls for nuance. Melatonin is not automatically dangerous, but it is also not a magic bedtime vitamin. If you care about cardiovascular risk, it makes sense to look beyond the marketing, understand what the research actually says, and use melatonin more thoughtfully than many people do now.

Why This Story Is Suddenly Making Heart-Health Headlines

The biggest reason melatonin is back in the spotlight is a large observational study presented at the American Heart Association’s Scientific Sessions in 2025. Researchers reviewed five years of health records from more than 130,000 adults with chronic insomnia. Compared with matched non-users, people whose records showed melatonin use for at least a year had a noticeably higher likelihood of developing heart failure, along with higher rates of hospitalization for heart failure and a higher risk of death from any cause over the study period.

That sounds dramatic because it is dramatic. But it is also preliminary. The data were presented as a conference abstract, not as a full peer-reviewed paper. That means the findings deserve attention, not panic. Observational research can reveal a meaningful warning sign, but it cannot fully separate the effect of melatonin from the effect of the condition that led people to use it in the first place. Chronic insomnia itself is tied to poor cardiometabolic health, stress, blood pressure problems, and other factors that can muddy the picture.

In plain English: the study raises a fair question about melatonin and heart failure risk, but it does not deliver a final verdict.

What the Evidence Said Before This New Study

If you only read one headline, you might think the melatonin story is settled. It is not. Earlier research painted a much messier picture. Some short-term studies suggested melatonin may have beneficial effects on sleep timing, blood pressure patterns, oxidative stress, and other metabolic markers. A 2024 long-term prospective analysis of three large U.S. cohorts did not find a significant overall association between regular melatonin supplement use and cardiovascular disease in adults.

That does not cancel out the newer signal. It simply means the evidence is mixed. And mixed evidence is common in sleep medicine, especially when one product is being used by people with very different health profiles, doses, schedules, and reasons for use.

This is why a careful article on melatonin cardiovascular risk should avoid two extremes. The first extreme is “melatonin is totally harmless because it is natural.” The second is “melatonin is definitely bad for your heart.” Right now, neither statement is fully supported.

Why Long-Term Melatonin Use Could Matter for Heart Health

1. Sleep problems and heart problems already overlap

One reason this topic gets tricky is that poor sleep and poor heart health are already close cousins. People with chronic insomnia are more likely to have stress, depression, anxiety, elevated blood pressure, poor glucose control, and other issues that can raise cardiovascular risk over time. So when long-term melatonin users appear to have worse outcomes, part of the signal may come from the insomnia itself or from the health profile of people who rely on sleep aids regularly.

Still, that does not mean melatonin should get a free pass. It means researchers need better long-term data, especially studies that can sort out whether the supplement is a bystander, a marker of more severe sleep trouble, or an active contributor in some patients.

2. Blood pressure effects are not always simple

Melatonin is often discussed as though it only affects sleep. In reality, it interacts with circadian biology, and circadian biology reaches far beyond bedtime. Some clinical sources warn that melatonin may increase blood pressure in people taking certain hypertension medications. That does not mean everyone who takes melatonin will see their numbers rise, but it does mean people with hypertension should not treat it like an innocent piece of candy with a bedtime marketing budget.

If your heart health plan already includes blood pressure medication, adding melatonin without a conversation with your clinician is less “wellness routine” and more “tiny unplanned pharmacology experiment.”

3. Drug interactions can change the risk picture

Melatonin can interact with other medications, including anticoagulants, sedatives, certain antidepressants, seizure medicines, and some blood pressure drugs. That matters for the heart because cardiovascular patients are often already taking complex medication combinations. A supplement that looks small on the label can behave much bigger inside the body when it collides with the wrong prescription mix.

Melatonin may also increase drowsiness when used with other central nervous system depressants. That may sound more like a next-morning problem than a heart problem, but it matters. Fatigue, dizziness, and reduced alertness are not great companions for older adults, people with chronic illness, or anyone trying to manage a complicated medical routine.

The Supplement Aisle Has a Quality-Control Problem

One of the least glamorous but most important parts of this story is quality control. In the United States, melatonin is generally sold as a dietary supplement, not regulated like a prescription drug. Translation: the bottle is not always a perfect mirror of what is inside it.

That is not a theoretical concern. Published analyses of melatonin products have found that actual melatonin content can vary widely from the label, and some gummy products have contained inaccurate amounts or additional ingredients such as CBD. Earlier research also found substantial lot-to-lot variability and even contamination concerns in some products.

From a heart-health perspective, that matters a lot. If someone thinks they are taking a modest dose but the actual content is far higher, the real exposure over months or years may be quite different than expected. A supplement cannot be “low risk” in practice if the dose itself is playing hide-and-seek.

This quality issue is also part of why blanket reassurance makes no sense. Two people may both say, “I take melatonin every night,” but one could be taking a low, consistent dose from a verified product while the other is getting an unpredictable amount from a gummy that behaves like a chemistry pop quiz.

Who Should Be More Cautious About Long-Term Melatonin Use?

Not everyone faces the same level of concern. People who should be especially careful include:

• Adults with chronic insomnia who have been using melatonin for months without re-evaluating why they still need it.
• People with hypertension, cardiovascular disease, or multiple heart-risk factors such as diabetes, obesity, or a strong family history.
• Anyone taking blood pressure medication, blood thinners, sedatives, or other drugs known to interact with melatonin.
• Older adults, because melatonin may remain active longer and increase daytime sleepiness.
• People who keep increasing the dose because the original dose “stopped working.”

That last group deserves special attention. Once a sleep supplement becomes a nightly ritual, it can quietly shift from occasional tool to emotional security blanket. And security blankets are comforting, but they are not the same thing as a well-designed long-term treatment plan.

What Smarter Use Looks Like

If you use melatonin occasionally for jet lag, a temporary schedule change, or a short rough patch, that is a different scenario than taking it indefinitely for chronic insomnia. Several clinical sources frame melatonin as more useful for short-term or circadian-timing issues than as an endless fix for long-standing sleep trouble.

A practical approach looks like this: use the lowest effective dose, choose a more reliable product, avoid assuming “more is better,” and stop to reassess if it is not helping. Some sleep specialists suggest that if melatonin is not helping after a week or two, or if sleep problems keep returning, it is time to stop guessing and start investigating.

That investigation should include the basics many people skip because they are less exciting than supplements: caffeine timing, alcohol use, evening light exposure, screen habits, stress, anxiety, depression, sleep apnea, restless legs, medication side effects, and inconsistent sleep schedules. None of those come in a cute gummy, which may be why they get ignored. Unfortunately, they also happen to matter a lot.

For Chronic Insomnia, the Better Long-Term Strategy Is Usually Not More Melatonin

When sleep trouble becomes chronic, many experts recommend cognitive behavioral therapy for insomnia, often called CBT-I, as the first treatment to consider. That is not as flashy as grabbing a bottle off a shelf, but it has a major advantage: it aims to fix the patterns that keep insomnia alive instead of simply throwing a bedtime nudge at the problem and hoping for the best.

CBT-I can help people reset behaviors, thoughts, and routines that interfere with sleep. In many cases, it works as well as or better than sleep medications over the long haul. That matters for heart health because chronic insomnia is not just a sleep issue. It can become a stress issue, a blood pressure issue, a mood issue, and eventually a cardiometabolic issue.

So if someone has been taking melatonin every night for six months, a year, or longer, the right question may not be, “Should I switch brands?” It may be, “Why am I still unable to sleep, and what is the real treatment for that?”

Experiences People Commonly Describe With Long-Term Melatonin Use

The following experiences are illustrative composites based on common patterns clinicians discuss, not individual case reports.

One common experience is the “it started small” story. A person takes melatonin for jet lag, a stressful work week, or a stretch of late-night screen time. It works well enough at first, so they keep going. Weeks turn into months. Eventually the supplement is no longer a backup plan; it becomes part of the bedtime identity. They feel nervous skipping it, even if they are not sure it still helps much. The irony is that the ritual starts to feel stronger than the actual effect.

Another familiar pattern is the “dose creep” story. Someone begins with 1 milligram, then moves to 3, then buys a gummy with a bigger number on the front because sleep has gotten worse again. They wake up groggy, feel a little foggy in the morning, and assume they are just tired from poor sleep. Sometimes they never consider that the supplement itself might be contributing to the hangover feeling. Sometimes they also take other medications, which makes the whole picture blurrier.

There is also the “I thought natural meant harmless” experience. This person is careful with prescriptions but casual with supplements. They would never change a blood pressure medication without asking a doctor, yet they feel completely comfortable adding melatonin for months because it seems gentle and familiar. Then they learn that melatonin can interact with certain medications, that product content can vary, or that long-term safety is still not well defined. The mood is usually not panic. It is annoyance. Nobody loves discovering that the “easy” solution came with footnotes.

Some people describe a more emotional experience. They are not taking melatonin because they love supplements; they are taking it because insomnia is miserable. They are tired, frustrated, and maybe a little scared by how bad sleep affects mood, concentration, patience, and relationships. For them, melatonin becomes a symbol of trying. So when they hear that long-term use may carry potential heart-health concerns, the reaction is not simply medical. It is personal. They feel as though the one thing that seemed gentle might not be so gentle after all.

Then there is the best-case experience: the person who uses melatonin briefly, for a specific reason, at a modest dose, while also cleaning up their schedule, light exposure, caffeine timing, and bedtime habits. They stop once the issue passes. No drama. No dependence on the routine. No supplement taking up permanent residency on the nightstand like a tiny, bossy landlord. That experience probably deserves more attention, because it reflects what melatonin may be best suited for: targeted, thoughtful, short-term use rather than open-ended sleep management by default.

Final Takeaway

The phrase “long-term melatonin use linked to cardiovascular risk” is compelling, but the smartest reading is a careful one. The newest study raises a real concern, especially around heart failure in adults with chronic insomnia. At the same time, the evidence is not yet strong enough to say melatonin directly causes cardiovascular harm in the general population.

What is clear is this: long-term melatonin use should not be treated as casual, consequence-free self-care. The supplement is widely used, product quality can vary, interactions are possible, and the long-term safety picture is still incomplete. If you have ongoing sleep problems or any meaningful heart-health risk, the better move is not blind faith in a bedtime gummy. It is a thoughtful conversation with a clinician, a closer look at the reason you are not sleeping, and a treatment plan that supports both better rest and better cardiovascular health.