Melatonin and Heart Disease: What the New Study Really Means (And Why You Shouldn't Panic)
You've probably seen the headlines by now: "Melatonin Linked to Heart Failure" or "Popular Sleep Supplement Increases Death Risk." If you're one of the millions of Americans who reach for a melatonin supplement at bedtime, you might be feeling pretty anxious right about now.
Take a breath. Before you toss your bottle in the trash, let me walk you through what this study actually found—and more importantly, what it didn't find.
The Study Everyone's Talking About
Researchers analyzed five years of electronic health records for over 130,000 adults with chronic insomnia. They compared people who had used melatonin for at least a year with people who never had melatonin documented in their medical records.
The findings sound alarming at first glance:
People in the melatonin group had a 90% higher chance of developing heart failure (4.6% versus 2.7%)
They were 3.5 times more likely to be hospitalized for heart failure (19% versus 6.6%)
They were nearly twice as likely to die from any cause during the five-year period (7.8% versus 4.3%)
Scary, right? But before you panic, let's talk about what's really going on here.
The Major Flaw That Changes Everything
Here's the critical detail that most headlines completely buried: this study has a significant methodology problem that could invalidate the entire thing.
The researchers used a global database that included countries where melatonin requires a prescription (like the United Kingdom) AND countries where it's available over-the-counter (like the United States). But they could only track melatonin use through what was documented in medical records—meaning prescriptions.
So here's what that means in practice: Every single American walking into CVS, Walgreens, or Target to buy melatonin off the shelf? They were counted in the "non-melatonin group." Only people with documented prescriptions appeared as "melatonin users" in the data.
Think about why someone would need a prescription for melatonin in the UK versus why someone in the US might grab it casually from the supplement aisle. The prescription group likely represents people with severe, chronic, treatment-resistant insomnia—a completely different population than casual users.
The study essentially compared people with severe insomnia (prescription group) to a mixed group that included healthy sleepers, people with mild sleep issues, AND casual melatonin users who weren't captured in the data. That's not comparing apples to apples—that's comparing apples to a fruit basket.
This Study Hasn't Been Peer-Reviewed
Here's another crucial detail: this research is a preliminary abstract presented at the American Heart Association's Scientific Sessions conference. It has not been peer-reviewed or published in a scientific journal yet.
That doesn't mean the findings are worthless, but it does mean they haven't been scrutinized by other scientists who could identify flaws, ask critical questions, or challenge the conclusions. The American Heart Association even notes in their press release that "findings are considered preliminary until published as full manuscripts in a peer-reviewed scientific journal."
What This Study Actually Tells Us (And What We Already Knew)
Okay, so if the study has major flaws, does that mean there's nothing to learn here? Not at all.
What this research actually confirms is something we've known for a long time: chronic insomnia is devastating to your cardiovascular health.
When you're not sleeping night after night, month after month, year after year, here's what happens to your body:
Your blood pressure stays elevated. Normally, blood pressure drops during sleep—it's called "nocturnal dipping," and it gives your cardiovascular system a crucial break. Research published in Hypertension shows that people who don't experience this nighttime blood pressure reduction have significantly higher rates of cardiovascular disease. When you're lying awake at 3 AM night after night, you're missing out on this protective mechanism.
Stress hormones remain chronically elevated. Your cortisol levels should naturally decline in the evening and stay low overnight. But chronic insomnia keeps your body in a state of hyperarousal, with cortisol remaining elevated when it should be at its lowest. A study in the Journal of Clinical Endocrinology & Metabolism found that people with insomnia have significantly higher 24-hour cortisol levels, which directly contributes to cardiovascular disease risk.
Inflammation runs rampant. Poor sleep triggers the release of pro-inflammatory markers like C-reactive protein (CRP) and interleukin-6 (IL-6). Research in Sleep Medicine Reviews demonstrates that chronic sleep deprivation creates a state of systemic inflammation that damages blood vessels, promotes atherosclerosis, and increases the risk of heart disease.
Your autonomic nervous system stays stuck in "fight or flight." Quality sleep allows your parasympathetic nervous system (the "rest and digest" mode) to dominate, giving your heart rate and blood pressure a chance to recover. Chronic insomnia keeps you in sympathetic overdrive, which is exhausting for your cardiovascular system.
So yes, the association between sleep problems and heart disease is real and well-established. But it's the chronic insomnia itself—not the melatonin—that appears to be the culprit.
The Melatonin Question: Are You Treating the Symptom or the Cause?
Here's where I want to shift gears and talk about what I see in my practice every single day.
I've been there, remember? I spent years waking up at 3 AM like clockwork, trying everything from meditation apps to (embarrassingly) my dog's Trazodone. When conventional medicine only offered sleeping pills and an anxiety diagnosis, I knew something deeper was going on.
It wasn't until I discovered functional lab testing that everything changed. Turns out, my insomnia wasn't just "in my head"—my gut was a disaster, my neurotransmitters were imbalanced, I had significant nutrient deficiencies that conventional blood work completely missed, plus thyroid issues, Hashimoto's, and copper toxicity.
And here's what I've discovered through testing hundreds of clients: most people taking melatonin every night aren't actually deficient in melatonin.
Let me explain why this matters.
The Gut-Melatonin Connection Nobody's Talking About
Your body naturally produces melatonin—it's not something you're supposed to need from a bottle every night. Here's the process:
Your gut produces about 95% of your body's serotonin (not your brain, despite what most people think). That serotonin is then converted into melatonin in your pineal gland when darkness signals it's time for sleep.
So if you're not making enough melatonin naturally, the question isn't "should I take more melatonin?" The question is "why isn't my body producing it?"
Usually, the answer lies in one of these areas:
Gut health problems. If your gut microbiome is imbalanced, inflamed, or damaged, you're not producing adequate serotonin in the first place. Research in Cell shows that specific gut bacteria are essential for tryptophan metabolism and serotonin production. No healthy gut bacteria, no serotonin. No serotonin, no melatonin.
Chronic inflammation. An inflamed gut triggers systemic inflammation that keeps your nervous system on high alert. A study in Neuroimmunomodulation found that inflammatory markers directly inhibit melatonin production and disrupt your circadian rhythm.
Nutrient deficiencies. Your body needs specific nutrients to convert tryptophan to serotonin to melatonin—including magnesium, vitamin B6, vitamin D, and zinc. If you're deficient (and conventional lab work often misses this), you're not making melatonin efficiently.
Hormonal imbalances. For women in perimenopause and menopause, declining estrogen directly impacts serotonin production. Research published in Menopause shows that estrogen regulates tryptophan hydroxylase, the rate-limiting enzyme in serotonin synthesis. When estrogen drops, so does serotonin—and subsequently, melatonin.
This is exactly why taking melatonin every night is like putting a band-aid on a broken bone. You're treating the symptom without addressing why your body stopped producing melatonin in the first place.
What You Should Do If You're Taking Melatonin Regularly
First, don't panic and don't suddenly stop taking it if it's helping you sleep. Remember, this study has significant limitations and hasn't been peer-reviewed.
But if you've been reaching for melatonin every single night for months or years, it's time to ask yourself: why?
Here's what I recommend:
Get curious about the root cause. Instead of accepting that you "just have insomnia," dig deeper. What's actually disrupting your sleep? Is it gut issues? Hormonal imbalances? Nutrient deficiencies? Chronic stress that dysregulates your nervous system?
Consider functional lab testing. This is different from conventional blood work. Functional testing looks at optimal ranges (not just "normal" ranges) and can identify imbalances that standard labs miss completely. I use tests that assess gut health, hormone levels, nutrient status, and more—because testing is better than guessing.
Address your gut health. Start with the basics: eliminate inflammatory foods, add fermented foods to support your microbiome, consider a high-quality probiotic. But ideally, test first so you know exactly what you're dealing with.
Support your hormones naturally. For women in midlife, this might mean working with a practitioner who understands hormone replacement therapy, or using targeted supplements to support declining estrogen and progesterone.
Regulate your nervous system. If you're stuck in chronic stress mode, your body won't shift into the parasympathetic state needed for sleep. Techniques like vagal toning, breathwork, and mindfulness can make a massive difference.
Use melatonin strategically, not chronically. Melatonin can be helpful for short-term use—jet lag, shift work, occasionally resetting your circadian rhythm. But it shouldn't be your nightly crutch for months or years on end.
The Real Takeaway From This Study
So what should you actually take away from this melatonin and heart disease research?
It's not that melatonin is dangerous and you should never touch it. It's that chronic insomnia itself is incredibly damaging to your cardiovascular health—and your overall health.
If you're relying on any sleep aid every single night for extended periods, whether it's melatonin, prescription medication, or anything else, that's a red flag telling you something deeper is wrong.
Your body is designed to sleep. When it can't, there's always a legitimate reason. We've just got to find it.
I've been there, remember? Years of 3 AM wake-ups, feeling like a hypocrite as a sleep consultant who couldn't fix her own sleep, stealing my dog's medication out of desperation. But it wasn't until I stopped masking the symptoms and started addressing the root causes that everything changed.
Six months of functional health work transformed my sleep—and my life. I got my energy back, my joy back, my patience with my family back. I finally felt like myself again.
And now, it's my mission to help other women—especially those in the prime of their lives dealing with perimenopause and menopause—find that same relief.
Ready to Stop Guessing and Start Sleeping?
If you've been taking melatonin every night and you're tired of just masking the problem, let's figure out what's really keeping you awake.
Through comprehensive functional lab testing and personalized protocols, we can identify the specific imbalances disrupting your sleep—whether it's gut issues, hormonal chaos, nutrient deficiencies, or nervous system dysregulation.
Because here's what I know for sure: there's always a reason you're not sleeping. Once we find it, the solution becomes clear.
Book a free discovery call and let's uncover your sleep saboteurs together. You don't have to accept sleepless nights as your new normal—and you definitely don't have to rely on supplements every night for the rest of your life.
Testing is better than guessing, my friend. Let's figure out your sleep puzzle.
For daily sleep tips and guidance, follow me on Instagram @kellymurrayadultsleep!
Sweet Dreams…
Kelly Murray is a certified sleep coach and an award-winning pediatric sleep consultant based in Chicago offering sleep coaching services nationwide.