Melatonin is having a moment right now, but not in the good way. A few months ago, a big study made headlines for linking melatonin use to heart-related complications, like higher risk of heart failure, more heart-related hospitalizations, and even higher mortality. And it’s a perfect example of how a headline can take a complicated study and turn it into something much scarier than what the data actually shows.
.webp "The REAL Problem With Melatonin (It's Not Heart Failure)")
So, in this article, I want to unpack this in a way that actually makes sense, and I want to help you decide how you should approach melatonin. And this is not to say melatonin is good or bad, because melatonin has real problems. They just have nothing to do with heart failure. The real issues come from how people use it and the doses they take and the misleading and inaccurate dosing labels on many melatonin products, even if you get them from reputable brands.
And at the end of the article, I’m going to give you a simple framework for improving your sleep that does not depend on melatonin at all, because most people turn to melatonin for a sleep problem it was never designed to fix. I’m Dr. Lenny F. Kam, and on this channel, I go over the most up-to-date and evidence-based information on topics of weight loss, metabolic health, and longevity. Let’s get into it.
The Study That Made the Headlines
Now, let’s talk about the study that made the headlines, because on the surface, it looks pretty worrisome. So, the researchers pulled 5 years of electronic health records, and they look at the data from more than 130,000 adults. And what they found was in the people who had melatonin recorded in their medical chart, well, that group had an 89% higher risk of heart failure.
And that group also had a threefold increase in heart-related hospitalization. And they had double the risk of all-cause mortality, which means death from any cause. But, here’s the problem. This was an observational study, and as we always talk about, an observational study cannot prove causation. You can only show an association between melatonin use and these outcomes.
Why the Results Are Hard to Interpret
And here are the most glaring problems, making it very difficult to interpret these results. So, the first problem is how they identify melatonin users. The study looked at people who had melatonin documented in their chart. But, in the US and many other countries, melatonin is an over-the-counter medication. So, it wouldn’t show up in the medical record unless a clinician asked about it or a patient mentions it, which means that some people in the non-melatonin group were also probably taking melatonin without it being documented.
And the people who did show up in the melatonin group were likely the ones who had more severe or persistent sleep problems. And that matters because we have a lot of data from observational studies, but more importantly, also from Mendelian randomization studies where they did establish a causal link between short sleep duration and increased risk of heart failure.
So, the question becomes, is it the melatonin that’s causing these heart issues or is it the underlying insomnia? And when you look at the totality of the available evidence, well, melatonin looks more like an innocent bystander. It’s a marker that someone has poor sleep, but probably not the cause of their problems.
What Randomized Controlled Trials Show
And we see this clearly when we look at the randomized controlled trials. There was a recent systematic review and meta-analysis of four randomized controlled trials in patients with heart failure. And in those trials, melatonin did not harm the heart. It actually improved the quality of life and functional status.
And people taking melatonin also had less fatigue and they showed improvements in their markers related to their heart failure.
The Real Problem With Melatonin: Dosing
Now, let’s shift to the melatonin story that almost never makes the headlines. But, this particular problem is why I rarely recommend melatonin to my patients. The biggest problem is the dosing.
Most People Take Too Much
And the first part is simple. Most people take way too much melatonin. Our brains naturally produce about 20 to 40 micrograms of melatonin per night, not milligrams, micrograms. But, most products, at least in the US, come in the doses of 3 mg or 5 mg or even 10 mg doses, which means you may be giving your body a dose that is multiple times higher than anything your body would ever make on its own.
And when you stack that dose on top of your brain’s natural melatonin release, well, you can end up with levels that stay elevated well into the next morning. So, that’s why so many people can feel groggy or sluggish after taking melatonin the night before. They simply just have way too much melatonin when they wake up.
Labels Are Often Inaccurate
But, the next part of the problem is even bigger, and it has to do with what’s actually inside the bottle. There was a study published in the Journal of Clinical Sleep Medicine that tested common melatonin products. I think they tested at least 31 different brands of melatonin, and how much melatonin was in individual pill compared to what was written on the label was all over the place.
Some had 80% less melatonin than what the label claimed, and others had up to 500% more. A quarter of the melatonin pills they tested also contained serotonin, which should not have been there at all. And these weren’t obscure supplement companies. You see this mismatch between the label and the actual dose even in very reputable brands.
And there’s a reason it keeps happening. Melatonin is an unstable compound, and it tends to degrade and break down over time. So, the potency slowly drops as the bottle sits on the shelf. And the current US regulations require supplements to deliver at least the labeled dose by the expiration date, which is usually two to three years after manufacturing.
So, the brands that are trying to stay compliant with the regulations often add extra melatonin at the start to make sure that the product still meets the label years later. And in real life, that means if a bottle says it contains 5 mg of melatonin, a freshly produced pill might actually have seven or eight or even 9 mg of melatonin.
Now, this higher dose gradually decreases over its shelf life and eventually lands on the correct 5 mg dose near the expiration date. So, the problem that we’re running into is most people are already taking doses far higher than what the brain naturally produces. And on top of that, the actual dose in the pill can vary from bottle to bottle.
And all of this makes it very hard for your body to respond in a predictable and consistent way.
Melatonin Is Not a Sleep Hormone
Which brings me to the last major reason I don’t typically recommend melatonin as a long-term treatment for insomnia. Melatonin is a hormone, but it’s not a sleep hormone the way most people imagine. It has no sedating property. It doesn’t knock you out or make you sleepy.
What melatonin really does is it shapes your circadian rhythm. It tells your brain that it’s night time and it helps your body line up with the light dark cycle. So, the way to look at it is melatonin is not your body’s sleep switch. It’s just your body’s “Oh, it’s dark outside” signal. And that’s important because most people who struggle with sleep are not struggling with that signal.
What Most People Are Actually Struggling With
What they’re struggling with is something completely different. Most people with insomnia, they know it’s late and they know they need to sleep. Their circadian rhythm is usually just fine. Their real problem is conditioned wakefulness or conditioned arousal. Now, obviously there’s many causes for insomnia, especially insomnia when it comes to initiating sleep or having trouble falling asleep.
But, for the vast majority of people, it’s happening because their brain has learned to associate the bed with wakefulness or stress. So, even when the clock says it’s time for bed, the nervous system just stays activated. And melatonin does nothing to shut that system down. It doesn’t lower arousal and it doesn’t calm the stress response.
And it doesn’t override the learned association between bedtime and being awake. All melatonin does is it simply reinforces the night time cue, which is not the part that is broken for most people.
A Simple Framework for Better Sleep Without Melatonin
Now, if melatonin isn’t the solution for most people, what actually helps? Well, let me give you a simple framework for improving your sleep that doesn’t involve any supplements or any medications.
The truth is sleep gets better when you line up your rhythm and your environment and your nervous system. And you don’t need any complicated routines to do that. All you need is just a few consistent habits and that’s what makes the biggest difference.
Start Your Sleep Routine in the Morning
So, first, your sleep routine actually starts in the morning. It helps to wake up at the same time every day, even on weekends.
Now, ideally, we go to bed and wake up at the same time, but we can’t always control when we fall asleep, but we can control when we get up. And a consistent wake-up time basically anchors your entire circadian rhythm. And as you wake up, you need to get outdoor light within the first 30 minutes of the day.
Morning sunlight shuts off melatonin production and it resets your clock and it sets the timing for the next night’s sleep. Your indoor lighting is just not strong enough to do the job. And if you’re waking up before sunrise, well, then I would talk to your doctor about a light therapy lamp that has a brightness of at least 10,000 lux.
Watch Caffeine, Alcohol and Meals During the Day
Next, as you go through your day, I would avoid caffeine at least 12 hours before bed. Caffeine has a pretty long half-life. So, if you drink it past noon, a lot of it will still be floating around in your system when it’s time to sleep. And I would also be careful with alcohol because alcohol disrupts the quality of your sleep.
And it does so by fragmenting your sleep and increasing nighttime awakenings. And it also increases your nighttime urination. So, alcohol can make you feel drowsy, which is why a lot of people drink alcohol actually, but it prevents the deep and restorative sleep that your body needs.
Next is I would try to front-load your calories earlier in the day. A solid breakfast with good protein and good fiber will help stabilize your glucose and energy for the rest of the day. And this will help you avoid larger meals at bedtime because if you eat too much for dinner, all that extra digestion that’s required will keep your body in this day mode, which makes it more difficult to fall asleep and stay asleep.
And I would also try to stop drinking fluids at least 2 to 3 hours before bedtime so that you’re not waking up at night to use the bathroom.
Give Yourself a Real Wind-Down
Now, as you get closer to bedtime, give yourself a real wind-down. Most people start this wind-down process way too late and expect the brain to go from full speed to sleep in minutes. And that rarely works.
So, I would start dimming your lights an hour before bed. And I would try to use more orange or red tone light if you need some kind of lighting. Because blue lights from our regular light bulbs or from TVs or electronics, well, they signal daytime to the brain, which will then make it more difficult to fall asleep.
And it’s not just the light, it’s the stimulation as well. So, reading the news or scrolling social media or checking work emails, all of that keeps your brain active at the exact time you want it settling down. So, instead, build a simple wind-down routine, something quiet and predictable. So, things like light stretching or slow breathing or meditation.
You can even read a paper book. Anything that signals to your brain that your day is ending. And if your mind tends to race at night, this is a good time to write things down. You can keep a journal where you just jot down a list of worries or a short plan for tomorrow. Another good exercise is writing down three good things that happened to you today.
Putting your thoughts on paper helps your brain stop rehearsing them when you’re trying to fall asleep. And another thing that can be part of your routine is a warm shower or a bath about an hour before bed. That will raise your core body temperature, and the cooling that happens afterwards tricks your brain into falling asleep faster.
It’s a small cue, but it works with your physiology, not against it.
Keep Your Bedroom Cool, Dark and Quiet
And then try to keep your bedroom cool and dark and quiet. It’s all about sleep associations and minimal distractions. So, you want your brain to associate your bed with sleep and nothing else. Now, if you follow all these steps, that will work far better than any supplement or medication.
And I realize this may require quite a few changes to your normal routine, but this is what addresses the root cause of the problem. This framework isn’t easy, but it is simple and it’s well worth the effort.
Frequently Asked Questions (FAQ)
Does melatonin cause heart failure?
The headline study linked melatonin use to an 89% higher risk of heart failure, a threefold increase in heart-related hospitalization and double the risk of all-cause mortality. But it was an observational study, which cannot prove causation. Melatonin looks more like an innocent bystander, a marker that someone has poor sleep, but probably not the cause of their problems.
Why is the melatonin heart failure study hard to interpret?
Melatonin is an over-the-counter medication, so it would not show up in the medical record unless a clinician asked about it or a patient mentioned it. Some people in the non-melatonin group were probably taking it without it being documented. The people in the melatonin group were also likely the ones with more severe or persistent sleep problems, and short sleep duration has been causally linked to a higher risk of heart failure.
What do randomized controlled trials say about melatonin and the heart?
A systematic review and meta-analysis of four randomized controlled trials in patients with heart failure found that melatonin did not harm the heart. It actually improved quality of life and functional status, and people taking melatonin had less fatigue and improvements in their heart failure markers.
How much melatonin does the brain make naturally?
Our brains naturally produce about 20 to 40 micrograms of melatonin per night. Most products in the US come in doses of 3 mg, 5 mg or even 10 mg, which is multiple times higher than anything your body would make on its own.
Why do I feel groggy after taking melatonin?
When a high dose is stacked on top of your brain’s natural melatonin release, levels can stay elevated well into the next morning. That is why many people feel groggy or sluggish, because they simply have too much melatonin when they wake up.
Are melatonin labels accurate?
Not always. A study published in the Journal of Clinical Sleep Medicine tested at least 31 brands and found that some had 80% less melatonin than the label claimed and others had up to 500% more. A quarter of the pills also contained serotonin. Melatonin degrades over time, so brands often add extra at the start to meet the label by the expiration date, which means a fresh pill labeled 5 mg might contain seven or eight or even 9 mg.
Is melatonin a sleep hormone?
Not the way most people imagine. It has no sedating property and does not knock you out or make you sleepy. It shapes your circadian rhythm and works as your body’s “Oh, it’s dark outside” signal.
What is the real problem for most people with insomnia?
Their circadian rhythm is usually fine. The real problem is conditioned wakefulness or conditioned arousal, where the brain has learned to associate the bed with wakefulness or stress. Melatonin does not lower arousal, calm the stress response or override that learned association.
Why is morning light important for sleep?
Getting outdoor light within the first 30 minutes of the day shuts off melatonin production, resets your clock and sets the timing for the next night’s sleep. Indoor lighting is not strong enough to do the job. If you wake up before sunrise, talk to your doctor about a light therapy lamp with a brightness of at least 10,000 lux.
What habits help improve sleep without supplements?
Wake up at the same time every day, get outdoor light early, avoid caffeine at least 12 hours before bed, be careful with alcohol, front-load your calories earlier in the day, and stop drinking fluids 2 to 3 hours before bedtime. Start dimming your lights an hour before bed, build a quiet wind-down routine, and keep your bedroom cool, dark and quiet.
Conclusion
The headlines about melatonin and heart failure turn a complicated observational study into something much scarier than what the data shows, and melatonin looks more like an innocent bystander than the cause. The real problems with melatonin are the high doses people take, the inaccurate labels on many products, and the fact that most people use it for a sleep problem it was never designed to fix.
Melatonin is not your body’s sleep switch, and for most people with insomnia the real issue is conditioned arousal. Sleep gets better when you line up your rhythm, your environment and your nervous system, with a consistent wake-up time, morning light, smart choices with caffeine, alcohol and meals, a real wind-down and a cool, dark and quiet bedroom. This framework isn’t easy, but it is simple and it’s well worth the effort.