Melatonin is the supplement that everybody feels good about. It is "natural." You can grab it at any gas station checkout. Parents give it to their kids, grandparents take it every night, and nobody blinks because the label says it comes from a pinecone or something. But a large preliminary study published in 2024 linked long-term melatonin use to a roughly 90% higher risk of developing heart failure over five years, and I have yet to see that headline anywhere near the vitamin aisle. So let's talk about what is actually in that little pink gummy, because the word "natural" is doing a lot of heavy lifting and it is time we looked behind it.

The Study Nobody at the Drug Store Is Talking About

The research, covered by ScienceDaily, looked at people with chronic insomnia who used melatonin long term. Over five years, that group showed a roughly 90% higher risk of developing heart failure compared to non-users. I want to be careful here because this is a preliminary, observational study. It does not prove that melatonin causes heart failure. The researchers themselves said the findings do not establish causation. What they do is raise serious questions about the assumption that long-term melatonin supplementation is automatically harmless because it is "natural."

But here is where I want to press pause. The reflex in our culture is to dismiss a study like this as "more research is needed" and go right on popping gummies. We did that with seed oils for decades. We did it with artificial sweeteners. At some point, "preliminary" findings deserve a real look instead of a shrug, especially when we are talking about something millions of people take every single night, including children.

If this were a study linking, say, red meat or eggs to anything, it would be front-page news by Tuesday. File that observation wherever you like.

What Is Actually in a Melatonin Supplement

Here is the part that genuinely bothers me. Melatonin is classified in the United States as a dietary supplement, which means it lives in a regulatory no-man's-land. The FDA does not review dietary supplements for safety or effectiveness before they hit the market, the way it reviews drugs. Manufacturers are largely responsible for ensuring their own products are safe, and the FDA only steps in after the fact if problems are reported.

What that means in practice is that the melatonin dose on the label may have little connection to what is actually in the pill. A 2017 study published in the Journal of Sleep Research tested 31 melatonin supplements and found that actual melatonin content ranged from 83% less than the label claimed to 478% more. Nearly 71% of the products were off by more than 10% from their stated dose, and 26% also contained serotonin, an active compound, that was not disclosed on the label at all. Not a trace amount. Actual serotonin.

So when someone says they are taking 1 mg of melatonin to be conservative, they may be taking a fraction of that or nearly 5 mg. And they have no way of knowing.

Beyond the melatonin itself, most commercial supplements, especially the gummies and chewables, also contain:

  • Added sugars or sugar alcohols (sorbitol, xylitol, maltitol) to make them palatable
  • Artificial flavors and colors, including synthetic dyes that are already restricted in other countries
  • Fillers and binders like magnesium stearate, silicon dioxide, and maltodextrin
  • Corn-derived ingredients, often from GMO corn with no disclosure required

The gummy format is particularly popular for children's melatonin products, which means kids are getting all of the above regularly. That is not a "natural" sleep aid. That is candy with a hormone in it, and we are giving it to five-year-olds.

The Dose Problem Is Bigger Than You Think

Your pineal gland produces melatonin too, obviously. That is the whole point. It is a hormone your brain makes in response to darkness, and it is part of the signaling chain that tells your body it is time to sleep. The amount your pineal gland secretes at night is quite small, generally in the range of 0.1 to 0.3 mg according to sleep researchers at MIT.

Most over-the-counter melatonin supplements start at 1 mg and commonly go up to 5 or 10 mg. The popular gummies are often 2.5 to 5 mg per piece, and because they taste like candy, people eat two. That is a dose somewhere between 10 and 50 times what your brain would naturally produce. And we have been treating this as a harmless thing to do every night, long term, without a second thought.

MIT's Dr. Richard Wurtman, one of the researchers who originally studied melatonin's sleep effects, has argued for years that the physiologically appropriate dose for sleep is around 0.3 mg, and that high doses may actually be counterproductive by flooding receptors and blunting sensitivity over time. His work from 2001 is still worth reading. It did not stop the supplement industry from launching 10 mg products, because there was no one to stop them.

The Regulatory Gap Nobody Wants to Close

Here is the follow-the-money part. The U.S. dietary supplement industry generates over $50 billion a year. Melatonin alone is a multi-billion-dollar market. The 1994 Dietary Supplement Health and Education Act, known as DSHEA, is the law that established the current framework where supplements are presumed safe until proven otherwise, and the burden of proof falls on the FDA to show harm, not on the manufacturer to show safety before selling.

The law has not been meaningfully updated since 1994. The industry lobbied hard for it then, and it has lobbied hard to keep it ever since. Meanwhile, in the European Union, melatonin above 0.5 mg is classified as a drug requiring a prescription. The UK is similar. Canada restricts dosing more tightly than we do. Other countries look at this same compound and say: this is a hormone, it needs oversight.

We look at it and put it in fruit-punch gummies for toddlers.

I am not saying melatonin is poison. I am saying the system that allows unlimited doses of a hormone to be sold as a "natural supplement" with minimal labeling accuracy requirements, no mandatory pre-market safety testing, and no long-term follow-up studies, is a system that serves the industry, not you.

What Your Body Was Actually Designed to Do

Your body was designed to make melatonin. It was designed to make it on its own, in the right amount, at the right time, in response to real signals like darkness and temperature drop. The fact that so many of us cannot do that anymore is the actual problem worth solving, and no supplement gets you there.

Light exposure is the main driver. Specifically, blue-wavelength light at night, the kind pouring off your phone and your TV and your overhead LED lights, suppresses melatonin production. A 2022 review in the International Journal of Molecular Sciences confirmed that artificial light at night disrupts circadian melatonin rhythms. If you are lying in bed doom-scrolling until midnight, your pineal gland is getting the same signal it gets at noon. It is not going to make melatonin. That is not a supplement deficiency. That is a behavior problem.

Food also plays a role. Tryptophan is an amino acid precursor to serotonin, which the body then converts to melatonin. Getting enough tryptophan from real food is one of the foundational steps. Eggs are a genuinely good source here. Two whole eggs contain roughly 170 to 200 mg of tryptophan, and they also supply B vitamins, particularly B6, which is a cofactor in that serotonin-to-melatonin conversion. A 2016 study in Nutrients identified tryptophan from protein sources as relevant to supporting melatonin synthesis. Including eggs at dinner is a small, real-food habit that works with your body's design, not around it.

Magnesium matters too. It is involved in regulating GABA, the calming neurotransmitter that helps your brain quiet down at night. A lot of people eating a standard American diet are low in magnesium because it has been stripped from processed food and depleted from soil. Leafy greens, pumpkin seeds, and quality dark chocolate are real-food sources.

None of this is as convenient as a gummy. I know. But you are not supposed to outsource a hormonal function to an unregulated supplement every night indefinitely. That was never the plan.

What I Actually Think You Should Do

If you are taking melatonin occasionally to reset after travel or shift work, the evidence for short-term use is reasonably solid and the risk picture looks different than long-term nightly use. But if melatonin has become your nightly non-negotiable and you have been doing that for months or years, this new preliminary data is worth taking seriously. Talk to your doctor, specifically about whether you should be using it long term and whether anyone has looked at your heart health in that context.

And if you have never looked at the actual ingredient panel on your melatonin product, today is a good day to start. Turn the bottle over. Read the "other ingredients" section. Count the additives. Look at the dose and remember that your brain's natural output is around 0.3 mg, then look at how many milligrams are in your tablet.

The body is a gift we were given to steward. The sleep it needs is not a problem for the supplement industry to solve with a 10 mg gummy and a fruit punch flavor. The solution is usually upstream: address the light, address the stress, eat real food, and give your body the basic conditions it was designed to work in.

That is not a headline anyone can sell you. Which is exactly why you are not hearing it.

This article is for general informational purposes only and is not medical advice. Always consult a qualified healthcare professional before making changes to your diet or health routine.

Key Takeaways

  • A large preliminary study linked long-term melatonin use to a roughly 90% higher risk of heart failure over five years, though it does not prove causation. The findings warrant serious attention.
  • Melatonin is classified as a dietary supplement in the U.S., meaning it is not reviewed for safety or effectiveness before sale. A 2017 study found that 70% of tested products contained significantly more or less melatonin than the label claimed.
  • Most commercial melatonin products, especially gummies, also contain added sugars, artificial flavors, synthetic dyes, fillers, and sometimes undisclosed active compounds.
  • The physiologically appropriate dose for sleep may be around 0.3 mg, far below the 1 to 10 mg found in most supplements, according to MIT research.
  • The EU, UK, and Canada regulate melatonin more strictly than the U.S. The American supplement industry's light regulatory burden is a product of the 1994 DSHEA law, which has not been meaningfully updated.
  • Real-food habits, managing light exposure at night, and adequate dietary tryptophan and magnesium (eggs are a solid whole-food source of tryptophan and B6) support your body's own melatonin production.

Sources

This article is for general informational purposes only and is not medical advice. Always consult a qualified healthcare professional before making changes to your diet or health routine.