A new look at a common sleep remedy

Millions of Americans reach for melatonin every night to fight sleeplessness, but new research suggests the popular supplement might come with unexpected consequences.

A preliminary study set to be presented at the American Heart Association’s Scientific Sessions this November found that consistent melatonin use was linked to a significantly higher risk of heart failure, hospitalization, and even death in adults diagnosed with chronic insomnia.

Researchers tracked more than 100,000 adults with insomnia and discovered that those who regularly took melatonin were 90 percent more likely to develop heart failure within five years than those who didn’t. They were also three and a half times more likely to be hospitalized for the condition.

Although the study did not prove melatonin directly causes heart problems, its findings have raised serious concerns about a supplement long considered harmless. Experts caution that more research is needed before drawing firm conclusions, but the results point to a growing need for awareness about what’s really in those little sleep gummies and pills.

How melatonin works in the body

Melatonin is a hormone produced naturally by the pineal gland, a small structure in the brain that helps regulate sleep and wake cycles. As daylight fades, melatonin levels rise, signaling to the body that it’s time to slow down. This process lowers body temperature, eases alertness, and prepares the body for rest.

For people struggling with insomnia, melatonin supplements are often seen as an easy fix. The hormone stays active in the body for about four to five hours and may provide short-term relief from sleeplessness. But medical experts have long debated whether it truly helps chronic insomnia—and whether it’s as safe as most people believe.

In the United States, melatonin is classified as a dietary supplement, not a prescription or over-the-counter medication. That means it’s not regulated by the Food and Drug Administration (FDA) in the same way as drugs, leaving product quality and dosage largely up to manufacturers. In other countries, melatonin is available only with a doctor’s prescription, reflecting a more cautious approach to its use.

Rising popularity, rising questions

The use of melatonin among U.S. adults has climbed dramatically in recent decades. According to data from the National Institutes of Health, the percentage of adults using melatonin rose from 0.4 percent in 1999–2000 to 2.1 percent in 2017–2018—a fivefold increase.

With that growth has come concern. While melatonin is marketed as a natural, gentle sleep aid, scientists are beginning to explore its potential impact on cardiovascular health. Previous studies have shown that poor sleep can raise the risk of high blood pressure, heart disease, and stroke, and researchers now wonder whether long-term melatonin use could be part of the problem rather than the solution.

Why regulation remains a challenge

Melatonin’s classification as a supplement makes it difficult to monitor for purity, strength, and safety. Studies have found that actual melatonin levels in supplements can vary significantly from what labels claim, and some products even contain trace amounts of other substances that could affect sleep or interact with medications.

That lack of regulation means consumers are often left guessing about what they’re really taking—and how much. Health professionals are calling for stronger oversight to ensure consistent quality and better inform the public about potential risks.

Healthier paths to better sleep

For those struggling with insomnia, experts still recommend cognitive behavioral therapy (CBT) as a first-line treatment. The therapy helps retrain the brain’s sleep patterns and addresses behaviors that interfere with rest.

Lifestyle changes can also make a difference. Turning off bright screens before bed, reading, meditating, and maintaining a consistent sleep schedule are proven methods to help the body produce melatonin naturally. Avoiding caffeine and heavy meals late at night can also support a more restful routine.

While melatonin may offer temporary relief for occasional sleeplessness, the new findings suggest that long-term use could carry unexpected risks. As research continues, many doctors urge patients to think twice before relying on supplements—and to seek safer, evidence-based ways to get a good night’s sleep.