For years, melatonin has been seen as a quiet hero of modern sleep. Sold in cheerful bottles and sweetened into gummies, it promised to restore the natural rhythm our screen-lit lives had disturbed. Millions have turned to it nightly, trusting in its reputation as a harmless, natural way to drift into rest. But a new study from the American Heart Association’s 2025 Scientific Sessions has shaken that faith, suggesting that long-term melatonin use may be linked to a startling 90 percent higher risk of heart failure.

The finding, splashed across headlines, seems almost paradoxical. How could a hormone our bodies naturally produce—the very signal of darkness that guides us toward sleep be tied to one of the most serious cardiovascular outcomes? And more importantly, what does this say about the delicate balance between biology, medicine, and our spiritual understanding of rest? This is a story not only about science, but about how we treat our exhaustion.

The Study That Sparked a Sleepless Conversation

The research that ignited this discussion comes from an observational analysis of more than 130,000 adults with chronic insomnia. Over a five-year period, scientists compared those who took melatonin for at least one year with those who did not. What they found was unnerving: people who regularly used melatonin had a 90 percent higher risk of developing heart failure, were more than three times as likely to be hospitalized for it, and nearly twice as likely to die from any cause.

Dr. Ekenedilichukwu Nnadi, the study’s lead author and chief resident in internal medicine at SUNY Downstate/Kings County Primary Care in Brooklyn, noted that the findings challenge the long-standing belief that melatonin is benign. “Melatonin supplements may not be as harmless as commonly assumed,” he explained. “If our study is confirmed, this could affect how doctors counsel patients about sleep aids.”

Yet, as with all observational studies, causation remains uncertain. The researchers did not determine whether melatonin itself caused heart failure or if it was simply more common among people already predisposed to cardiovascular disease. Still, the magnitude of the association nearly doubling the risk was enough to raise eyebrows and spark a public health debate.

Melatonin: Nature’s Signal of Night

To understand the heart of the matter, it helps to revisit what melatonin actually is. Melatonin is a hormone produced by the pineal gland, a small, pinecone-shaped structure tucked deep within the brain. Often called the “seat of the soul” by mystics and philosophers, the pineal gland has fascinated both spiritual seekers and scientists for centuries.

When light fades and darkness settles in, the pineal gland begins releasing melatonin, signaling to the body that it’s time to rest. This process is part of our circadian rhythm the internal clock that governs sleep, hormone production, and even cellular repair. In this natural dance, melatonin does not force sleep; it whispers a suggestion to the body, aligning us with the rhythms of night and day.

The issue arises when this rhythm is disrupted. Modern life, with its glowing screens and irregular schedules, often suppresses melatonin production, leading to insomnia and fatigue. In response, many people reach for supplements, hoping to restore what technology and stress have taken away.

But the melatonin found in over-the-counter pills is not the same as the subtle ebb and flow orchestrated by the pineal gland. Dosages sold in the United States often range from 3 to 10 milligrams, which is 100 to 1,000 times higher than what the body naturally produces. That massive difference may have physiological consequences science is only beginning to understand.

When “Natural” Isn’t Synonymous with “Safe”

Part of melatonin’s popularity comes from its natural label. In an age wary of pharmaceuticals, it seems gentle and trustworthy, even child-friendly. But the label “natural” can be misleading. The melatonin in supplements may be synthetically manufactured or extracted from animal glands, and the U.S. Food and Drug Administration does not regulate it as strictly as prescription drugs. This means dosage inconsistencies, impurities, and hidden additives are not uncommon.

Dr. Wendy Troxel, a sleep therapist and senior scientist at the RAND Corporation, called the recent findings “an important wake-up call.” She warned that the huge variability in potency among products means people may be taking much higher doses than they realize. “The availability of 5mg and 10mg doses defies logic,” she said, noting that the body naturally produces only fractions of a milligram per day.

In essence, the supplement industry has turned a delicate biological cue into a pharmacological hammer. When we take melatonin at such high doses, especially over long periods, we might be overriding intricate hormonal networks that regulate not only sleep but cardiovascular health, metabolism, and cellular aging.

What the Heart Has to Do With Sleep

At first glance, the connection between melatonin and heart failure seems unlikely. Yet the body is an interwoven system, and sleep is one of its most vital regulatory functions. Chronic insomnia itself has long been linked with increased risks of heart disease, high blood pressure, and stroke. When sleep falters, so does the body’s ability to repair and regulate.

Dr. Joyce Oen-Hsiao of Yale School of Medicine emphasized that poor sleep can directly harm the heart, while Dr. Karan Rajan, an NHS surgeon who discussed the study online, added a crucial nuance: people with early, undiagnosed heart failure often experience difficulty sleeping. These individuals might reach for melatonin as a solution, which makes the supplement more common among those already at risk.

In this view, melatonin may not be the villain but a marker a signal that someone’s body is already under stress. As Rajan explained, “Melatonin might not be the cause, but simply a symptom of something that’s already happening.”

Still, it’s possible that high-dose, long-term melatonin use interferes with the body’s natural cardiovascular regulation. The hormone has antioxidant properties and interacts with receptors throughout the body, including in the heart. Too much could throw that balance off, much like too much of any hormone can tip the body out of harmony. The line between medicine and poison, as the old saying goes, is the dose.

The Physiology of a Disrupted Rhythm

To understand how melatonin might affect the heart, we have to consider the delicate architecture of circadian biology. Every cell in the body follows its own clock, and these clocks are synchronized by the brain’s master timekeeper in the hypothalamus. When melatonin is taken externally, especially at irregular hours, it can desynchronize these cellular rhythms.

In the short term, this might not matter much. But over years, constant misalignment between the heart’s cellular clocks and the brain’s timing signals could contribute to inflammation, oxidative stress, and even heart muscle dysfunction. Animal studies have shown that chronic circadian disruption increases vulnerability to cardiovascular disease.

Interestingly, melatonin’s dual nature complicates the picture. Some studies suggest it protects the heart by reducing oxidative stress, while others hint that excessive doses or mistimed use may have the opposite effect. The truth is likely a complex interplay between dose, timing, and individual physiology.

This underscores a deeper truth about the human body: our biology is not binary. It’s rhythmic, contextual, and deeply responsive to balance.

The Spiritual Dimension of Sleep

Beyond the biology, there is something profoundly spiritual about sleep. In nearly every mystical tradition, sleep represents a return to source a nightly surrender to the unknown. The dream world has long been viewed as a realm of healing and reflection, where the subconscious communicates through symbol and story.

When we lose sleep, or attempt to mechanize it through artificial means, we lose touch with this dimension of being. Insomnia is not only a physiological condition but often a symptom of existential imbalance. The mind races because the soul has no rest.

In this light, the widespread reliance on melatonin is a mirror of collective burnout. We live in a culture that prizes productivity over peace, light over darkness, stimulation over stillness. Instead of addressing the root our disconnection from natural rhythms we medicate it with synthetic nightfall.

Perhaps the lesson here is not simply that melatonin might strain the heart, but that our entire relationship with rest has become distorted. We are trying to engineer sleep instead of surrendering to it.

The Science of Surrender

Good sleep hygiene, as unromantic as it sounds, is a sacred practice. It’s about aligning oneself with the cycles of nature: dimming lights as the sun sets, avoiding screens that emit blue light, and creating a bedroom that feels like a sanctuary rather than an extension of the office.

Dr. Marie-Pierre St-Onge, director of the Center of Excellence for Sleep & Circadian Research at Columbia University, advises that melatonin should never be taken chronically without medical supervision. She recommends behavioral approaches like cognitive behavioral therapy for insomnia, which teaches the body and mind to trust the rhythm of rest again.

Small changes consistent bedtimes, light exposure during the morning, relaxation rituals before bed have measurable effects on melatonin levels and cardiovascular health. Science increasingly shows that sleep is not a passive state but an active process of repair and renewal. The body’s immune system, hormones, and heart function all recalibrate in the quiet hours. In essence, sleep is both science and sacrament.

Where Science Meets Spirituality

If we step back from the clinical data and look through a wider lens, the melatonin story becomes part of a much larger pattern. It’s a cautionary tale about the modern tendency to isolate and commodify the natural processes of life. We have taken the body’s own night-signal and turned it into a product, a shortcut, a chemical comfort.

But melatonin was never meant to be a switch we flip on demand. It was meant to be a signal of harmony, a molecular whisper from the universe that it’s time to turn inward. When used judiciously perhaps to help with jet lag or short-term rhythm adjustment it can be helpful. But when used as a nightly crutch, it risks masking deeper imbalances in body, mind, and spirit.

The heart, both literal and metaphorical, thrives on rhythm. Every beat is a pulse of cosmic timing, a reminder that we are synchronized with something greater than ourselves. When our rhythms are thrown off whether by stress, artificial light, or overreliance on supplements the heart bears the cost. True rest, like true healing, is not something we can buy. It is something we must relearn.

Moving Toward Balance

The message from the American Heart Association’s study is not to panic or throw away your melatonin bottle, but to pause and reevaluate. Science rarely offers absolute answers; instead, it gives us patterns to interpret. The pattern here suggests caution with long-term, high-dose use and a renewed emphasis on addressing the root causes of sleeplessness.

If insomnia persists, it may be pointing toward deeper issues unresolved stress, emotional strain, or even cardiovascular risk factors themselves. Consulting a physician to uncover those underlying dynamics is far wiser than relying on over-the-counter hormones indefinitely.

At the same time, this research is a call to reconnect with the natural flow of light and dark. The body already knows how to sleep; we simply need to give it permission.

A Final Reflection

The pineal gland’s secretion of melatonin has always carried a touch of mystery. In esoteric traditions, it was seen as the bridge between the physical and spiritual worlds, the gland of insight and awakening. It is poetic, then, that its synthetic counterpart might now remind us of the cost of artificial living.

The heart and the pineal gland are both rhythmic organs, each pulsing to their own celestial beat. When they fall out of sync, disease can emerge not only as a medical condition but as a metaphor for our age: disconnected, overstimulated, and longing for rest.

Perhaps this new research is not merely a warning about a supplement, but a message about how we live. Sleep is not a problem to solve; it is a relationship to restore. And like all relationships, it begins with listening to our bodies, our hearts, and the quiet intelligence of the night.

Returning to the Rhythm of the Night

The growing concern over melatonin’s link to heart failure is not a call for fear but for awareness. Every era of science begins by seeing something familiar in a new light, and this study invites us to rethink our relationship with sleep and supplementation.

Our hearts and our hormones are not isolated mechanisms. They are living expressions of rhythm, responding to sunlight, darkness, emotion, and the subtle geometry of time. When we try to control these natural processes through external fixes whether it’s a pill, a screen, or a schedule that ignores sunrise and sunset we lose the intelligence that evolution encoded into every cell.

Melatonin was never meant to be a nightly ritual of dependency; it was meant to be a guidepost, reminding us when to surrender. Perhaps this new data is the universe’s way of reminding us to listen to the pulse of our hearts, to the whisper of nightfall, and to the ancient rhythm of life that still moves quietly within us.

To heal the modern epidemic of exhaustion, we don’t just need better sleep. We need reconciliation with the cycles we have forgotten. Sleep, like breath, is sacred. When we honor it naturally, without forcing or numbing, the heart follows suit steady, open, and in tune with the vast rhythm of the cosmos.

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