The connection between melatonin and heart failure has gained renewed attention in 2025 as researchers continue exploring how this natural sleep hormone may affect cardiovascular health. New findings from several U.S. and international studies suggest that melatonin could play a potential protective role in patients with heart failure — but experts also emphasize that more evidence is needed before it becomes a standard part of treatment.
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Understanding Melatonin’s Role in the Body
Melatonin is a hormone produced by the pineal gland in the brain. It regulates the body’s sleep–wake cycle, helping signal when it’s time to rest. Its production typically rises in the evening and decreases in the morning, guided by light exposure.
Beyond its role in sleep, melatonin has powerful antioxidant and anti-inflammatory properties. Researchers have long studied these effects for their potential benefits in conditions such as neurodegeneration, diabetes, and cardiovascular disease. Now, the spotlight is on whether melatonin might improve outcomes in people with heart failure.
Heart Failure and Why It Matters
Heart failure occurs when the heart cannot pump enough blood to meet the body’s needs. It’s a major public health issue in the United States, affecting more than 6 million adults, according to the Centers for Disease Control and Prevention (CDC).
Common causes include coronary artery disease, high blood pressure, and previous heart attacks. Symptoms such as shortness of breath, fatigue, and swelling in the legs can severely limit quality of life.
Traditional treatment includes lifestyle changes, medications (like beta-blockers and ACE inhibitors), and, in some cases, surgical procedures or devices. Researchers continue to search for therapies that can protect the heart from further damage — and melatonin has emerged as a promising area of study.
Recent Findings Linking Melatonin and Heart Failure
Several studies published in 2024 and 2025 have explored how melatonin might support heart function or reduce the risk of heart failure-related complications.
- A 2024 study in the European Heart Journal found that patients with chronic heart failure often had significantly lower nighttime melatonin levels compared to healthy adults. Researchers concluded that melatonin deficiency could be linked to worsening cardiac function.
- A 2025 meta-analysis from the American College of Cardiology (ACC) reviewed more than 15 clinical trials involving melatonin use in cardiovascular conditions. The analysis suggested that melatonin supplementation improved heart rate variability and reduced markers of oxidative stress in some patients.
- Animal and cellular studies from U.S. universities, including the Mayo Clinic and Stanford Medicine, demonstrated that melatonin may reduce inflammation in heart tissue and limit damage to heart muscle cells caused by oxidative stress.
While these results are encouraging, cardiologists caution that large-scale clinical trials in humans are still limited.
How Melatonin May Protect the Heart
Researchers are investigating several possible mechanisms behind melatonin’s effects on heart failure:
- Antioxidant activity: Melatonin helps neutralize free radicals, which can damage heart cells and blood vessels.
- Anti-inflammatory effects: It may reduce inflammation that contributes to the progression of heart failure.
- Mitochondrial protection: Melatonin supports the function of mitochondria — the “energy factories” in heart cells — which are often impaired in heart failure.
- Improved blood pressure regulation: Some studies show that melatonin may modestly lower nighttime blood pressure, helping reduce cardiac strain.
These combined effects suggest that melatonin could potentially protect the heart and slow disease progression, especially when used alongside standard heart failure therapies.
What Doctors Are Saying in 2025
Cardiologists in the U.S. are cautiously optimistic about melatonin’s potential benefits but stress that it should not replace medical treatment.
Dr. Sarah Holden, a cardiologist at the Cleveland Clinic, recently stated that “melatonin is showing intriguing results in early research, particularly for its antioxidant effects on the heart. However, patients should always consult their physicians before adding supplements, as dosage, timing, and drug interactions can vary.”
Experts also emphasize that over-the-counter melatonin products are not regulated as strictly as prescription medications, meaning purity and potency may differ between brands.
Melatonin Supplementation and Sleep in Heart Failure
Sleep problems are common in people with heart failure. Conditions like sleep apnea and insomnia can worsen heart strain and reduce recovery. Because melatonin regulates sleep patterns, researchers are studying whether it can improve sleep quality and, in turn, benefit heart health indirectly.
In a 2025 clinical trial from the University of Michigan, patients with mild heart failure who took low-dose melatonin (2 mg nightly) for three months reported improved sleep efficiency and lower nighttime heart rates. However, researchers noted no significant changes in ejection fraction — a measure of how well the heart pumps blood.
These findings suggest that while melatonin might not directly strengthen heart function, it could enhance overall well-being and reduce nighttime stress on the heart.
Dosage and Safety Considerations
Most studies examining melatonin and heart failure have used daily doses between 1 mg and 10 mg, typically taken at bedtime. However, researchers stress that dosage should be tailored to the individual, as higher amounts may cause side effects such as daytime drowsiness, vivid dreams, or hormonal interference.
Potential safety considerations include:
- Medication interactions: Melatonin may interact with blood thinners, diabetes medications, and blood pressure drugs.
- Underlying conditions: People with autoimmune disorders or hormone-sensitive cancers should seek medical advice before using it.
- Timing: Because melatonin affects circadian rhythm, it’s best taken under a doctor’s supervision, especially for those with heart-related sleep issues.
Currently, the U.S. Food and Drug Administration (FDA) classifies melatonin as a dietary supplement, not a drug, meaning it’s widely available but not subject to prescription-level regulation.
What Future Research Is Focusing On
Scientists are continuing to explore how melatonin might be integrated into broader heart failure care. Several clinical trials are underway in 2025 to evaluate its long-term cardiovascular impact.
Key areas of focus include:
- Whether melatonin supplementation can reduce hospitalizations for heart failure.
- How it affects heart rate variability and blood vessel function.
- Its potential role in protecting the heart after cardiac surgery or heart attacks.
Results from these studies are expected in 2026 and 2027, which may provide stronger guidance for doctors considering melatonin as a complementary therapy.
A Balanced Perspective
While melatonin offers promise, experts remind patients that lifestyle and medical care remain the foundation of heart failure management. Maintaining a heart-healthy diet, staying active under medical supervision, limiting salt intake, and adhering to prescribed medications remain essential steps.
Melatonin may one day become an additional tool in improving quality of life for heart failure patients, especially those struggling with sleep or oxidative stress. But for now, it remains a supportive supplement, not a cure or replacement for conventional treatment.
As research continues, do you think melatonin could play a bigger role in heart health care? Share your thoughts in the comments and stay informed about the latest medical updates!