Interest in the link between melatonin and heart failure is growing quickly as new studies uncover how this naturally occurring hormone might protect the heart. Once known mainly as a sleep aid, melatonin is now at the center of cardiovascular research, with scientists examining its role in reducing inflammation, improving heart function, and supporting recovery in people with heart failure.
As of November 2025, researchers in the United States and Europe have published multiple studies exploring how melatonin’s antioxidant and anti-inflammatory properties may benefit heart patients. While findings are promising, experts emphasize that melatonin is not a cure — but it could become an important complementary tool in heart health management.
Understanding the Connection Between Melatonin and Heart Failure
Melatonin is produced by the pineal gland, a tiny organ deep within the brain. It helps regulate the body’s circadian rhythm — the natural cycle of sleep and wakefulness. Levels of melatonin typically rise at night and drop in the morning, signaling the body to rest.
However, researchers have discovered that melatonin’s effects go far beyond sleep. It also acts as a powerful antioxidant, protecting cells from oxidative stress — a process that can damage tissues, including the heart. Because oxidative stress and inflammation are key contributors to heart failure, scientists are investigating how melatonin may counteract those effects.
Heart failure occurs when the heart can’t pump blood effectively. This condition affects more than 6 million adults in the United States, according to the CDC, and leads to over 380,000 deaths each year. As treatments improve and patients live longer, attention has turned to complementary therapies that may slow disease progression and improve quality of life — melatonin among them.
Why Melatonin Matters in Heart Health
Melatonin’s influence on the cardiovascular system is complex. Research shows it interacts with heart tissue, blood vessels, and the nervous system in ways that may benefit patients with heart disease.
Key biological actions of melatonin that could support heart health include:
- Antioxidant defense: Melatonin helps neutralize free radicals that cause oxidative stress in cardiac cells.
- Anti-inflammatory activity: It reduces inflammatory cytokines — proteins that contribute to tissue damage in heart failure.
- Vascular support: Melatonin promotes better endothelial function, helping blood vessels relax and maintain healthy blood pressure.
- Mitochondrial protection: It supports energy production in heart muscle cells, which are highly dependent on efficient mitochondria.
- Circadian regulation: It stabilizes sleep cycles and heart rhythms, which can be disrupted in people with chronic heart failure.
These combined actions make melatonin a molecule of interest for both cardiologists and sleep medicine specialists.
Recent U.S. Studies on Melatonin and Heart Failure (2024–2025)
Research over the past two years has expanded rapidly, with several key studies shaping current understanding.
- Harvard Medical School (2024):
A team found that patients with advanced heart failure had significantly lower nighttime melatonin levels than healthy individuals. The researchers concluded that low melatonin production may correlate with worsening heart function and poor sleep quality. - Mayo Clinic Study (2025):
In an early clinical trial involving 120 patients, low-dose melatonin (3 mg nightly) improved sleep efficiency and reduced nighttime heart rate in patients with mild heart failure. The study also noted reduced levels of oxidative stress markers in participants’ blood samples. - European Heart Journal Review (2025):
A review of multiple animal and human studies found that melatonin supplementation reduced inflammation in cardiac tissue and improved survival rates in laboratory models of heart failure.
These findings have encouraged researchers to continue exploring melatonin’s use as an adjunct therapy — meaning it could complement, but not replace, standard heart medications.
Melatonin’s Impact on Sleep and Cardiac Recovery
Poor sleep is common among people with heart failure. Issues such as insomnia and sleep apnea can worsen heart symptoms and make recovery harder. Melatonin’s primary role in sleep regulation has made it an appealing option for improving rest and, indirectly, cardiovascular function.
When patients sleep better, their blood pressure, heart rate, and stress hormone levels stabilize. Studies suggest that even small improvements in sleep duration can lead to better heart performance and lower hospital readmission rates for heart failure patients.
Researchers also note that melatonin may help restore normal heart rhythm. The hormone interacts with receptors in the autonomic nervous system, which controls heart rate and blood vessel dilation. This could help prevent nighttime spikes in blood pressure and arrhythmias — common complications in advanced heart disease.
How Melatonin Works in the Heart
Scientists are still mapping the precise pathways through which melatonin affects heart tissue, but several mechanisms are already known:
| Mechanism | Potential Benefit for Heart Failure |
|---|---|
| Antioxidant protection | Reduces oxidative damage to heart muscle cells |
| Anti-inflammatory response | Limits tissue scarring and swelling in the heart |
| Endothelial support | Improves circulation and vessel flexibility |
| Calcium regulation | Helps control heartbeat rhythm and contractility |
| Mitochondrial energy balance | Increases energy efficiency of cardiac cells |
This combination of effects makes melatonin particularly valuable for aging patients, whose natural antioxidant defenses decline over time.
Dosage and Clinical Considerations
In most heart-related studies, melatonin doses range between 2 mg and 10 mg per day, usually taken 30–60 minutes before bedtime. However, experts emphasize that melatonin should not be self-prescribed at high doses, as its interaction with prescription drugs — especially beta-blockers, anticoagulants, and diabetes medications — can alter treatment outcomes.
Side effects are typically mild and may include:
- Daytime sleepiness
- Vivid dreams
- Headaches or dizziness
- Short-term hormonal changes in rare cases
Before starting melatonin, patients should consult a healthcare provider familiar with both cardiovascular and sleep medicine. Doctors can recommend appropriate dosages, monitor for drug interactions, and adjust treatment as needed.
Melatonin Deficiency in Heart Failure Patients
An emerging area of research focuses on melatonin deficiency as a possible factor in heart disease progression. Studies show that patients with chronic heart failure often have significantly lower nighttime melatonin levels than healthy individuals.
This may occur for several reasons:
- Disrupted circadian rhythms due to frequent hospitalizations and stress
- Use of beta-blockers, which can suppress natural melatonin production
- Poor sleep quality and exposure to artificial light at night
As a result, supplementing melatonin under medical supervision could help restore balance and protect against further deterioration.
Current Clinical Trials and What Comes Next
As of late 2025, several clinical trials in the U.S., Europe, and Asia are investigating melatonin’s role in heart failure treatment.
These trials aim to answer key questions:
- Can melatonin supplementation reduce hospital readmissions in heart failure patients?
- Does long-term melatonin use improve heart pumping capacity (ejection fraction)?
- How does melatonin affect quality of life, sleep, and stress hormone levels?
Preliminary data suggest potential benefits, especially for older adults and patients with nighttime hypertension or oxidative stress. The next few years will be crucial in determining whether melatonin can transition from a supplemental sleep aid to a recognized component of cardiovascular therapy.
Cautions and Safe Use
While melatonin appears safe for short-term use, experts caution that supplements vary widely in purity and dosage accuracy. The U.S. Food and Drug Administration (FDA) does not regulate melatonin as a prescription drug, meaning that over-the-counter versions may differ in potency.
To ensure safety:
- Choose verified brands with third-party testing.
- Avoid combining melatonin with alcohol or sedatives.
- Discuss any supplement use with your cardiologist or primary care provider.
For patients with heart failure, coordination between cardiology and sleep medicine specialists ensures melatonin use supports — rather than interferes with — standard care.
Lifestyle and Complementary Support for Heart Health
While melatonin may help reduce stress on the heart, it works best alongside lifestyle habits proven to strengthen cardiac health:
- Follow a heart-healthy diet: Emphasize vegetables, fruits, whole grains, lean protein, and omega-3 fats.
- Engage in regular physical activity: Moderate exercise, approved by your doctor, helps maintain blood flow and stamina.
- Manage stress: Deep breathing, meditation, and consistent sleep schedules enhance melatonin’s natural effects.
- Avoid late-night screen time: Artificial blue light suppresses melatonin production and disrupts sleep cycles.
Together, these strategies support healthy circadian rhythms and cardiovascular balance.
A Promising Future for Melatonin in Cardiology
Melatonin’s expanding role in cardiovascular research represents a major shift in how doctors view hormones and heart health. Once seen only as a sleep regulator, melatonin is now recognized as a multi-functional molecule with the potential to aid millions of Americans living with heart failure.
If ongoing trials confirm its protective effects, melatonin could one day join the list of evidence-based adjunct therapies that improve survival and quality of life for heart failure patients. For now, its use should remain guided by medical professionals — but the science points toward a hopeful future.
Do you think melatonin could become part of future heart failure treatments? Share your thoughts and stay tuned for new research updates in this exciting area of heart health!