Melatonin Does Not Cause Heart Failure
Based on current evidence, melatonin does not cause heart failure and may actually provide cardiovascular protective benefits. The available research suggests melatonin supplementation could be beneficial rather than harmful for patients with existing heart disease.
Evidence Supporting Cardiovascular Safety
The most comprehensive safety data comes from major medical societies:
The Society for Perioperative Assessment and Quality Improvement recommends continuing melatonin through the perioperative period, confirming its safety profile even in high-risk surgical contexts 1
The American Academy of Sleep Medicine reports no serious adverse reactions documented across all age groups, with the most common side effects being only headache (0.74%) and dizziness (0.74%) - notably, cardiac events are not listed among adverse effects 1
Potential Cardiovascular Benefits
Research actually suggests the opposite relationship - melatonin may protect against heart disease:
Patients with heart failure, hypertension, and coronary disease typically have lower endogenous melatonin levels, and this deficiency increases the likelihood of adverse cardiac events 2
A 2025 meta-analysis found melatonin therapy in heart failure patients resulted in improved ejection fraction, better NYHA functional class (OR: 4.84), significantly elevated quality of life, reduced fatigue, and decreased NT-Pro BNP levels 3
Melatonin plays protective roles in major pathological processes associated with heart failure including ischemic injury, oxidative stress, apoptosis, and cardiac remodeling 4
Studies demonstrate cardioprotective activity through anti-oxidant mechanisms and prevention of cardiac muscle death in response to ischemia-reperfusion 5
Important Safety Considerations
While melatonin doesn't cause heart failure, certain precautions apply:
Use caution in patients taking warfarin due to potential drug interactions 1, 6
Patients with epilepsy should use melatonin cautiously based on case reports 1, 6
Start with 3 mg doses rather than higher amounts, as excessive dosing (10 mg+) can cause receptor desensitization and more frequent adverse effects like morning grogginess 7, 1
Choose United States Pharmacopeial Convention Verified formulations to ensure purity and accurate dosing, as melatonin is regulated as a dietary supplement 7, 1
Clinical Bottom Line
There is no evidence linking melatonin supplementation to the development or worsening of heart failure. The concern should be reversed - patients with cardiovascular disease may benefit from melatonin's cardioprotective properties, though more clinical trials are needed to establish definitive treatment protocols 4, 3.