Melatonin Does Not Cause Heart Disease
No, melatonin does not cause heart disease—in fact, the available evidence demonstrates cardiovascular safety and potential protective benefits. Major cardiovascular societies including the American Heart Association, American College of Cardiology, and Heart Failure Society of America do not list melatonin as a contraindication or harmful agent in patients with cardiac disease, and specifically identify harmful medications in heart failure, yet melatonin is not included in these warnings 1.
Evidence Supporting Cardiovascular Safety
The strongest clinical evidence comes from a prospective trial of 500 cardiac surgery patients receiving prophylactic melatonin, which showed reduced postoperative delirium (8.4% vs 20.8%, p=0.001) without any reported cardiac complications 1. This demonstrates that melatonin is safe even in the highest-risk cardiac population undergoing major surgery.
The Society for Perioperative Assessment and Quality Improvement recommends continuing melatonin through the perioperative period in cardiac surgery patients, demonstrating confidence in its cardiovascular safety 1.
Potential Cardiovascular Benefits
Research evidence suggests melatonin may actually protect against cardiovascular disease:
- Patients with coronary heart disease, heart failure, and hypertension typically exhibit lower nighttime melatonin levels, and this deficiency increases the likelihood of adverse cardiac events 2
- Studies demonstrate melatonin protects the heart against ischemia-reperfusion injury and may prevent cardiac muscle hypertrophy 3
- Melatonin has been shown to reduce blood pressure in both normotensive and hypertensive subjects, with even 1 mg doses reducing blood pressure and catecholamine levels within 90 minutes 4
- Melatonin suppresses cholesterol formation by 38% and reduces LDL accumulation by 42%, which could translate to a 20-30% decrease in coronary heart disease risk 4
Safety Profile and Precautions
The American Academy of Sleep Medicine reports no serious adverse reactions have been documented in relation to melatonin use across age groups, with the most frequently reported adverse events being headache (0.74%) and dizziness (0.74%) 1.
Important precautions to observe:
- Use caution in patients taking warfarin due to potential interactions—monitor INR more frequently when initiating or discontinuing melatonin 1
- Exercise caution in patients with epilepsy based on case reports 1
- Patients with impaired glucose tolerance should be aware that melatonin has been associated with impaired glucose tolerance in healthy individuals after acute administration 1
Dosing Recommendations
The American Academy of Sleep Medicine recommends starting with 3 mg of immediate-release melatonin, with dose titration in 3 mg increments only if needed, up to a maximum of 15 mg, as higher doses can cause receptor desensitization and more frequent adverse effects 1.
Common Pitfall to Avoid
The major caveat is that melatonin is regulated as a dietary supplement in the U.S., raising concerns about purity and reliability of stated doses 1. Choose United States Pharmacopeial Convention Verified formulations to minimize the risk of contaminants and ensure accurate dosing 1.