Melatonin Does Not Cause Heart Problems and May Actually Protect the Cardiovascular System
Based on current evidence from major medical societies, melatonin is safe for cardiovascular use and demonstrates cardioprotective properties rather than causing heart problems. The American Academy of Sleep Medicine reports no serious adverse reactions documented with melatonin use across age groups, and the Society for Perioperative Assessment and Quality Improvement recommends continuing melatonin through the perioperative period, confirming its cardiovascular safety 1.
Evidence Supporting Cardiovascular Safety
Melatonin appears to benefit rather than harm the cardiovascular system through multiple protective mechanisms:
Patients with cardiovascular disease (heart failure, hypertension, coronary heart disease) actually have lower melatonin levels at night, and this deficiency increases the likelihood of adverse cardiac events 2
Research demonstrates melatonin provides cardioprotection through anti-inflammatory, antioxidant, and anti-hypertensive effects 3, 4
Studies show melatonin reduces cardiac pathology and prevents death of cardiac muscle in response to ischemia-reperfusion injury 5
Melatonin may reduce blood pressure through direct hypothalamic effects, antioxidant activity, decreased catecholamine levels, and smooth muscle relaxation in the aorta wall 6
Documented Adverse Effects (None Cardiovascular)
The most common side effects of melatonin are minor and unrelated to cardiac function:
Headache (0.74%) and dizziness (0.74%) are the most frequently reported adverse events 1
Morning sleepiness and gastrointestinal upset occur more commonly at higher doses (>10mg) 7
No serious cardiovascular adverse reactions have been documented in clinical trials 1
Specific Cardiovascular Populations
Melatonin may be particularly beneficial in patients with cardiovascular risk factors:
Patients with coronary heart disease have low melatonin production rates, especially those at higher risk of cardiac infarction or sudden death 6
People with hypertension have lower melatonin levels than those with normal blood pressure, and melatonin administration (even 1mg doses) reduces blood pressure to normal range within 90 minutes 6
Individuals with high LDL-cholesterol have low melatonin levels; melatonin suppresses cholesterol formation by 38% and reduces LDL accumulation by 42% 6
Important Precautions (Not Cardiac-Related)
While melatonin is cardiovascularly safe, certain precautions apply:
Use caution in patients taking warfarin due to potential interactions 1, 8
Patients with epilepsy should use melatonin cautiously based on case reports 1, 8
Melatonin has been associated with impaired glucose tolerance in healthy individuals after acute administration 1, 8
Patients on photosensitizing medications should undergo periodic ophthalmological/dermatological monitoring 8
Optimal Dosing for Safety
Start with 3mg of immediate-release melatonin, as lower doses are safer and often more effective:
The American Academy of Sleep Medicine recommends starting at 3mg, with titration in 3mg increments only if needed, up to maximum 15mg 1, 7
Higher doses (10mg) cause receptor desensitization and more frequent adverse effects without additional cardiovascular benefit 7
Administer 1.5-2 hours before desired bedtime for optimal effect 7, 8
Choose United States Pharmacopeial Convention Verified formulations to minimize contaminant risk 1, 7
Clinical Bottom Line
There is no credible evidence that melatonin causes heart problems. In fact, the preponderance of evidence suggests melatonin has cardioprotective properties and may benefit patients with cardiovascular disease 2, 3, 4, 5. The cardiovascular system appears to be one of the safest organ systems with respect to melatonin use, with major medical societies confirming its safety profile 1.