Melatonin and Heart Rhythm
Melatonin is a hormone produced by the pineal gland that helps regulate sleep-wake cycles. It is sold as a dietary supplement in the United States and is not approved as a drug by the FDA. Some users report palpitations or changes in heart rate after taking melatonin. According to a 2023 review in the journal Nutrients, melatonin can modestly lower blood pressure and may slightly slow heart rate in healthy adults.
Clinical trials show mixed results on heart rhythm. A small study published in 2022 found that 3 mg of melatonin did not significantly change QT intervals in most participants. However, case reports link high doses to temporary bradycardia or skipped beats. People with existing arrhythmias should consult a cardiologist before use.
Melatonin and Cardiovascular Risk Factors
Melatonin has antioxidant and anti-inflammatory properties that may support blood vessel function. A 2024 meta-analysis in Journal of the American Heart Association noted that melatonin supplementation was associated with small reductions in systolic blood pressure.
Melatonin is not known to directly cause heart attacks or strokes in low doses. However, supplements are not strictly regulated, and product purity varies. The FDA has issued warnings about melatonin gummies containing inaccurate labels or undeclared ingredients. Consumers should look for third-party tested brands and avoid combining melatonin with blood thinners or blood pressure medications without medical advice.
Who Should Avoid Melatonin for Heart Safety
People with autoimmune conditions, depression, or bleeding disorders should be cautious. Melatonin can interact with immunosuppressants, anticoagulants, and diabetes drugs. The European Medicines Agency and the FDA have not approved melatonin for long-term heart protection, and high-dose use remains experimental.
Older adults and those with liver or kidney disease may process melatonin more slowly, increasing the risk of side effects. Typical doses range from 0.5 mg to 5 mg, and higher doses do not improve sleep but may raise the chance of dizziness or low blood pressure. For heart patients, a personalized plan from a doctor is essential before starting melatonin.