HormonesMelatonin

Melatonin supplementation may be associated with ventricular arrhythmia in some individuals

A 63-year-old man developed ventricular arrhythmia while taking 10 mg of exogenous melatonin daily, with complete resolution of symptoms and improvement in electrocardiographic findings after discontinuation. A systematic review identified similar arrhythmic events associated with melatonin supplementation, with symptom resolution or clinical improvement after stopping the supplement.

Last updated: Aug 8, 2026•0 RCTs•📖 Read as article →

Evidence Score

Evidence Score7/100
Human RCT☆☆☆☆☆
Meta-analysis☆☆☆☆☆
Mechanism★★★★★
Safety★★☆☆☆
Confidencelow

Study Evidence

Study 1. Atrioventricular Block Potentially Associated with Melatonin Supplementation: A Case Report and Systematic Review of Cardiac Rhythm Adverse Events.

observational

Sola E, Ramos E, Romero A, Monzón D · Pharmaceuticals (Basel, Switzerland) (2026)

Participants: N/A
Duration: N/A
Intervention: 10 mg exogenous melatonin daily
Outcome: Ventricular arrhythmia, cardiovascular symptoms, electrocardiographic findings
Effect Size: N/A
Population: 63-year-old man (case) and reports from systematic review

Result:

PubMed: 42515750DOI: 10.3390/ph19071069

Mechanism Graph

Melatonin receptor activation
↓
Sleep architecture changes
↓
Pharmacokinetic variability
↓
Genetic predisposition
↓
Cardiac rhythm and conduction disturbances

Limitations

  • ⚠Single case report with limited generalizability
  • ⚠Systematic review may include heterogeneous and low-quality reports

Frequently Asked Questions

What dose of melatonin was associated with the arrhythmia?▼

The patient was taking 10 mg of exogenous melatonin daily.

Did the patient recover after stopping melatonin?▼

Yes, the patient experienced complete resolution of symptoms and improvement in electrocardiographic findings after discontinuing melatonin.

Is melatonin generally safe for the heart?▼

Melatonin is generally regarded as safe with cardioprotective effects, but this report and systematic review suggest rare cardiac rhythm adverse events may occur.

What mechanisms might explain melatonin-related arrhythmias?▼

Possible mechanisms include melatonin receptor effects, sleep architecture changes, pharmacokinetic variability, and genetic predisposition.

Products

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References

  1. 1.Sola E, Ramos E, Romero A, Monzón D. "Atrioventricular Block Potentially Associated with Melatonin Supplementation: A Case Report and Systematic Review of Cardiac Rhythm Adverse Events.." Pharmaceuticals (Basel, Switzerland), 2026. PMID: 42515750 DOI: 10.3390/ph19071069
Disclaimer: This content is for educational purposes only and is not medical advice. Evidence scores reflect the quality and quantity of available research, not clinical recommendations. Always consult a healthcare professional before starting any supplement or intervention.