Hormones · Melatonin

Long-term melatonin therapy (≥1 year) is associated with increased risk of new onset heart failure, heart failure requiring hospitalization, and all-cause mortality in adult insomnia patients

A single unpublished conference abstract reported a statistically significant increased risk of new onset heart failure, heart failure requiring hospitalization, and all-cause mortality associated with long-term melatonin therapy (one year or longer) in adult patients with insomnia. This observation has not undergone peer review or independent validation and is considered hypothesis-generating.

2 min readUpdated Jul 8, 20260 RCTsView structured evidence →
Evidence Score34/100
Human RCT☆☆☆☆☆
Meta-analysis☆☆☆☆☆
Mechanism★★★★★
Safety★★★★
Confidencelow

This article is automatically generated from the structured evidence profile behind the claim above. Scores reflect the quality and quantity of available research, not clinical advice.

Long-term melatonin therapy (≥1 year) is associated with increased risk of new onset heart failure, heart failure requiring hospitalization, and all-cause mortality in adult insomnia patients The current body of evidence comprises 1 study. EvidenceHub rates the overall confidence at 34/100 (low).

The Claim

Long-term melatonin therapy (≥1 year) is associated with increased risk of new onset heart failure, heart failure requiring hospitalization, and all-cause mortality in adult insomnia patients

This conclusion is most relevant to: Adult patients suffering from insomnia.

What the Research Shows

The conclusion draws on 1 linked study. Highlights from the cited literature:

  • Melatonin supplementation, hyperprolactinemia, and incident heart failure: A proposed prolactin-mediated pathway for cardiovascular risk. (World journal of experimental medicine, 2026) —

How It Works

The proposed biological pathway:

  • Melatonin modulates hypothalamic dopaminergic neurons
  • Increased prolactin (PRL) release
  • Sustained hyperprolactinemia (hypothetical)
  • Cleavage of PRL to cardiotoxic 16-kDa fragment in patients with oxidative stress and cardiovascular risk factors
  • Increased risk of heart failure analogous to peripartum cardiomyopathy

Who Might Benefit

Evidence fit by population:

  • Adult patients suffering from insomnia

Limitations & Caveats

Important context when interpreting this evidence:

  • The primary association is from a single unpublished conference abstract that has not undergone peer review or independent validation
  • The proposed mechanistic pathway is speculative and unconfirmed, with unresolved critical knowledge gaps regarding sustained hyperprolactinemia with long-term melatonin use

Frequently Asked Questions

Is melatonin definitely linked to heart failure?

No. The reported association is from a single unpublished conference abstract that has not been peer-reviewed or independently validated. The paper itself describes the observation as hypothesis-generating and calls for further investigation.

How might melatonin increase heart failure risk?

The paper speculates that melatonin may increase prolactin release, and in patients with oxidative stress and cardiovascular risk factors, prolactin could be cleaved into a cardiotoxic 16-kDa fragment, similar to the mechanism in peripartum cardiomyopathy. This pathway is unconfirmed.

Should I stop taking melatonin based on this study?

No. This is a speculative hypothesis based on preliminary evidence. Melatonin is widely used and has historically been researched for cardioprotective effects. Consult your healthcare provider before making any changes.

What population was studied in this paper?

The abstract refers to adult patients suffering from insomnia who used long-term melatonin therapy (one year or longer). The specific demographics and sample size are not detailed in the abstract.

References

  1. 1.Savvidis C, Thomopoulos C, Ilias I. “Melatonin supplementation, hyperprolactinemia, and incident heart failure: A proposed prolactin-mediated pathway for cardiovascular risk..” World journal of experimental medicine, 2026. PMID: 42394777 DOI: 10.5493/wjem.v16.i2.120754
Disclaimer: This article is auto-generated from structured research data 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.