Hexarelin: A Synthetic Peptide That May Directly Protect the Heart Through a Unique Receptor

Hexarelin protects the heart not just through growth hormone release but via a dedicated cardiac receptor (CD36), making it a more stable and potent alternative to natural ghrelin.

Mao, Yuanjie et al.·Journal of geriatric cardiology : JGC·2014·low-moderateReview
RPEP-02438Reviewlow-moderate2014RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Review
Evidence
low-moderate
Sample
Not applicable (review of preclinical and mechanistic studies)
Participants
Not applicable (review of preclinical and mechanistic studies)

What This Study Found

Hexarelin, a synthetic growth hormone-releasing peptide, has direct cardiovascular effects beyond growth hormone release. It activates both the ghrelin receptor (GHSR) in the brain and a specific cardiac receptor called CD36, which mediates its cardioprotective effects. Compared to the natural hormone ghrelin, hexarelin is more chemically stable and functionally more potent.

The review summarizes evidence that hexarelin can protect the heart through direct actions on cardiac and vascular tissue, independent of its growth hormone-stimulating properties.

Key Numbers

2 receptors: GHSR (brain) and CD36 (cardiac) · More stable than ghrelin · More potent than ghrelin · Direct cardiac and vascular actions

How They Did This

Concise narrative review summarizing preclinical and mechanistic evidence for hexarelin's cardiovascular actions, including receptor binding studies, cardiac protection experiments, and comparisons with natural ghrelin.

Why This Research Matters

Growth hormone-releasing peptides have been studied primarily for their hormonal effects, but hexarelin's direct cardiac actions through the CD36 receptor represent a distinct therapeutic mechanism. If these cardioprotective effects can be harnessed clinically, hexarelin could serve as a targeted cardiac peptide therapy, particularly for conditions where growth hormone effects are unwanted.

The Bigger Picture

The discovery that growth hormone secretagogue peptides have direct cardiovascular effects through non-GHSR receptors expanded the field beyond endocrinology. Hexarelin and related peptides are now being studied as cardiac therapeutics, and the CD36 receptor pathway represents a novel pharmacological target for heart protection that is distinct from conventional cardiovascular drug mechanisms.

What This Study Doesn't Tell Us

As a brief narrative review, it does not comprehensively evaluate all available evidence or assess study quality. Most evidence is preclinical. Clinical cardiovascular studies of hexarelin are limited. The review is from 2014 and newer evidence may have emerged.

Questions This Raises

  • ?Can hexarelin analogs be designed that selectively activate CD36 without triggering growth hormone release?
  • ?Would hexarelin be beneficial in human heart failure or after myocardial infarction?
  • ?How does hexarelin's cardioprotection compare to established cardiovascular drugs in preclinical head-to-head studies?

Trust & Context

Key Stat:
Dual receptor mechanism Hexarelin acts through both GHSR (hormonal) and CD36 (cardiac) receptors, providing direct cardioprotection
Evidence Grade:
This is a narrative review of mostly preclinical evidence. While it identifies an interesting mechanism (CD36-mediated cardioprotection), human cardiovascular data for hexarelin remains limited.
Study Age:
Published in 2014, this review provides foundational context for hexarelin's cardiovascular pharmacology. The CD36 receptor and growth hormone secretagogue peptide field has continued to evolve since publication.
Original Title:
The cardiovascular action of hexarelin.
Published In:
Journal of geriatric cardiology : JGC, 11(3), 253-8 (2014)
Database ID:
RPEP-02438

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

Summarizes existing research on a topic.

What do these levels mean? →

Frequently Asked Questions

What is hexarelin?

Hexarelin is a synthetic peptide that mimics ghrelin, the body's natural hunger and growth hormone-releasing hormone. It's six amino acids long, more chemically stable than ghrelin, and binds to both the ghrelin receptor in the brain and a specific receptor (CD36) on heart cells. This dual action gives it both hormonal and direct cardiovascular effects.

How does hexarelin protect the heart?

Hexarelin binds to CD36 receptors on heart cells, triggering protective signaling pathways independent of growth hormone release. This direct cardiac action may protect against ischemia (reduced blood flow), heart failure, and other cardiovascular conditions, though most evidence comes from animal studies.

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Cite This Study

RPEP-02438·https://rethinkpeptides.com/research/RPEP-02438

APA

Mao, Yuanjie; Tokudome, Takeshi; Kishimoto, Ichiro. (2014). The cardiovascular action of hexarelin.. Journal of geriatric cardiology : JGC, 11(3), 253-8. https://doi.org/10.11909/j.issn.1671-5411.2014.03.007

MLA

Mao, Yuanjie, et al. "The cardiovascular action of hexarelin.." Journal of geriatric cardiology : JGC, 2014. https://doi.org/10.11909/j.issn.1671-5411.2014.03.007

RethinkPeptides

RethinkPeptides Research Database. "The cardiovascular action of hexarelin." RPEP-02438. Retrieved from https://rethinkpeptides.com/research/mao-2014-the-cardiovascular-action-of

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.