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evidence · mechanism · dose
Experimental/GH SecretagogueResearch peptide

Hexarelin

Potent GHRP with extra cardioprotective signaling via the CD36 receptor.

Educational explainer of a research peptide. Profiles in this section deliberately omit clinical-trial citations, dosing protocols, and purchase links. Not FDA-approved as a supplement; not a recommendation to use.

Overview

Hexarelin is a synthetic hexapeptide ghrelin-receptor agonist with the strongest acute GH response of the classic GHRPs and additional binding at CD36 in cardiac tissue.

Source
  • Synthesized in research laboratories
Forms
  • Subcutaneous injection
  • Intranasal (research)

Mechanism of action

Binds GHS-R1a for GH release and CD36 in cardiac tissue, supporting contractility and limiting ischemic damage in animal models.

Pathways
  • · GHS-R1a
  • · CD36 cardiac signaling
Receptors
  • · GHS-R1a
  • · CD36
Hormones
  • · GH
  • · IGF-1
  • · Cortisol
  • · Prolactin

How it acts on the body

Hexarelin produces the largest acute GH pulse of any classical GHRP, which paradoxically makes it the easiest to misuse: chronic high doses downregulate pituitary responsiveness and shrink subsequent natural pulses. Most modern protocols cycle it briefly rather than running it continuously.

Its second mechanism is independent of GH. Hexarelin binds CD36 in cardiac tissue, where animal data show reduced infarct size and preserved contractility after induced ischemia. This makes it interesting in cardiovascular research even when GH effects are stripped out, though human translation is unclear.

Hormonal & endocrine impact

How this peptide is reported to shift specific hormones and signaling molecules. Directionality reflects research literature and preclinical models, not clinical prescribing data.

Projected hormonal trajectory
Illustrative curves derived from reported direction of effect. Not measured patient data.

Curves are schematic shapes (sigmoid for increases/decreases, damped oscillation for modulation/stabilization) anchored to a 100% baseline. They communicate direction and tempo of change reported in research literature — not absolute hormone concentrations.

Growth hormoneIncreases
Largest acute GH pulse of the classical GHRPs.
CortisolIncreases
Notable rise, particularly at higher doses.
ProlactinIncreases
Comparable to GHRP-6.
IGF-1Increases
Sustained elevation with chronic dosing.

Effects on the body

Increases
GH pulse amplitude
Supports
Cardiac contractility (preclinical)
Inhibits
Long-term natural GH pulsatility at high doses

Organ system effects

Endocrine

Pituitary GH release with significant HPA activation.

Cardiovascular

CD36-mediated cardioprotective signaling in animals.

Reported effects

Drawn from preclinical research, anecdote, and small-scale clinical observation. No evidence grades are assigned — most peptides on this page lack rigorous human trials.

  • Strong acute GH response
  • Cardiac signaling of research interest

Potential side effects

Common
  • · Hunger
  • · Flushing
  • · Drowsiness
Rare
  • · Prolactin-related symptoms
Serious
  • · Pituitary desensitization with chronic use

Drug interactions

Other GH secretagogues
Compounded HPA and desensitization risk.
moderate

Pairing context

Often combined with
  • Short cycle protocols
    Limits desensitization.
Avoid combining with
  • Chronic daily dosing
    Blunts the very response it was used to enhance.
Important. Research peptides described here are not FDA-approved supplements. Supplement Scholar does not endorse, recommend, or link to any source for purchase. Consult a qualified clinician before considering any peptide therapy.