Hexarelin Acetate

Product definition

What is Hexarelin Acetate?

Hexarelin (Examorelin) is the most potent characterized GHRP hexapeptide — GHS-R1a agonist with Phase II human data and unique CD36 cardiac receptor binding providing GH-independent cardioprotection in animal models.

Hexarelin (His-D-2-MeTrp-Ala-Trp-D-Phe-Lys-NH2; Examorelin) is a synthetic hexapeptide GH secretagogue developed by Europeptides SA (France) and licensed to Pharmacia for clinical development. The 2-MeTrp (2-methyltryptophan) substitution at position 2 relative to GHRP-6 is primarily responsible for the increased potency compared to the parent compound. Phase I/II clinical development was conducted by Pharmacia for GH deficiency indications, producing published human pharmacokinetic data and dose-response characterization that is available in the research literature. Development was discontinued before regulatory submission for commercial reasons, leaving a compound with the most complete clinical pharmacokinetic characterization of any research GHRP that did not reach approval. The CD36 binding was identified during mechanistic characterization of hexarelin's cardioprotective effects in animal ischemia models. CD36 is a class B scavenger receptor expressed on cardiomyocytes, macrophages, and endothelial cells. Hexarelin's GH-independent cardiac effects — reduced infarct size, preserved ejection fraction in myocardial ischemia models — have been attributed to CD36-mediated signaling rather than GHS-R1a activation, establishing hexarelin as a dual-receptor research tool.

Research context

What does the preclinical literature say about Hexarelin Acetate?

Hexarelin's development history tracks alongside the broader GHRP class: discovered in the context of systematically modifying GHRP-6 for increased potency, taken through animal pharmacology and into human Phase II research, then discontinued before approval as the GH secretagogue field consolidated around different therapeutic approaches. The Phase II dataset remains in the published literature and constitutes the most rigorous human pharmacokinetic characterization available for a GHRP-class compound outside Japan (where GHRP-2/Pralmorelin is approved). The CD36 discovery was significant: it identified that hexarelin's cardioprotective effects in ischemia models were not abolished by GH receptor antagonism — ruling out an IGF-1-mediated cardioprotection pathway and implicating CD36 directly. Subsequent studies in CD36-null mice confirmed that the cardioprotective effects were CD36-dependent, establishing this receptor as a pharmacological target for peptide-based cardiac intervention research. This cardiac biology dimension has made hexarelin relevant to a different research community than standard GHRPs — cardiovascular researchers studying ischemic preconditioning, cardiac repair, and scavenger receptor biology have incorporated hexarelin as a pharmacological probe for CD36's role in cardiomyocyte survival and stress response.