Hexarelin is a synthetic hexapeptide in the growth hormone releasing peptide (GHRP) family. In the research literature it is valued as a potent, well-characterized ligand for the growth hormone secretagogue receptor (GHS-R1a), and it has also drawn attention for binding to the scavenger receptor CD36. This page is a standalone overview of hexarelin as a laboratory reagent. If you are looking for comparisons, see Hexarelin vs Ipamorelin and Hexarelin vs CJC-1295.
Structure of Hexarelin
Hexarelin has the sequence His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2. It was derived from the earlier GHRP-6 scaffold, with the substitution of 2-methyl-D-tryptophan intended to improve stability. The two D-amino acids and the C-terminal amide are typical design choices that slow enzymatic breakdown in experimental systems.
The molecular weight is roughly 887 Da. Because the sequence includes a modified tryptophan, an observed mass from mass spectrometry is the simplest way to confirm a lot is genuinely hexarelin and not a closely related GHRP.
Receptor Research: GHS-R1a and CD36
GHS-R1a is the receptor for the endogenous hormone ghrelin, and hexarelin is one of several synthetic ligands used to characterize it. In receptor binding and signaling assays, hexarelin serves as a reference agonist that researchers can compare with other secretagogues such as ipamorelin or GHRP-2.
Separately, published work has identified CD36 as a hexarelin binding site in certain tissues in preclinical models. That has made hexarelin interesting to labs studying receptor pharmacology beyond the classic GH axis. These are preclinical, mechanistic findings.
Common Laboratory Research Themes
- Receptor binding assays: using hexarelin as a GHS-R1a reference ligand.
- Signal transduction: measuring downstream second-messenger responses in transfected cell lines.
- Receptor desensitization: studying how repeated ligand exposure changes receptor responsiveness in vitro.
- CD36 pharmacology: examining non-GHS-R binding in preclinical tissue models.
Hexarelin Specifications at a Glance
- Class: synthetic GHRP hexapeptide
- Sequence: His-D-2-Me-Trp-Ala-Trp-D-Phe-Lys-NH2
- Form: lyophilized powder
- Size: 5mg vial
- Verification: HPLC purity and mass spectrometry identity, third-party tested
Quality Documentation for Hexarelin
For any Hexarelin lot, the most useful document is the Certificate of Analysis. A credible COA identifies the lot number, the analytical method used for purity (typically reversed-phase HPLC with UV detection), the observed molecular mass from mass spectrometry, and the date of testing. If you are new to this, our guide on how to read a peptide Certificate of Analysis walks through each field, and our explainer on HPLC and mass spectrometry purity testing covers why the two methods are complementary.
Genetic Peptides USA lots are independently tested through PepAssure third-party verification, so the identity and purity numbers on the label can be traced back to a specific batch. Researchers comparing suppliers should confirm that the COA lot matches the vial lot, that the mass spectrum is consistent with the theoretical mass, and that purity is reported as a chromatographic area percentage rather than an unexplained single number.
Storage and Stability Considerations
Hexarelin is supplied as a lyophilized (freeze-dried) powder. In that form, peptides are generally most stable when kept cold, dry, and protected from light, and repeated temperature cycling should be avoided. Once a lyophilized peptide is brought into solution for an assay, stability characteristics change, so many labs prepare only what a given experiment requires and document preparation dates carefully. Our article on lyophilized peptide handling and storage covers general laboratory practices for freeze-dried research materials.
Where to Go Next
Review specifications on our Hexarelin 5mg research peptide page or browse the GH Axis Research collection for related GHRP and GHRH analogs. For a related standalone guide, see the Tesamorelin research peptide overview.
Frequently Asked Questions
What family does hexarelin belong to?
Hexarelin is a synthetic hexapeptide in the growth hormone releasing peptide (GHRP) family, derived from the GHRP-6 scaffold.
Which receptors does hexarelin bind in research?
Hexarelin is used as a reference ligand for GHS-R1a, the ghrelin receptor, and preclinical studies have also reported binding to the scavenger receptor CD36.
How is hexarelin different from GHRP-6?
Hexarelin substitutes 2-methyl-D-tryptophan into the GHRP-6 scaffold, a change intended to improve stability in experimental systems.
What should a hexarelin COA show?
A matching lot number, HPLC purity as an area percentage, and an observed mass consistent with roughly 887 Da.
Is this product for human or animal use?
No. It is supplied for laboratory research use only and is not for human or veterinary use. It is not a drug, food, or cosmetic and is not intended to diagnose, treat, cure, or prevent any disease.
All products referenced in this article are sold strictly for laboratory research use only. They are not for human or veterinary use, are not drugs, foods, or cosmetics, and are not intended to diagnose, treat, cure, or prevent any disease. Nothing here is guidance on administration or handling outside a qualified laboratory setting.