Free shipping on orders over $200
Free shipping on orders over $200
Molecular Weight
Purity
Storage
Appearance
Solubility
01
Hexarelin (international non-proprietary name examorelin) is a synthetic six-residue growth hormone secretagogue developed in the early 1990s as a refined analogue of GHRP-6. It differs from GHRP-6 at a single position: the D-tryptophan at position 2 is replaced by D-2-methyl-tryptophan.
That one methyl group improves enzymatic stability and is associated with higher receptor potency than GHRP-6. Hexarelin is widely used as a tool compound for the ghrelin receptor (GHS-R1a), and separate work has identified the scavenger receptor CD36 as a second binding partner, which gives it a distinct place in cardiovascular signalling research. It is supplied as a lyophilized reference material for in vitro and analytical research only.
02
Hexarelin keeps the GHRP-6 framework, His-X-Ala-Trp-D-Phe-Lys-NH₂, and changes only residue 2.
D-2-methyl-Trp, position 2
A D-tryptophan carrying an extra methyl group on carbon 2 of the indole ring. The methyl adds hydrophobic surface for receptor contact and sterically hinders enzymatic cleavage near the N-terminus.
Trp, position 4
An unmodified L-tryptophan, so the molecule still has two indole rings and strong UV absorbance and fluorescence.
D-Phe, position 5
A D-configured aromatic residue shared with the rest of the GHRP family.
His1 and Lys6-NH₂
The N-terminal histidine and amidated C-terminal lysine are the same as in GHRP-6.
Because the change from GHRP-6 is a single CH₂ unit, the two peptides differ by about 14 Da and are a well-matched pair for structure–activity comparisons.
03
Published research describes Hexarelin acting at two distinct receptors.
Ghrelin receptor (GHS-R1a)
Hexarelin is a high-affinity agonist of this Gq-coupled receptor. In vitro, activation is measured through intracellular calcium release, inositol phosphate (IP₁) accumulation and, in pituitary cell preparations, growth hormone release.
CD36
Cross-linking and binding studies in cardiac membrane preparations identified the scavenger receptor CD36 as a separate binding site for Hexarelin, independent of GHS-R1a. This has made it a probe compound for non-GHS-R signalling in cardiac tissue models.
Comparative pharmacology
Studied alongside GHRP-6, GHRP-2 and Ipamorelin to relate sequence differences to differences in potency, selectivity and CD36 binding.
All research context described here refers to controlled in vitro and preclinical experimental systems.
04
GHS-R1a reference agonist
Used as a positive control in binding, calcium and IP₁ assays in receptor-expressing cell lines.
Pituitary cell assays
A stimulation control in dispersed pituitary cell preparations measuring growth hormone release.
CD36 research
A probe ligand in isolated cardiomyocyte and cardiac membrane studies of CD36-mediated signalling.
Structure–activity comparisons
Paired with GHRP-6 to isolate the effect of the 2-methyl group, and compared with GHRP-2 and Ipamorelin across the secretagogue series.
05
Storage
Store the lyophilized powder at −20 °C, sealed, desiccated and protected from light. Let the vial reach room temperature before opening.
Light and oxygen
The two tryptophan residues can oxidise, especially under light. Use amber or opaque containers and minimise air exposure of solutions.
Reconstitution
Dissolves readily in water or dilute acetic acid (about 0.01–0.1 M) with gentle swirling.
Solutions
Keep working solutions cold and use them promptly. For longer storage, freeze single-use aliquots and avoid repeated freeze–thaw cycles. Discard any solution that becomes cloudy.
Salt form
Material is commonly supplied as the acetate salt. Correct for counter-ion content (reported on the certificate of analysis) when calculating peptide concentration.
06
Hexarelin is analysed with the same methods used for GHRP-6, with attention to separating the two when both are present.
HPLC
Reversed-phase C18 with a 0.1% TFA water/acetonitrile gradient. The extra methyl group makes Hexarelin slightly more hydrophobic than GHRP-6, so the two separate under matched conditions. Detect at 214–220 nm or at 280 nm for the tryptophans.
Mass spectrometry
ESI-MS in positive mode shows [M+H]⁺ at m/z 887.5 (monoisotopic mass 886.46 Da), about 14 Da above GHRP-6. MS/MS b- and y-ions confirm the sequence and the position of the methylated residue.
Peptide content
Acetate content is measured separately, for example by ion chromatography, so that true peptide content can be calculated.
Impurity profile
Typical checks cover tryptophan oxidation products, histidine oxidation, L-epimers at positions 2 and 5, truncated sequences and the non-amidated free acid.
07
Only at position 2: Hexarelin has D-2-methyl-tryptophan where GHRP-6 has D-tryptophan. This adds 14 Da, increases stability against enzymes and is associated with higher receptor potency.
On carbon 2 of the indole ring of the D-tryptophan at position 2. It is a C-methyl group, not an N-methylation of the backbone or the indole nitrogen.
Binding and cross-linking studies in cardiac membrane preparations identified the scavenger receptor CD36 as a second binding site for Hexarelin, separate from the ghrelin receptor. It is therefore used as a probe in CD36 signalling research.
By mass, since Hexarelin is about 14 Da heavier ([M+H]⁺ at m/z 887.5 versus 873.4), and by reversed-phase HPLC, where the extra methyl group makes Hexarelin elute slightly later.
No. It is supplied strictly as a reference compound for laboratory and analytical research and is not for human or animal use.
Hexarelin Research Reference. (2026). Pure Peptides Labs Research Catalogue. Retrieved from https://purepeptideslabs.net/research-catalogue/growth-hormone-axis-research-peptides/hexarelin/
Materials listed on this platform are supported by independent testing and published documentation for laboratory research contexts.
