What GHRP-6 is
GHRP-6 is a synthetic hexapeptide and the compound that effectively founded the growth-hormone-secretagogue field. Its sequence, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2, contains two D-amino acids — mirror-image residues that natural enzymes are poor at cleaving. That substitution is a standard trick for making a short peptide survive long enough to be useful, and GHRP-6 is one of the cleaner illustrations of it.
- GHRP-6Hexapeptide secretagogue
- GHSR-1aThe ghrelin receptor
- Gq → PLC → Ca²⁺Also drives the appetite arm of ghrelin signalling
- GH and food-intake modelsPreclinical
Mechanism as described in published research. Nothing here describes an effect in a person — these compounds are supplied for laboratory research use only.
Ghrelin receptor and appetite signalling
Like GHRP-2, GHRP-6 is an agonist at GHS-R1a. Its distinguishing feature in the literature is a more pronounced association with appetite signalling — unsurprising once ghrelin was identified as the endogenous ligand, since ghrelin is centrally involved in hunger regulation.
That makes GHRP-6 a useful tool in two literatures at once: growth-hormone axis work, where it is one probe among several, and feeding-behaviour research, where the ghrelin system is the subject rather than the route. Study designs interested in the GH axis alone often prefer ipamorelin precisely because it lacks that second dimension.
What the literature covers
Research areas include:
- Ghrelin receptor pharmacology — GHRP-6 as the original reference agonist.
- Appetite and feeding-behaviour models.
- D-amino acid substitution as a stability strategy.
- Comparative selectivity across the secretagogue class.
Identity and verification
GHRP-6 has the molecular formula C46H56N12O6 and a molecular weight of 873.0 g/mol (CAS 87616-84-0). Identifiers matter more here than in most categories: research compounds are sold under trade names, development codes and abbreviations that do not always refer to the same molecule, and a formula is unambiguous where a name is not.
Every lot is tested by an independent laboratory before release. Our certificate library covers the lots currently in stock.
We use two laboratories because purity and identity are different questions. Vanguard Laboratory is ISO/IEC 17025:2017 accredited (A2LA #6377.01.01) and reports chromatographic purity and net quantity with a stated measurement uncertainty. Freedom Diagnostics reports HPLC-UV purity together with LC-MS identity confirmation — the test that catches a substituted compound rather than merely an impure one. A sample can be 99% pure and still be the wrong molecule. How we test →
Handling, reconstitution and storage
GHRP-6 ships lyophilized — freeze-dried to a solid and sealed under vacuum — which is what makes it stable in transit rather than a solution racing a clock. Reconstitute with bacteriostatic water, added slowly down the inside wall of the vial rather than directly onto the powder, then swirled gently. Do not shake: mechanical shear is one of the few things that reliably degrades a peptide in the lab.
Final concentration is a function of the volume added, not of the compound, so the same vial can be prepared at very different concentrations. The reconstitution calculator works out the volume for a target concentration and the reconstitution guide covers the procedure. Store lyophilized vials at −20 °C (−4 °F) protected from light; refrigerate once in solution, and see the storage and stability guide for how long reconstituted material holds.
Common questions
What does GHRP-6 stand for?
Growth Hormone Releasing Peptide-6. It is a synthetic hexapeptide and the compound that effectively founded the growth-hormone-secretagogue field.
Why does GHRP-6 contain D-amino acids?
D-amino acids are mirror images of the natural L-form, and enzymes are poor at cleaving them. Including two in a six-residue peptide is what allows it to survive long enough to be a usable research tool.
Why is GHRP-6 associated with appetite?
It acts at the ghrelin receptor, and ghrelin is centrally involved in hunger regulation. GHRP-6 shows that association more prominently than the more selective secretagogues.
Which secretagogue is best for isolating the GH axis?
Ipamorelin, generally — it was developed specifically to remove the cross-activity the earlier GHRP compounds show, so it produces a narrower stimulus.
Where to get it
Buy research-grade GHRP-6 — independently tested, certificate published, shipped from Miami with cold-chain packaging. Current pricing for every size is on the price list, and we ship worldwide.
Research use only
Everything referenced here is supplied strictly for laboratory research. These compounds are not drugs, foods, cosmetics or medical devices, are not for human or veterinary use, and are not approved for diagnostic or therapeutic application. Mechanisms are described as studied in preclinical and laboratory research; nothing above describes dosing, treatment or clinical outcome.
