GHRP-2 - Frequently Asked Questions

GHRP-2 is a synthetic hexapeptide growth hormone secretagogue (GHS) and an agonist of the growth hormone secretagogue receptor type 1a (GHS-R1a), the same class A G-protein-coupled receptor that binds endogenous ghrelin. It is studied as a ghrelin mimetic in in-vitro receptor and cell systems.

The sequence is D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH2, also written as D-Ala-D-beta-(2-naphthyl)-Ala-Ala-Trp-D-Phe-Lys-amide. It is a six-residue peptide that incorporates non-natural and D-configured residues and carries a C-terminal amide.

The free peptide base has a molecular formula of C45H55N9O6 and an average molecular weight of 817.99 g/mol (Wikipedia lists 817.992 g/mol). The 817.99 g/mol value is the constant used to convert a weighed mass into molar concentration for in-vitro assays.

The CAS Registry Number for the free peptide base is 158861-67-7. This identifier uniquely distinguishes the compound across chemical databases independent of its various names.

Yes. GHRP-2 is also known as pralmorelin and corresponds to CAS 158861-67-7. It is noted as having been marketed in Japan as a diagnostic agent under the designation GHRP Kaken 100. Recognizing the synonym is useful when assembling the literature record.

Its primary target is GHS-R1a, a Gq/11-coupled GPCR. In receptor-expressing cells and isolated anterior pituitary somatotroph preparations, receptor engagement activates phospholipase C, generating IP3 and diacylglycerol, which mobilizes intracellular Ca2+ and activates protein kinase C, with reported PKA/cyclic-AMP contributions in some pituitary models. The net output is depolarization and Ca2+-driven secretory-granule exocytosis.

The GHS-R1a antagonist [D-Lys3]-GHRP-6 blocks GHRP-2 effects in C2C12 myocyte models, as reported by Yamamoto et al. (Life Sciences 2008). Because a selective antagonist abolishes the response, the activity is confirmed to proceed through GHS-R1a rather than an off-target route.

The cited literature covers GHS-R1a binding and agonist pharmacology in receptor-transfected cell lines, Gq/11-PLC/IP3-DAG/Ca2+/PKC signal-transduction studies, in-vitro anterior pituitary secretory-cell models, receptor-specificity profiling in cultured C2C12 myocytes, and comparative structure-activity work within the GHS/ghrelin-mimetic class. The receptor itself was characterized by Howard et al. (Science 1996).

No specific half-life, clearance, or degradation-rate number is provided in the data. The record includes a pharmacokinetic and pharmacodynamic characterization (Pihoker et al., JCEM 1998), but any quantitative parameter would need to be read from that source rather than stated here. Its D-amino-acid-containing, C-terminally amidated structure is, as a general class principle, associated with resistance to proteolysis.

Lyophilized GHRP-2 is dissolved in a sterile diluent, conventionally bacteriostatic water, added slowly down the vial wall and mixed by gentle swirling. The diluent volume sets the concentration; the molecular weight of 817.99 g/mol converts mass to molar units. This is laboratory in-vitro preparation only, not a human dosing protocol.

The lyophilized powder is the most stable form and is kept cold and desiccated. Reconstituted solution is refrigerated for short-term use or frozen for longer storage, and aliquoted to avoid repeated freeze-thaw cycles that can degrade peptide integrity. Stocks are inspected for clarity before use and discarded if cloudy.

No. All information here describes in-vitro receptor binding, intracellular signal-transduction events, and laboratory handling for research use only. The content does not describe or support human dosing, therapeutic, or disease-treatment applications.