CJC-1295 + Ipamorelin

This is a single vial containing two distinct growth hormone secretagogues, CJC-1295 without DAC and Ipamorelin, supplied pre-blended at 5mg of each. The two act on separate receptors, which is the entire reason they are studied together rather than as alternatives to one another.

CJC-1295 without DAC is more precisely described as tetrasubstituted GRF(1-29), a 29-amino-acid fragment of growth hormone releasing hormone carrying four substitutions (D-Ala at position 2, Gln at 8, Ala at 15 and Leu at 27). The substitution at position 2 is the functionally important one: it blocks cleavage by dipeptidyl peptidase-4, the protease that degrades native GRF within minutes. It binds the GHRH receptor on the pituitary somatotroph and signals through the cAMP/PKA pathway. Because it lacks the drug affinity complex, it does not covalently bind serum albumin and its action remains short, which is precisely what makes it useful for studying pulse shape rather than sustained elevation.

Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) that acts at a completely different target, the ghrelin receptor GHS-R1a. Raun and colleagues (Eur J Endocrinol, 1998) characterised it as the first growth hormone releasing peptide with selectivity approaching that of GHRH itself, reporting growth hormone release without the accompanying ACTH and cortisol elevation seen with earlier compounds in the class such as GHRP-6 and hexarelin. That selectivity is the single most cited property of the molecule.

Pairing a GHRH analogue with a GHS-R1a agonist is a long-standing design in secretagogue research, following the work of Bowers and colleagues showing that the two classes produce a greater combined response than either alone. The usual mechanistic explanation is that the GHRH arm drives somatotroph cAMP signalling while the GHRP arm additionally attenuates somatostatin tone, so the two are acting on different limbs of the same axis rather than competing for one receptor. Supplied as lyophilised powder for in-vitro laboratory research only.