Mechanism of Action

Research indicates that CJC-1295 acts as an agonist at the growth-hormone-releasing hormone receptor (GHRHR) on pituitary somatotrophs, promoting the synthesis and pulsatile release of growth hormone (GH). CJC-1295 is a synthetic analog of GHRH(1-29); the drug-affinity-complex (DAC) variant incorporates a reactive linker that covalently binds circulating albumin after administration, and studies in healthy adults reported prolonged elevation of GH and downstream IGF-I lasting several days from a single dose. This extended pharmacokinetic profile is the principal feature distinguishing CJC-1295 from native GHRH, whose plasma half-life is measured in minutes.

Ipamorelin is described in the literature as a selective agonist of the growth-hormone secretagogue receptor (GHS-R1a), the same receptor targeted by the endogenous ligand ghrelin. Acting through this ghrelin-mimetic pathway, it stimulates GH release via a mechanism distinct from GHRH-receptor signaling, and preclinical work characterized it as releasing GH with potency comparable to GHRP-6 while showing minimal effect on ACTH and cortisol. Because a GHRH analog and a GHS-R agonist engage separate receptors on the somatotropic axis, research often examines the two in combination to study potentially additive or synergistic effects on GH secretion dynamics. These descriptions summarize mechanistic and preclinical findings and are not claims of clinical benefit.

Research Applications

• → In a placebo-controlled study of healthy adults, a single subcutaneous dose of CJC-1295 increased mean plasma GH concentrations 2- to 10-fold for six or more days and IGF-I concentrations 1.5- to 3-fold for 9-11 days (Teichman et al., 2006).
• → The drug-affinity-complex (DAC) modification of CJC-1295 promotes covalent binding to endogenous albumin, extending circulating half-life from the minutes-long range of native GHRH to a multi-day window in research models.
• → Ipamorelin was characterized in preclinical work as the first selective GH secretagogue, releasing GH with potency and efficacy similar to GHRP-6 in rat pituitary cells and in conscious swine (Raun et al., 1998).
• → In the same preclinical characterization, Ipamorelin did not raise ACTH or cortisol above GHRH-stimulated levels even at doses more than 200-fold above the ED50 for GH release, indicating receptor selectivity.
• → In a GHRH-knockout mouse model, once-daily CJC-1295 normalized body weight and length, demonstrating restoration of the GH/IGF-I growth axis in an animal lacking endogenous GHRH (Alba et al., 2006).

Analytical Validation

CJC-IPA is verified via LC-MS and HPLC analysis. Each lot is tested for identity, purity (≥99% target), and endotoxin levels. Full certificate of analysis is available upon request.