CJC-1295

CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH) engineered for prolonged pharmacokinetic activity through two complementary strategies. First, four amino acid substitutions in the GHRH(1-29) backbone (D-Ala at position 2, Gln at position 8, Ala at position 15, Leu at position 27) protect against enzymatic degradation at key protease cleavage sites. Second, a Drug Affinity Complex (DAC) technology maleimido-propionyl group is attached at a C-terminal Lys30 residue; upon subcutaneous administration, this reactive group covalently bonds to circulating albumin, effectively using albumin as a half-life extension vehicle. The result is a plasma half-life of approximately 6–8 days, enabling once-weekly or less frequent dosing versus the 5–7 minute half-life of native GHRH. CJC-1295 binds and activates GHRH receptors on pituitary somatotroph cells via the same mechanism as native GHRH, stimulating GH synthesis and pulsatile secretion. Importantly, the albumin-conjugated form produces sustained GH elevation over days — maintaining elevated mean GH levels while preserving pulsatile superimposition — rather than the sharp transient spikes produced by shorter-acting GHRH analogs. Phase I/II clinical studies demonstrated that a single injection of 2 mg/kg CJC-1295 produced mean serum GH increases of 2–10 fold sustained over 6 days, with parallel IGF-1 elevations of 1.5–3 fold persisting for 9–11 days. Research applications include GH deficiency, aging-associated somatopause, body composition optimization (lean mass gain, visceral fat reduction), wound healing, bone mineral density, and metabolic syndrome. CJC-1295 is frequently studied in combination with ipamorelin (GHSR-1a agonist) to produce synergistic GH release through complementary receptor pathways, combining GHRH receptor stimulation with ghrelin receptor activation.