Also known as: CJC-1295 DAC · Modified GRF(1-29) · Drug Affinity Complex GHRH
CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH) with a Drug Affinity Complex (DAC) modification that enables albumin binding in the bloodstream, extending its half-life from minutes to 6–8 days. It acts at the pituitary to increase GH pulse frequency and baseline IGF-1 levels.
CJC-1295 was developed by ConjuChem Biotechnologies as a long-acting GHRH analog for clinical investigation in GH deficiency. The key innovation is the DAC technology — a maleimide group attached to lysine at position 8 that reacts spontaneously with the free thiol groups of circulating albumin, creating a stable covalent bond that protects the peptide from enzymatic degradation and renal clearance.
While the DAC version offers extended dosing convenience (once or twice weekly), a non-DAC version (Modified GRF 1-29, or "Mod GRF") is also widely used, offering a shorter 30-minute window of GH elevation that more closely mirrors physiological GH pulses. The choice between DAC and non-DAC versions depends on the desired GH secretion pattern.
CJC-1295 binds to and activates GHRH receptors (GHRHR) on anterior pituitary somatotrophs with higher affinity than endogenous GHRH. Receptor activation triggers cAMP-dependent protein kinase A signaling, increasing both GH synthesis and secretory pulse amplitude.
Sustained GHRHR stimulation by CJC-1295 DAC raises baseline IGF-1 (Insulin-like Growth Factor 1) by 200–400% in clinical studies. IGF-1, produced primarily in the liver, mediates the anabolic effects of GH — muscle protein synthesis, lipolysis, and bone density maintenance.
CJC-1295 stimulates pituitary GH release rather than providing exogenous GH, preserving the natural pulsatile release pattern. This is a key safety advantage over synthetic HGH. IGF-1 levels should be monitored during longer cycles. Water retention and mild fatigue are common initial effects that typically resolve within 2–3 weeks.
Longer cycles (up to 6 months) are used in research contexts with regular IGF-1 monitoring. The off-cycle allows pituitary sensitivity to reset and prevents downregulation of endogenous GHRH receptors. IGF-1 levels typically return to baseline within 4 weeks of cessation.
Elevated IGF-1 beyond normal physiological ranges over extended periods is theoretically associated with increased cellular proliferation risk. Monitor IGF-1 levels and consult a physician for cycles longer than 12 weeks.
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