CJC-1295: Mechanism & Published Research
CJC-1295 (also designated Mod GRF 1-29 in its DAC-free form) is a synthetic analog of the first 29 amino acids of endogenous growth hormone-releasing hormone (GHRH 1-29). The compound was developed to improve upon the bioavailability of native GHRH 1-44, which has a very short plasma half-life of approximately two minutes due to rapid DPP-4 cleavage and renal clearance.
In the published pharmacology literature, the DAC-free form (Mod GRF 1-29) is characterized by four amino acid substitutions relative to native GHRH 1-29 that confer resistance to DPP-4 degradation, extending the biological half-life to approximately 30 minutes following subcutaneous injection in pharmacokinetic studies. This half-life supports the pulsatile research protocols investigators use to study physiological GH secretion patterns.
The DAC (Drug Affinity Complex) form of CJC-1295 incorporates a lysine-maleimide modification that enables covalent binding to serum albumin, dramatically extending the half-life to approximately eight days in published human pharmacokinetic studies. This extended-release formulation produces a sustained elevation of GH and IGF-1 baseline levels — a distinctly different pharmacodynamic profile from the pulsatile pattern of the DAC-free form — and is studied in different experimental contexts.
Researchers examining the somatotropic axis have studied CJC-1295 extensively in combination with GHS-R1a agonists, particularly ipamorelin, to produce synergistic GH pulse amplitude increases in animal models. Investigators have reported dose-dependent increases in plasma GH and IGF-1 concentrations in rodent models, with the GHRH + GHRP combination more closely recapitulating physiological GH secretion patterns than either compound alone.
Canada Peptide Supply offers CJC-1295 in both the with-DAC form (5 mg/vial) and the without-DAC form (5 mg/vial), as well as the pre-blended CJC-1295 + Ipamorelin stack (10 mg + 5 mg/vial). All are verified at ≥99% purity by HPLC and mass spectrometry with COA on every batch. Neither form is approved by Health Canada for human therapeutic use.