CJC-1295: Pharmacologic Actions and Effects
CJC-1295 is a synthetic, long-acting growth hormone-releasing hormone (GHRH) analog that covalently binds to serum albumin via a maleimido group, resulting in sustained stimulation of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) secretion for 6-11 days after a single injection. 1
Mechanism of Action
CJC-1295 contains a strategically placed maleimidopropionic acid group at its C-terminus that covalently binds to the free thiol on Cys34 of endogenous serum albumin, creating a stable bioconjugate that dramatically extends its plasma half-life to 5.8-8.1 days compared to native GHRH. 2, 1
The albumin-bound peptide activates GHRH receptors on anterior pituitary somatotropes, stimulating both synthesis and pulsatile release of GH. 2
The drug maintains normal GH pulsatility while markedly increasing basal (trough) GH levels by 7.5-fold, which appears critical for sustained IGF-1 elevation. 3
Pharmacokinetic Profile
After subcutaneous injection, CJC-1295 produces dose-dependent increases in mean plasma GH concentrations by 2- to 10-fold for 6 days or more. 1
Mean plasma IGF-1 concentrations increase 1.5- to 3-fold for 9-11 days after a single injection, with levels remaining above baseline for up to 28 days after multiple doses. 1
Western blot analysis confirms CJC-1295 immunoreactive species appear on the albumin band within 15 minutes and remain in circulation beyond 24-72 hours. 2
Physiologic Effects
In healthy adults aged 21-61 years, CJC-1295 at doses of 30-60 mcg/kg demonstrated sustained GH and IGF-1 elevation with preserved GH pulsatility and was safe and relatively well tolerated. 1
In GHRH knockout mice, once-daily administration of CJC-1295 normalized body weight, length, femur and tibia length, lean mass, and subcutaneous fat mass, demonstrating its ability to restore normal growth when endogenous GHRH is absent. 4
The drug increases total pituitary RNA and GH mRNA, suggesting proliferation of somatotroph cells occurs with treatment. 4
Proteomic Changes
CJC-1295 administration produces measurable serum protein profile changes including decreased apolipoprotein A1 and transthyretin isoforms, and increased beta-hemoglobin and C-terminal albumin fragments. 5
A linear relationship exists between certain protein fragments (immunoglobulin and albumin) and IGF-1 levels, representing potential biomarkers of GH/IGF-1 action. 5
Safety Profile
Reported adverse reactions include anaphylactoid reaction, drowsiness, dry mouth, headache, fatigue, vomiting, and rarely blurred vision. 6
No serious adverse reactions were reported in clinical trials, and the drug was particularly well tolerated at doses of 30-60 mcg/kg. 1
Clinical studies establishing safety and effectiveness in children have not been done; therefore, usage is not recommended in children under 12 years of age. 6
Regulatory Status
CJC-1295 is prohibited by the World Anti-Doping Agency (WADA) for use in sports, though detection in anti-doping samples has been challenging due to its albumin conjugation and low urinary concentrations. 7, 8
The drug represents an unapproved use of GH-axis manipulation, as current endocrinology guidelines only support approved recombinant human GH preparations for documented GH deficiency. 9
Clinical Context
While CJC-1295 demonstrates robust pharmacologic activity in stimulating the GH/IGF-1 axis, it lacks FDA approval for therapeutic use and should not be confused with established medical treatments for acromegaly or GH deficiency, which utilize somatostatin receptor ligands, dopamine agonists, or GH receptor antagonists for acromegaly 10, and approved recombinant human GH for documented GH deficiency 9.