Overview

CJC-1295 is a synthetic GHRH analogue based on the first 29 residues of human GHRH, with four amino-acid substitutions that increase its resistance to enzymatic degradation. The “with DAC” (Drug Affinity Complex) version carries a maleimidopropionic-acid linker that covalently binds to circulating serum-albumin cysteine-34, converting a short-acting GHRH analogue into one with a half-life measured in days rather than minutes.

The parent CJC-1295 molecule was investigated in Phase I and Phase II human trials by ConjuChem in the 2000s for growth-hormone deficiency, HIV lipodystrophy, and adult muscle wasting; the program was discontinued and no marketed drug resulted. It remains a research chemical.

Mechanism (as reported)

  • GHRH-receptor agonism. CJC-1295 binds and activates the GHRH receptor on somatotroph cells of the anterior pituitary, producing episodic release of endogenous growth hormone.
  • Preserved pulsatile GH release. Because CJC-1295 amplifies rather than replaces the endogenous GH pulse, studies indicate the physiological pulsatile pattern is preserved — in contrast to direct exogenous GH administration.
  • Extended half-life via albumin binding. The DAC linker covalently binds serum albumin, giving CJC-1295 with DAC a reported half-life of approximately 6–8 days in humans (Teichman et al., 2006).

Research findings

  • Teichman et al. (2006) reported that a single subcutaneous dose of CJC-1295 with DAC (30–250 mcg/kg) produced sustained increases in mean serum GH and IGF-1 over multiple days in healthy adult subjects. Peak IGF-1 increases were dose-dependent.
  • The pulsatile pattern of GH secretion was reported to be preserved, though pulse amplitude and mean concentration were elevated.
  • CJC-1295 with DAC is typically discussed in combination with a growth-hormone secretagogue such as Ipamorelin — the two act on distinct receptors (GHRH-R and the ghrelin/GHS-R), and their combined effect on GH release is greater than either alone in preclinical work.

Common dosing (animal studies and Phase I data)

Reported research doses commonly fall between 1,000 and 2,000 mcg per administration, once or twice weekly, given the ~1-week half-life. Because IGF-1 rises accumulate over the first several doses, weekly dosing is the most frequently discussed pattern in the literature.

Reconstitution

A common reconstitution reported in the literature is 2 mg of peptide in 2 mL bacteriostatic water, producing a 1,000 mcg/mL solution. A 1,000 mcg (1 mg) research dose corresponds to 1.0 mL, or 100 units on a U-100 insulin syringe.

Storage

Lyophilised CJC-1295 with DAC is generally reported as stable at room temperature for shipping. Once reconstituted, the peptide is typically stored refrigerated at 2–8 °C.

Notes on nomenclature

The name “CJC-1295” without the DAC modification refers to a short-acting variant (sometimes called “Mod GRF 1-29” or “CJC-1295 no-DAC”), which has a much shorter half-life measured in minutes and produces short GH pulses. These are pharmacologically distinct compounds and should not be confused.

Common stacks

  • GH Pulse Stack — paired with Ipamorelin as the reference GHRH-analog + ghrelin-mimetic combination.

References

  • Teichman, S. L., et al. (2006). “Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults.” Journal of Clinical Endocrinology & Metabolism, 91(3). PMID 16352683.
  • Ionescu, M. & Frohman, L. A. (2006). “Pulsatile secretion of growth hormone stimulated by continuous administration of a growth hormone releasing hormone analog.” Journal of Clinical Endocrinology & Metabolism, 91(12). PMID 16968793.
  • Sackmann-Sala, L., et al. (2009). “Growth hormone-releasing hormone (GHRH) analogs.” Growth Hormone & IGF Research, 19(6). PMID 19733097.