CJC-1295 — specifically in its No DAC (Drug Affinity Complex) form, also known as Modified GRF 1-29 or Mod GRF(1-29) — is a synthetic analog of the first 29 amino acids of endogenous human Growth Hormone-Releasing Hormone (GHRH). Four strategic amino acid substitutions at positions 2, 8, 15, and 27 relative to the native GHRH(1-29) sequence confer significantly enhanced proteolytic stability compared to the native peptide, while preserving high-affinity binding at the GHRH receptor (GHRHR). These properties have made CJC-1295 No DAC one of the most widely utilized GHRH analogs in GH axis research.
The "DAC" version of CJC-1295 incorporates a maleimidoproprionic acid modification enabling covalent albumin binding and dramatically extending the plasma half-life. The No DAC form produces discrete GH pulses more analogous to physiological GHRH pulsatility. This article covers the research profile of CJC-1295 (No DAC / Modified GRF 1-29) for laboratory research applications.
Biochemical Identity & Structural Properties
| Property | Value |
|---|---|
| Common Name | CJC-1295 No DAC / Modified GRF(1-29) |
| Full Description | GHRH analog with substitutions at positions 2, 8, 15, 27 |
| Molecular Weight | ~3,135 g/mol |
| CAS Number | 863288-34-0 |
| Classification | GHRH receptor agonist; synthetic peptide |
| Target Receptor | GHRHR (Growth Hormone-Releasing Hormone Receptor) |
| Solubility | Water-soluble; use sterile water or PBS for reconstitution |
| Storage (lyophilized) | −20°C, desiccated, light-protected |
Proposed Mechanisms of Action
GHRH Receptor Agonism & GH Release
CJC-1295 binds to GHRHR on somatotroph cells of the anterior pituitary with high affinity. GHRHR is a Gαs-coupled GPCR; agonist binding activates adenylyl cyclase, increases intracellular cAMP, and activates PKA — triggering GH exocytosis. The amino acid substitutions in CJC-1295 relative to native GHRH(1-29) protect against dipeptidyl peptidase IV (DPP-IV) cleavage at position 2 and endoprotease degradation at other vulnerable sites, substantially extending the half-life of biological activity compared to unmodified GHRH.
IGF-1 Axis Downstream Signaling
Research using rodent models has documented that GHRHR agonism by CJC-1295 produces downstream GH-dependent IGF-1 secretion from hepatocytes. The GH/IGF-1 axis has been studied extensively using CJC-1295 as a research tool for examining downstream signaling through the JAK2/STAT5b pathway, IGF-1R activation, and IRS-1 phosphorylation in cell-based metabolic research platforms.
GH Pulse Amplitude & Frequency Research
In GH axis research, CJC-1295 is frequently studied in combination with GHSR agonists such as Ipamorelin. Published research has examined how simultaneous GHRH receptor and GHSR-1a stimulation produces synergistic GH pulse amplification in rodent models — a research paradigm used to study pituitary somatotroph secretory dynamics and the dual-pathway regulation of GH release.
Summary of Published Research Findings
- Clinical pharmacology research: Ionescu et al. (2008) examined the pharmacokinetics and pharmacodynamics of CJC-1295 in a clinical research setting, documenting extended GH and IGF-1 elevations with favorable tolerability — establishing baseline data for the research community.
- GH axis modeling: CJC-1295 has been used extensively in rodent GH deficiency models to examine restoration of pulsatile GH secretion and downstream effects on somatic growth parameters, providing a research platform for GH axis biology.
- Combination paradigms: Studies examining CJC-1295 + Ipamorelin have characterized the synergistic relationship between GHRHR and GHSR-1a agonism in producing supraphysiological GH pulses in animal models.
- Body composition research: Animal model studies have examined the effects of GHRH analog administration on lean tissue accretion and fat metabolism, situating CJC-1295 within the GH axis / body composition research literature.
Key Published References
Ionescu M, Frohman LA. (2006). Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. Journal of Clinical Endocrinology & Metabolism, 91(12), 4792–4797. PMID: 16984990
Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. (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), 799–805. PMID: 16352683
Raun K, Hansen BS, Johansen NL, et al. (1998). Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology, 139(5), 552–561. PMID: 9849822
Storage & Laboratory Handling
- Lyophilized powder: −20°C in desiccated, light-protected conditions. Stable for 24+ months.
- Reconstitution: Use sterile water or 0.9% saline. Dissolves readily at room temperature.
- Post-reconstitution: Store at 2–8°C; use within 14 days. Avoid freeze-thaw cycles.
- Research note: For pituitary cell assays, CJC-1295 requires careful concentration optimization as receptor desensitization can occur with prolonged or supraphysiological exposure.
