CJC-1295 (no DAC)

Overview

CJC-1295 (no DAC), also known as Modified GRF (1-29) or Mod GRF, is a synthetic analog of the first 29 amino acids of growth hormone-releasing hormone (GHRH). This modified peptide was designed with four amino acid substitutions at positions 2, 8, 15, and 27 to enhance metabolic stability while preserving full biological activity at the GHRH receptor.

The modifications replace DPP-IV-susceptible residues and enzymatically labile amino acids with more resistant alternatives, extending the peptide's half-life from the natural GHRH(1-29)'s approximately 5-7 minutes to approximately 30 minutes. This "no DAC" version lacks the Drug Affinity Complex, resulting in pulsatile rather than sustained GH release.

CJC-1295 without DAC is particularly valued in research for its ability to produce physiological pulsatile GH release patterns, mimicking the natural secretory rhythm of the hypothalamic-pituitary axis.

Chemical Profile

Mechanism of Action

CJC-1295 (no DAC) acts as a full agonist at the GHRH receptor (GHRH-R) on anterior pituitary somatotroph cells. Upon binding, it activates the Gs protein-coupled adenylyl cyclase pathway, increasing intracellular cAMP levels. This cAMP elevation activates protein kinase A (PKA), which phosphorylates multiple downstream targets including CREB (cAMP response element-binding protein).

The CREB activation leads to transcriptional upregulation of the growth hormone gene, increasing GH mRNA synthesis and protein production. Simultaneously, the cAMP/PKA pathway promotes calcium influx through voltage-gated calcium channels, triggering immediate GH vesicle exocytosis.

The amino acid substitutions at positions 2 (D-Ala), 8 (Gln), 15 (Ala), and 27 (Leu) protect the peptide from enzymatic cleavage by DPP-IV and other serum proteases while maintaining the critical N-terminal residues required for receptor recognition and activation.

Research Applications

• Pulsatile GH release pattern research
• GHRH receptor agonism and signaling
• Synergistic effects with GHS-R1a agonists (e.g., Ipamorelin)
• Body composition and metabolic research
• Sleep quality and GH secretion studies
• Age-related GH decline models

Handling & Reconstitution

1. 1Allow the vial and sterile water to reach room temperature (15–25°C).
2. 2Using a sterile syringe, withdraw the appropriate volume of sterile water.
3. 3Inject the water slowly along the inside wall of the vial — do not spray directly onto the powder.
4. 4Gently swirl the vial until the powder is fully dissolved. Do not shake vigorously.
5. 5Once reconstituted, store at 2°C – 8°C. Protect from light.
6. 6Use within 28 days after reconstitution.
7. 7Do not freeze reconstituted solution.