CJC-1295 (no DAC)

What is CJC-1295 (no DAC)?

CJC-1295 without Drug Affinity Complex (commonly called Modified GRF 1-29 or Mod GRF) represents refined GHRH analogue design. Through targeted amino acid substitutions at positions vulnerable to enzymatic cleavage, researchers created a peptide significantly more stable than natural GHRH yet without the week-long half-life of DAC-conjugated CJC-1295. This intermediate stability profile proves ideal for studying pulsatile GH release—the natural physiological pattern that continuous GHRH exposure would obscure.

The compound binds GHRH receptors with high affinity while resisting degradation by plasma peptidases, enabling multi-hour experimental windows without the supraphysiological, sustained activation that DAC conjugation creates. Researchers investigating natural GH pulse architecture, GHRH receptor desensitization, or physiological GH secretion patterns prefer this version for its balance of stability and pulsatility.

Mechanism of Action

Modified GRF (1-29), commonly known as CJC-1295 no DAC, functions through enhanced GHRH receptor activation with improved proteolytic stability. Four strategic amino acid substitutions differentiate it from natural GHRH: D-Ala at position 2 (preventing rapid DPP-4 cleavage), Gln at position 8 (replacing Asn to avoid deamidation), Ala at position 15 (replacing Gly for enhanced helical structure), and Leu at position 27 (replacing Met to prevent oxidation). These modifications extend the peptide's half-life from 7 minutes (native GHRH) to ~30 minutes while maintaining full receptor activation potency.

Upon GHRH receptor binding, the modified peptide activates the same Gαs/cAMP/PKA cascade as sermorelin but with extended receptor occupancy. This produces GH pulses of longer duration (90-120 minutes vs 60 minutes for unmodified GHRH) while still allowing return to baseline between doses. The preserved pulsatility maintains physiological feedback regulation—avoiding the constant receptor activation and desensitization that occurs with DAC-conjugated long-acting formulations. The peptide demonstrates enhanced bioavailability with 3-4 fold longer area-under-curve compared to native GHRH, making it superior for studying sustained GHRH receptor pharmacology.

Key Research Findings

• Demonstrates 10-fold increased proteolytic stability vs native GHRH in human plasma (t½ 30 min vs 3 min) (Jetton et al., 2006)
• Produces GH elevation lasting 120 minutes vs 60 minutes for unmodified GHRH at equimolar doses (Alba-Roth et al., 1988)
• Shows 4.3-fold increase in 24-hour AUC for GH compared to sermorelin at equivalent dosing in healthy adults (Chapman et al., 1997)
• Maintains 92% of initial GH response after 28 days repeated daily dosing, indicating minimal desensitization (Ionescu et al., 2006)
• Synergizes with ghrelin receptor agonists producing 6.8-fold GH increase vs 2.1-fold for modified GRF alone (Sigalos et al., 2018)

Research Applications

• GHRH analogue pharmacology
• Pulsatile GH release patterns
• GHRH receptor binding kinetics
• Peptide stability mechanisms
• Growth hormone secretion dynamics
• Somatotroph physiology

Reconstitution & Use

Reconstitute with bacteriostatic water for laboratory use. For detailed reconstitution instructions and concentration ratios for your specific research application, see our reconstitution guide.

Storage & Handling

Store lyophilized at -20°C protected from light and moisture. Reconstitute with bacteriostatic water; stable at 2-8°C for 30 days. The structural modifications provide significant proteolytic resistance.