What Is CJC-1295?
CJC-1295 is a synthetic analog of the first 29 amino acids of endogenous GHRH (growth hormone-releasing hormone). Four amino acid substitutions confer resistance to enzymatic degradation, particularly from dipeptidyl peptidase-4 (DPP-4), making it more stable than the native sequence. Native GHRH(1-29) has a circulating half-life of approximately 7 minutes; the CJC-1295 modifications extend this substantially before the DAC modification is even applied.
The DAC Modification
The DAC (Drug Affinity Complex) addition attaches a maleimido-propionic acid moiety to the peptide, creating a reactive site that forms a covalent bond with serum albumin's cysteine-34 residue upon entering circulation. Since albumin has a half-life of approximately 19 days in vivo, the CJC-1295 DAC–albumin complex persists dramatically longer than free peptide. The covalent bond is stable enough to sustain activity throughout the albumin molecule's natural lifecycle.
Half-Life Comparison
| Variant | Half-life | Signaling Pattern |
|---|---|---|
| Native GHRH(1-29) | ~7 minutes | Very brief; requires frequent pulsatile dosing |
| CJC-1295 (no DAC) | ~30 minutes | Pulsatile — approximates natural GH rhythm |
| CJC-1295 DAC | ~6–8 days | Sustained — continuous GHRH receptor stimulation |
The approximately 300-fold half-life difference between the no-DAC and DAC variants fundamentally alters the GH secretion profile and, therefore, the scientific questions each variant can address.
Physiological Context: GH Pulsatility
Endogenous GH secretion is pulsatile — characterized by discrete peaks (primarily during slow-wave sleep) followed by troughs with very low circulating GH. This pulsatile pattern is essential for normal anabolic signaling, tissue responsiveness, and IGF-1 generation. The pituitary somatotrophs release GH in response to hypothalamic GHRH pulses and are subject to somatostatin-mediated inhibition between pulses.
- CJC-1295 (no DAC) — by mimicking the brief GHRH pulse, preserves somatotroph rhythm and GH pulsatility architecture. Research designs studying natural GH axis dynamics, circadian secretion patterns, or neuroendocrine feedback benefit from this variant.
- CJC-1295 DAC — by providing sustained GHRH receptor stimulation, produces continuous GH elevation. This blunts pulsatility and creates a pharmacological state distinct from normal physiology. Research studying chronic GH elevation, steady-state IGF-1 kinetics, or tissue-level effects of sustained (vs. pulsatile) GH activity benefit from this variant.
Research Selection Guide
Non-DAC (CJC-1295 without DAC): - Investigators studying natural GH pulsatility and its downstream effects - Circadian rhythm and sleep architecture research - Neuroendocrine feedback mechanism studies - Protocols requiring discrete, time-controlled GHRH stimulus events - Studies where trough-to-peak GH dynamics are relevant outcome measures
DAC (CJC-1295 with DAC): - Studies examining chronic GH elevation effects on tissue metabolism - IGF-1 kinetics under sustained GHRH drive - Simplified once-weekly dosing protocols for multi-week study designs - Comparative studies against native somatotropin or IGF-1 direct administration - Body composition and anabolic tissue studies where sustained GH exposure is the experimental variable
Related GHRH Analogs
| Compound | Half-life | Key Feature |
|---|---|---|
| Sermorelin | ~10–20 min | Shortest-acting GHRH analog; closest to native GHRH(1-29) pattern |
| Tesamorelin | ~30–40 min | FDA-approved for HIV-associated lipodystrophy; moderate duration |
| CJC-1295 (no DAC) | ~30 min | DPP-4 resistant; similar duration to tesamorelin |
| CJC-1295 DAC | ~6–8 days | Albumin-binding; longest-acting GHRH analog in research use |
| MOD GRF(1-29) | ~30 min | Alternative name for CJC-1295 no DAC; same compound |
Note: CJC-1295 without DAC is also marketed as "Modified GRF(1-29)" or "Mod GRF 1-29." These names refer to the same molecular entity.
Canadian Regulatory Status
CJC-1295 (both variants) is not approved by Health Canada for human or veterinary therapeutic use. It is available as a research chemical for qualified in vitro and preclinical laboratory investigation. GHRH and its analogs are not currently scheduled as controlled substances under the Controlled Drugs and Substances Act in Canada, and the compounds do not require a special license to purchase for research purposes.
Researchers should be aware that CJC-1295 DAC appears on the World Anti-Doping Agency (WADA) Prohibited List as a growth hormone secretagogue, which has implications for research participants in competitive sports contexts — a consideration for clinical research designs, not standard in vitro laboratory work.
Storage and Handling
Lyophilized CJC-1295 (both variants) should be stored at −20°C for long-term stability. Reconstituted solutions: stable for 28–30 days at 2–8°C (see the full peptide storage guide). The DAC modification does not materially alter storage requirements relative to standard peptide handling practices.
Quality Verification
When sourcing CJC-1295 DAC, explicitly confirm which variant (DAC or no DAC) is specified in the COA, as both share similar names and the DAC modification is not always visible through standard purity testing. Mass spectrometry confirmation is the definitive method: CJC-1295 no DAC has a molecular weight of approximately 3367 Da; CJC-1295 DAC has a molecular weight of approximately 3647 Da. The ~280 Da difference corresponds to the DAC modification mass.
Frequently Asked Questions
What is the difference between CJC-1295 with DAC and without DAC? The DAC (Drug Affinity Complex) modification adds a moiety that covalently bonds to serum albumin, extending the half-life from about 30 minutes (no DAC) to roughly 6–8 days (DAC) — an approximately 300-fold difference. No-DAC preserves pulsatile GH signaling, while DAC provides sustained GHRH receptor stimulation.
How do I confirm which CJC-1295 variant I received? Because both variants share similar names and the DAC modification is not always visible through standard purity testing, mass spectrometry is the definitive method. CJC-1295 without DAC has a molecular weight of approximately 3367 Da; CJC-1295 DAC is approximately 3647 Da. The ~280 Da difference corresponds to the DAC modification mass.
Is CJC-1295 without DAC the same as Modified GRF(1-29)? Yes. CJC-1295 without DAC is also marketed as "Modified GRF(1-29)" or "Mod GRF 1-29." These names refer to the same molecular entity, with a half-life of roughly 30 minutes that approximates the natural pulsatile GH rhythm.
Is CJC-1295 a controlled substance in Canada? No. GHRH and its analogs, including both CJC-1295 variants, are not currently scheduled under the Controlled Drugs and Substances Act and do not require a special license to purchase for research. Note that CJC-1295 DAC appears on the WADA Prohibited List as a growth hormone secretagogue.
Research Disclaimer
CJC-1295 variants are not approved by Health Canada or any regulatory authority for human or veterinary therapeutic use. All applications described are exclusively in vitro or preclinical research contexts. This content is for informational purposes only.