What Is CJC-1295?
CJC-1295 is a synthetic analogue of Growth Hormone-Releasing Hormone (GHRH), engineered for extended biological half-life compared to native GHRH. The compound is a 30-amino acid peptide based on GHRH(1–29), the biologically active fragment of the full 44-amino acid endogenous GHRH molecule. CJC-1295 incorporates four amino acid substitutions relative to GHRH(1–29) that improve resistance to enzymatic degradation, particularly by serum dipeptidyl peptidase IV (DPP-IV).
CJC-1295 is most commonly encountered in two variants in the research literature: CJC-1295 with DAC (Drug Affinity Complex) and CJC-1295 without DAC (also known as Modified GRF 1-29 or Mod-GRF). The DAC modification, a lysine-reactive bioconjugation element, allows the peptide to reversibly bind to serum albumin, dramatically extending its circulating half-life from minutes to days. The non-DAC version follows a pharmacokinetic profile more similar to native GHRH fragments.
CJC-1295 is not approved for human use by Health Canada or any major Western regulatory body. In Canada, it is classified as a research compound and is sold exclusively for in-vitro and laboratory research purposes. This overview provides an educational research context for investigators studying GH-axis peptide pharmacology.
Chemical Profile and Structure
CJC-1295 is based on the first 29 amino acids of human GHRH, with specific amino acid substitutions that confer improved stability.
Key Chemical Characteristics
- Type: Synthetic GHRH analogue (29 amino acids + modifications)
- Base Sequence: GHRH(1–29) with 4 amino acid substitutions
- Molecular Weight (with DAC): ~3647.3 Da
- Molecular Weight (without DAC): ~3367.9 Da
- CAS Number (with DAC): 863288-34-0
- Physical Form: Lyophilized white powder
- Solubility: Soluble in sterile water and aqueous buffers
Amino Acid Substitutions in CJC-1295
The four key amino acid substitutions in CJC-1295 relative to native GHRH(1–29) are:
- Ala→Aib (position 2): Improves DPP-IV resistance
- Gln→Ala (position 8): Stability improvement
- Ala→Gln (position 15): Stability improvement
- Leu→Lys (position 27): Provides DAC conjugation site (in the DAC version)
CJC-1295 With DAC vs Without DAC
One of the most important distinctions in CJC-1295 research is the difference between the DAC and non-DAC variants. These are distinct compounds with meaningfully different pharmacokinetic profiles:
| Feature | CJC-1295 with DAC | CJC-1295 without DAC (Mod-GRF 1-29) |
|---|---|---|
| Half-life | 6–8 days (albumin-bound) | ~30 minutes |
| GH Release Pattern | Sustained, blunted pulsatility | Pulsatile, physiological-like |
| Albumin Binding | Yes (via DAC maleimide reaction) | No |
| Research Context | Chronic GH elevation models | Physiological GH pulse models |
| Common Research Name | CJC-1295 DAC | Mod-GRF 1-29 or CJC-1295 no DAC |
This distinction matters significantly for research protocol design. The non-DAC version is generally considered more appropriate for research seeking to model physiological GH pulsatility, while the DAC version has been used in research examining sustained GH elevation over extended periods.
Research Background
CJC-1295 was developed as part of ConjuChem’s research program into biologically optimized peptide conjugates. The DAC technology was designed to exploit the body’s natural albumin recycling mechanisms to dramatically extend peptide half-lives without immunogenicity concerns associated with PEGylation and other half-life extension technologies.
Clinical research on CJC-1295 was conducted primarily by ConjuChem in the mid-2000s, demonstrating dose-dependent increases in GH and IGF-1 levels in healthy adult subjects with sustained effects lasting days after single administration. However, CJC-1295 never completed the clinical trial process to achieve regulatory approval, and the development program was discontinued. The compound has since been extensively studied as a research tool for GH-axis investigations.
For comparison with other GHRH-axis compounds, see our article on Tesamorelin, the only GHRH analogue to achieve regulatory approval.
Mechanisms of Interest in Research
CJC-1295’s mechanism of action involves binding to and activating the pituitary GHRH receptor (GHRHR), triggering growth hormone synthesis and secretion. Several aspects of this mechanism are of interest to researchers:
GHRH Receptor Activation
Like endogenous GHRH, CJC-1295 binds to GHRHR on pituitary somatotroph cells, activating adenylyl cyclase and increasing intracellular cAMP, which drives GH synthesis and secretion. The DAC version’s albumin binding creates a slow-release depot effect.
GH and IGF-1 Response
Published clinical research on CJC-1295 DAC documented mean GH increases of 2–10 fold above baseline and IGF-1 increases of 1.5–3 fold above baseline, sustained over days following administration. These findings were from early-phase human research studies and represent investigational data only.
Somatostatin Interaction
Because CJC-1295 (particularly the DAC version) maintains elevated GHRH-receptor stimulation over extended periods, it interacts with endogenous somatostatin regulation differently than pulsatile GHRH. This has implications for research into hypothalamic-pituitary axis regulation.
Preclinical Research Overview
The preclinical and published clinical research on CJC-1295 includes:
Phase I Clinical Research (CJC-1295 DAC)
A published Phase I clinical study in healthy adults demonstrated significant, dose-dependent increases in mean GH concentrations and IGF-1 levels lasting multiple days after a single administration. These findings validated the pharmacokinetic concept of the DAC technology but did not establish therapeutic efficacy for any clinical indication.
Animal Model Research
Preclinical animal research has examined the effects of sustained GHRH-receptor stimulation (via CJC-1295 and related analogues) on body composition parameters, organ weights, and IGF-1 dynamics in rodent and non-human primate models.
Research Tool Applications
CJC-1295 has been used as a research tool to study GHRH receptor pharmacology, GH pulse dynamics, and somatotroph physiology in controlled experimental settings.
For further reading on GH-axis research peptides, see our articles on Ipamorelin and the CJC-1295 vs Ipamorelin comparison. For broader context on research peptides, see research peptides explained.
CJC-1295 in the GHRH Research Context
CJC-1295 occupies a distinct position in the GH-axis research landscape due to its combination of GHRH-receptor specificity and dramatically extended half-life via DAC technology. It is frequently studied alongside Ipamorelin — a growth hormone secretagogue acting via the ghrelin receptor rather than GHRHR — because combining GHRH-pathway and ghrelin-pathway stimulation in animal models produces synergistic GH responses.
Researchers interested in GH-axis modulation often examine these compounds in combination protocols within approved research frameworks. The mechanistic rationale is that GHRH (stimulating somatotrophs) and ghrelin-mimetics (amplifying GH pulse amplitude and reducing somatostatin tone) operate through complementary pathways.
For compliance context on research compounds in Canada, see research compound safety and compliance.
Storage and Handling
Recommended Storage Conditions
- Long-term (lyophilized): −20°C or below
- Short-term (lyophilized): 2–8°C for up to several weeks
- Post-reconstitution: 2–8°C; use within protocol-specified timeframe
- Avoid: Repeated freeze-thaw cycles, direct light, humidity, elevated temperatures
See our peptide storage guide and peptide reconstitution guide for detailed protocols.
Purity and Testing Standards
- HPLC Purity: ≥98% for research-grade compounds
- Mass Spectrometry: Confirms correct molecular identity and presence/absence of DAC modification
- CoA: Mandatory for verifying purity and identity before research use
See what is a Certificate of Analysis? and how TrueCanPeptides tests compounds.
Related Research Compounds
- Ipamorelin: GH secretagogue via ghrelin receptor — complementary to CJC-1295 in GH-axis research
- Tesamorelin: Full-length GHRH analogue with regulatory approval for specific indication
- Longevity Research Peptides: Overview of peptides investigated in aging and longevity research
- Metabolic Research Peptides: Overview of peptides studied in metabolic research contexts
Frequently Asked Questions
Q: What is CJC-1295?
CJC-1295 is a synthetic GHRH analogue based on GHRH(1–29) with four stabilizing substitutions. Available as CJC-1295 with DAC (6–8 day half-life) and without DAC (Mod-GRF, ~30 min half-life). Not approved for human use in Canada — research compound only.
Q: What is the difference between CJC-1295 with DAC and without DAC?
With DAC: albumin-binding modification, 6–8 day half-life, sustained GH elevation. Without DAC (Mod-GRF 1-29): ~30 min half-life, pulsatile GH release pattern. These are distinct compounds for different research applications.
Q: Is CJC-1295 approved for use in Canada?
No. Not approved by Health Canada. Classified as a research compound for in-vitro and laboratory research only.
Q: How does CJC-1295 work mechanistically?
Binds and activates the GHRH receptor (GHRHR) on pituitary somatotrophs, triggering cAMP-mediated GH synthesis and secretion. DAC variant’s albumin binding creates a sustained slow-release pharmacokinetic profile.
Q: Why is CJC-1295 often studied alongside Ipamorelin?
Complementary mechanisms: CJC-1295 activates GHRHR to drive GH synthesis; Ipamorelin acts via the ghrelin receptor to amplify GH pulse amplitude. Animal research documents synergistic GH responses. See CJC-1295 vs Ipamorelin comparison.
Related Articles
- What Is Ipamorelin? Research Overview
- CJC-1295 vs Ipamorelin: Research Comparison
- What Is Tesamorelin? Research Overview
- Tesamorelin vs HGH: Research Comparison
- Peptides for Metabolic Research
- Research Peptides Explained
Disclaimer: All compounds discussed on this page are intended strictly for laboratory and research purposes. They are not approved for human use, are not intended to diagnose, treat, cure, or prevent any disease or condition, and should not be used outside of a controlled research environment. TrueCanPeptides does not provide medical advice. Consult a qualified healthcare professional before making any health-related decisions. Research compounds are sold for in-vitro and laboratory use only.