CJC-1295 without DAC, more precisely called Modified GRF (1-29) or tetrasubstituted GRF 1-29, is one of the most commonly referenced GHRH analogs in endocrine research. It is a stabilized version of the first 29 amino acids of growth hormone-releasing hormone, which is the minimal fragment that retains full receptor activity. This guide covers the molecule itself; if you are weighing the two CJC-1295 forms, our CJC-1295 DAC vs no DAC comparison covers that question directly.
What Is CJC-1295 no DAC?
Native GHRH is a 44-amino-acid hormone, but research in the 1980s showed that the N-terminal 1-29 fragment (sermorelin) retains its receptor activity. That fragment is cleaved rapidly by dipeptidyl peptidase-4 (DPP-4) and other enzymes. Modified GRF (1-29) introduces four amino acid substitutions, at positions 2, 8, 15 and 27, to slow that degradation and reduce oxidation and rearrangement in solution.
The result is a 29-residue GHRH analog that keeps the short-acting character of the native fragment while being more robust in experimental systems. It has no Drug Affinity Complex, the lysine-linked maleimide group used in the DAC version to bind albumin.
The Significance of the Four Substitutions
- D-Ala2: blocks DPP-4 cleavage at the N-terminus, the main inactivation route for native GRF.
- Gln8: replaces asparagine to reduce deamidation and rearrangement.
- Ala15: replaces glycine, reported to improve receptor binding.
- Leu27: replaces methionine to prevent oxidation.
For chemists, these changes are a clean case study in rational peptide stabilization, and they make Mod GRF 1-29 a useful example for any lab studying degradation pathways.
Common Laboratory Research Themes
- Pulsatile signaling models: because it lacks DAC, it is used where a short signaling window is preferred over sustained receptor exposure.
- GHRH-receptor pharmacology: cAMP signaling assays in pituitary cell models.
- Dual-pathway studies: pairing GHRH-receptor agonism with GHS-R1a agonists such as Ipamorelin.
- Stability research: comparing native GRF 1-29 and modified sequences under enzymatic challenge.
These are preclinical research themes and do not indicate any effect in people.
Specifications at a Glance
- Class: GHRH analog
- Length: 29 amino acids, C-terminal amide
- Target: GHRH receptor
- DAC: none
- Form: lyophilized powder
- Size: 10mg vial
- Verification: HPLC purity and MS identity, third-party tested
Quality Documentation
Because Mod GRF 1-29 differs from sermorelin by only four residues, mass spectrometry is the key identity check: the observed mass should match the substituted sequence, not the native one. Mislabeling between GHRH analogs is a known sourcing issue, which is why COAs should list the molecular weight explicitly. See reading a spec sheet and mass spectrum and what third-party testing actually proves. Genetic Peptides USA lots are PepAssure third-party verified.
Storage and Stability
Supplied lyophilized, it is best kept cold, dry and away from light. Even with stabilizing substitutions, peptides in solution degrade faster than freeze-dried material; peptide degradation pathways explains the chemistry behind this.
Where to Go Next
See the CJC-1295 no DAC 10mg research peptide page, the CJC-1295 + Ipamorelin blend, or the GH-Axis Research collection. Related guides: Sermorelin overview and Ipamorelin overview.
Frequently Asked Questions
What is Modified GRF 1-29?
It is another name for CJC-1295 without DAC: a 29-amino-acid GHRH analog with four substitutions that improve stability over native GRF 1-29.
Which positions are substituted?
Positions 2 (D-Ala), 8 (Gln), 15 (Ala) and 27 (Leu), which reduce DPP-4 cleavage, deamidation and oxidation.
How does it differ from sermorelin?
Sermorelin is the unmodified GRF 1-29 fragment; Modified GRF 1-29 carries four substitutions, so the two have different molecular masses.
Why do researchers use the no-DAC form?
It retains a short signaling window, which suits pulsatile GHRH-receptor models rather than sustained exposure studies.
Is CJC-1295 no DAC for human use?
No. It is sold for laboratory research use only, not for human or veterinary use, and is not intended to diagnose, treat, cure, or prevent any disease.
All products referenced in this article are sold strictly for laboratory research use only. They are not for human or veterinary use, are not drugs, foods, or cosmetics, and are not intended to diagnose, treat, cure, or prevent any disease. Nothing here is guidance on administration or handling outside a qualified laboratory setting.