CJC-1295 Without DAC Research: GHRH Analogue Molecular Profile | Signal Labs
CJC-1295 (No DAC): Modified GHRH Analogue Research Profile
CJC-1295 without DAC, formally known as Modified GRF 1-29 (Mod GRF 1-29), is a synthetic analogue of the first 29 amino acids of endogenous growth hormone releasing hormone (GHRH). Through four targeted amino acid substitutions it achieves substantially improved metabolic stability compared to native GHRH(1-29) while retaining full GHRH receptor (GHRHR) binding and activation capacity.
Chemical and Molecular Data
| Property | Value |
|---|---|
| Molecular formula | C152H252N44O42 |
| Molecular weight | 3367.9 g/mol |
| CAS number | 863288-34-0 |
| Also known as | Modified GRF 1-29, Mod GRF 1-29 |
| Amino acid count | 29 |
| Purity | greater than or equal to 98% as verified by HPLC |
| Form | Lyophilised powder |
| Storage | -20 degrees C, protected from light and moisture |
| Reconstitution | Bacteriostatic water recommended |
CJC-1295 (No DAC): GHRH Analogue — Pulsatile GH
The Four Stabilising Modifications
Native GHRH(1-29) has a plasma half-life under 10 minutes due to rapid cleavage by dipeptidyl peptidase IV (DPP-IV) at the Ala2 position and various endopeptidases. CJC-1295 (No DAC) addresses these vulnerabilities through four amino acid substitutions.
| Position | Native residue | Modified residue | Rationale |
|---|---|---|---|
| 2 | Ala | D-Ala | Blocks DPP-IV cleavage between positions 1-2 |
| 8 | Asn | Gln | Prevents asparagine deamidation |
| 15 | Gly | Ala | Reduces backbone flexibility, improves stability |
| 27 | Met | Leu | Prevents methionine oxidation |
The resulting peptide retains GHRHR binding and activation equivalent to native GHRH(1-29) in receptor binding assays, with significantly extended half-life, making it a more practical research tool than native GHRH for studies requiring defined receptor stimulation over experimental time frames.
GHRH Receptor Pharmacology
The GHRH receptor (GHRHR) is a class B GPCR expressed predominantly on somatotroph cells of the anterior pituitary gland. Class B GPCRs have a characteristically large extracellular domain that participates in ligand binding, well studied in the glucagon/incretin receptor family (relevant to Retatrutide research). GHRHR activation couples to Gs, raising cAMP and activating PKA, leading to GH gene transcription and GH exocytosis.
Pulsatile GH Secretion Research
A key feature of CJC-1295 (No DAC) as a research tool is its short half-life (approximately 30 minutes) relative to CJC-1295 (With DAC). Single administration produces a discrete GH pulse analogous to physiological GH pulses, which occur approximately every 3-4 hours. Research has examined how GH pulse frequency and amplitude influence IGF-1 production, GH receptor expression, and downstream body composition effects, contrasting with sustained GH profiles.
Combined GH Axis Research
CJC-1295 (No DAC) is frequently studied alongside Ipamorelin, which acts at the complementary GHS-R1a receptor. The GHRHR and GHS-R1a represent distinct but synergistic inputs to pituitary GH release. GHRHR (this compound) mediates cAMP/PKA-driven GH synthesis and release, while GHS-R1a (Ipamorelin) mediates IP3/calcium-driven GH release and additionally suppresses somatostatin inhibitory tone. Using both allows investigation of synergistic dual GH axis stimulation.
Research Applications
CJC-1295 (No DAC) is used in GHRHR binding studies and receptor pharmacology, GH pulse physiology research in animal models, comparative pharmacodynamics with CJC-1295 (With DAC), structure-activity relationship (SAR) studies of GHRH analogues, and GH/IGF-1 axis research.
CJC-1295 Variant Comparison
| Property | Native GHRH(1-29) | CJC-1295 No DAC | CJC-1295 With DAC | Tesamorelin |
|---|---|---|---|---|
| Sequence length | 29aa | 29aa (modified) | 29aa (modified) | 44aa (modified) |
| Key modifications | None | D-Ala2, Gln8, Ala15, Leu27 | Same + MPA linker | trans-3-hexenoic acid |
| DPP-IV resistance | No | Yes | Yes | Yes |
| Albumin binding | No | No | Covalent (Cys-34) | No |
| Plasma half-life | Less than 10 min | ~30 min | ~8 days | ~30 min |
| GH pattern | Pulsatile | Pulsatile | Sustained | Pulsatile |
| CAS | 86168-78-7 | 863288-34-0 | 863288-34-0 | 901758-09-6 |
Frequently Asked Questions
Why are there four amino acid modifications in CJC-1295 (No DAC) rather than just protecting position 2?
The four modifications address different degradation vulnerabilities. Position 2 (Ala to D-Ala) blocks DPP-IV cleavage between positions 1 and 2. Position 8 (Asn to Gln) prevents asparagine deamidation — a chemical instability that occurs at Asn-Gly sequences. Position 15 (Gly to Ala) reduces backbone flexibility and improves conformational stability. Position 27 (Met to Leu) prevents methionine oxidation, which would inactivate the peptide on storage. Together these four changes maximise both enzymatic and chemical stability without altering GHRHR binding affinity.
How does CJC-1295 (No DAC) compare to Sermorelin in research?
Sermorelin is GHRH(1-29) without the four stabilising modifications — essentially native GHRH(1-29) with an amidated C-terminus for slight protection. Its plasma half-life is approximately 10-20 minutes, making it less practical as a research tool for sustained receptor stimulation studies. CJC-1295 (No DAC) retains the same GHRHR pharmacology but with approximately three times the half-life, making it a more tractable research tool without the extreme half-life extension of the DAC version.
Is the pulsatile GH pattern from CJC-1295 (No DAC) truly physiological?
The GH pulses induced by CJC-1295 (No DAC) are pharmacological rather than truly physiological — they are triggered by exogenous peptide administration rather than endogenous GHRH neuronal firing. However, the temporal pattern (a discrete GH pulse followed by return to baseline) resembles physiological pulsatile GH secretion, making it more suitable for studying pulse-dependent GH biology than the sustained elevation produced by CJC-1295 (With DAC). For purely pulsatile GH research, combining CJC-1295 (No DAC) with Ipamorelin allows dual-receptor stimulation in controlled pulse experiments.
Published Research References
For laboratory and analytical research purposes only. Not for human or veterinary use. No dosage or administration guidance is provided or implied.
Related research peptides: CJC-1295 (With DAC) | Ipamorelin | BPC-157 | Retatrutide