What Is CJC-1295 No DAC?
CJC-1295 No DAC — also referred to as MOD GRF 1-29 or Modified GRF(1-29) — is a 29-amino acid synthetic analogue of growth hormone-releasing hormone (GHRH). The “No DAC” designation distinguishes it from CJC-1295 with DAC (Drug Affinity Complex), which incorporates a lysine-maleimide conjugate that binds albumin to extend half-life. The No DAC version retains a shorter, more physiological action profile that makes it a preferred tool compound for studying pulsatile growth hormone secretion.
Molecular Structure and Properties
- Also known as: MOD GRF 1-29, Modified GRF(1-29)
- Amino acids: 29 (corresponding to the active N-terminal fragment of native GHRH)
- Molecular weight: ~3,367 Da
- Key modifications vs. native GHRH(1-29): Four amino acid substitutions (positions 2, 8, 15, 27) to improve metabolic stability
- Half-life: ~30 minutes (vs. minutes for native GHRH), enabling pulsatile GH research models
- Receptor target: GHRH receptor (GHRHR) on pituitary somatotrophs
- Supplied as: lyophilised powder for in vitro research use
Mechanism of Action: GHRHR Agonism
CJC-1295 No DAC acts as an agonist at the growth hormone-releasing hormone receptor (GHRHR), a Gs-coupled GPCR expressed predominantly on anterior pituitary somatotrophs. The receptor activation cascade proceeds as follows:
- Gs activation: GHRHR coupling to Gs stimulates adenylyl cyclase, increasing intracellular cyclic AMP (cAMP)
- PKA activation: Elevated cAMP activates protein kinase A, which phosphorylates CREB (cAMP response element-binding protein) and other transcription factors
- GH gene transcription: CREB activation drives transcription of the GH1 gene, increasing cellular GH synthesis
- GH secretion: PKA-mediated phosphorylation promotes GH secretory granule exocytosis — cAMP also activates L-type calcium channels, augmenting calcium-dependent vesicle release
This dual effect on GH synthesis and release distinguishes GHRH receptor agonism from GHSR-1a agonism (Ipamorelin’s target), which primarily stimulates secretion without directly upregulating GH gene expression.
Pulsatile vs. Continuous GH Secretion
CJC-1295 No DAC’s ~30-minute half-life preserves the pulsatile character of GH secretion — the physiological pattern in which GH is released in discrete bursts rather than continuously. This is an important research consideration: continuous GH elevation (as achieved with CJC-1295 with DAC or recombinant hGH) produces different downstream IGF-1 and metabolic responses than pulsatile secretion.
For studies requiring pulsatile GH physiology — including research on somatotroph desensitisation, GH receptor downregulation, and the differential downstream effects of pulse amplitude versus frequency — CJC-1295 No DAC is the appropriate research tool.
Synergistic Research with Ipamorelin
CJC-1295 No DAC (GHRHR agonist) and Ipamorelin (GHSR-1a agonist) activate two distinct receptor pathways in the GH secretion axis. Preclinical research has consistently demonstrated that co-stimulation of both receptors produces synergistic GH release substantially exceeding that of either compound alone — a finding analogous to the physiological co-regulation of GH secretion by GHRH and ghrelin.
This synergistic profile makes the combination a standard approach in GH axis research, reflected in R&D Peptides’ Ipamorelin 10mg / CJC-1295 No DAC 5mg Combination Pen for researchers requiring both pathways in a single compound.
Key Research Areas
GH axis pharmacology: CJC-1295 No DAC is a primary tool compound for GHRHR receptor pharmacology, somatotroph signal transduction, and GH pulse characterisation studies.
IGF-1 axis research: GH release stimulated by GHRHR agonism drives hepatic IGF-1 synthesis. CJC-1295 No DAC is used in models studying the GH-IGF-1 axis, including liver biology, bone metabolism, and anabolic signalling research.
Somatotroph biology: Research examining receptor desensitisation, feedback regulation (somatostatin, GH itself), and somatotroph development uses CJC-1295 No DAC as a controlled GHRHR stimulant.
Metabolic and body composition research: GH’s effects on lipolysis, glucose metabolism, and lean mass are studied using CJC-1295 No DAC in metabolic preclinical models.
Sourcing CJC-1295 No DAC for Research
R&D Peptides supplies CJC-1295 No DAC 10mg as a lyophilised research compound with a batch-specific Certificate of Analysis. Supplied strictly for in vitro research use only.
For quality and testing standards, see our quality and testing page.
All content on this page is for educational and informational purposes only. CJC-1295 No DAC is supplied by R&D Peptides strictly for in vitro research use. It is not intended for human or veterinary administration, and no therapeutic claims are made or implied.
