CJC-1295 (No DAC)

What is CJC-1295 (No DAC)

CJC-1295 without DAC, also referred to in the literature as Mod GRF 1-29, is a synthetic 29-amino-acid analog of human growth-hormone-releasing hormone (GHRH/GRF). The full GHRH molecule is 44 amino acids long, but the 1-29 fragment carries the entire active site, which is why the analog behaves like native GHRH at the receptor.

Compared with the unmodified fragment, the molecule carries four amino-acid substitutions at positions 2, 8, 15, and 27. These raise stability against the degrading enzyme DPP-4 and extend the duration of activity. The defining difference from the long-acting DAC variant: the No-DAC form lacks the Drug Affinity Complex (DAC) group that would otherwise enable covalent binding to albumin. Without that binding the peptide stays short-acting, with a commonly cited half-life of about 30 minutes.

It is not FDA-approved and appears on the FDA Category 2 list. Clinical development of the long-acting DAC variant by ConjuChem reached Phase II and was halted after a participant death. We supply the material as research-grade lyophilized powder.

How it works

CJC-1295 without DAC binds the GHRH receptor on somatotroph cells in the anterior pituitary. Activating that receptor triggers a pulsatile release of growth hormone (GH) into the bloodstream, which in turn drives liver production of IGF-1, the main downstream mediator of GH's effects.

The four substitutions at positions 2, 8, 15, and 27 protect the peptide from rapid degradation by DPP-4 but do not introduce albumin binding. The action therefore stays short: the commonly cited half-life of about 30 minutes is a secondary value in wide use and was not directly measured in the primary studies cited below. As a result, the GH release resembles the body's own pulses rather than producing a sustained elevated level, the way the long-acting DAC variant does with its 6 to 8 day half-life.

The available human research rests on the GRF(1-29) scaffold, that is native and agonist GHRH(1-29) analogs, not the exact Mod GRF(1-29) sequence. In a rat model with in-vitro data, a GRF(1-29) bioconjugate with increased DPP-IV stability showed roughly fourfold GH area under the curve over two hours versus unmodified hGRF(1-29). In an acute human study, GHRH(1-29) analogs given subcutaneously produced comparable GH peaks, though the high potency seen in the rat model was not reproduced in man. Longer studies in children with GH deficiency and in children with idiopathic short stature (using native GRF(1-29)) reported increased growth velocity over twelve months.

Often studied alongside

CJC-1295 without DAC is most often paired in research protocols with a growth-hormone secretagogue that works on a different receptor. Ipamorelin is the cleanest pairing: it acts on the ghrelin/GHS receptor and amplifies the GH pulse without affecting cortisol or prolactin.

Sermorelin is the closely related GHRH(1-29) active fragment without the stabilizing substitutions and is studied in similar GH and IGF-1 contexts.

For reconstitution, the standard solvent in published protocols is bacteriostatic water.

Documentation