CJC-1295 without DAC Half-Life & Stability
Part of the full CJC-1295 without DAC guide - a synthetic growth hormone-releasing hormone reference compound, identity-verified with a COA on every vial.
In brief
Pharmacokinetic and stability behavior is where CJC-1295 without DAC most sharply differs from its DAC counterpart, and the entry frames that difference in terms of metabolic stability and receptor-occupancy kinetics rather than any reported numerical half-life in humans. No peptide-specific half-life value is provided in the entry, so this spoke characterizes stability qualitatively from the data that is present: the D-Ala2 substitution's effect on enzymatic clearance, the absence of the albumin-binding extension, and the resulting short receptor-occupancy profile in experimental models. Where claims rest on general peptide-class principles rather than entry-specific figures, that is stated plainly. The throughline is structural: what each engineered feature does, and does not do, to how long the intact agonist persists in laboratory and preclinical systems before degradation or clearance removes it from the GHRH-receptor.
The detail
A closer look
01
D-Ala2 and resistance to DPP-IV clearance
The single most consequential stability feature is the D-Ala2 substitution. Per the Soule, King & Millar (1994) source cited in the entry, incorporating D-Ala2 into GHRH-(1-29)-NH2 confers resistance to dipeptidyl peptidase-IV cleavage and decreases the metabolic clearance rate relative to the unmodified peptide. DPP-IV ordinarily removes the N-terminal dipeptide from native GHRH; by placing a D-amino acid at position 2, the analog resists that proteolysis. The entry frames this as a relative improvement in in-vitro/ex-vivo metabolic stability over the unmodified peptide, not as an absolute half-life figure, so the effect is described directionally: slower enzymatic degradation and reduced clearance, the specific quantitative half-life increase not being given in this entry's data.
02
No albumin binding means short occupancy
The defining kinetic limitation of the no-DAC form is the absence of the Nε-maleimidopropionyl-Lys30 albumin-binding extension. Because it cannot form covalent serum-albumin bioconjugates, the peptide does not gain the circulating depot effect that albumin tethering provides to the DAC variant. The entry states this directly: the no-DAC form exhibits comparatively short receptor-occupancy kinetics in experimental models, in contrast to the long-lasting GRF analog profile that Jette et al. (2005) attribute to the albumin-binding DAC design. So even with DPP-IV resistance protecting the N-terminus, the lack of an albumin anchor keeps the overall persistence and receptor-occupancy window comparatively brief in the cited model systems.
03
Storage stability versus biological stability
It is worth separating two distinct senses of stability. The DPP-IV resistance and reduced metabolic clearance pertain to the peptide's behavior in biological matrices, governing how long it survives enzymatic attack in cell or animal models. Bench storage stability, by contrast, follows general peptide-class handling principles: the lyophilized powder is the most stable state, reconstituted solutions are held cold and aliquoted to avoid freeze-thaw stress, and material is prepared close to use. The entry provides no peptide-specific shelf-life or degradation-rate numbers, so storage stability here is described from general peptide-handling practice rather than from molecule-specific measurements, while the enzymatic-stability claims remain attributed to the Soule et al. (1994) source.
The fine print: products are sold for laboratory research use only and are not for human or animal consumption. Bodily introduction into humans or animals is strictly prohibited by law. CJC-1295 without DAC is not a drug and is not intended to diagnose, treat, cure, or prevent any disease. These statements have not been evaluated by the FDA.