CJC-1295 With and Without DAC: What the Modification Changes
CJC-1295 is sold and studied in two forms that are frequently conflated. The difference is a single chemical addition, but it changes the compound’s pharmacokinetic profile enough that the two should be treated as separate research materials.
The parent sequence
Both forms are built on a modified fragment of growth hormone-releasing hormone — specifically GHRH(1-29), the shortest fragment that retains full receptor activity. Native GHRH(1-29) is degraded rapidly, with dipeptidyl peptidase-4 cleaving between residues 2 and 3. CJC-1295 carries four amino acid substitutions that resist that cleavage and reduce other degradation routes.
What DAC adds
DAC stands for Drug Affinity Complex: a maleimidoproprionic acid group attached at the C-terminus. That group reacts with a free cysteine thiol on circulating serum albumin, forming a covalent conjugate. The peptide is then carried by albumin, a protein with a multi-day circulating half-life, rather than clearing on its own timescale.
The practical consequence is a large difference in duration of exposure between the two forms. Without DAC, the modified GHRH fragment retains the substitutions that resist enzymatic degradation but has no albumin-binding anchor, so exposure is comparatively brief. This is why the no-DAC form is sometimes referred to in the literature and in supplier catalogues as modified GRF(1-29).
Why the distinction matters experimentally
GHRH receptor signalling is pulsatile in vivo. A short-exposure agonist and a long-exposure agonist therefore probe different questions: one approximates a pulse, the other produces sustained receptor occupancy. Studies comparing pulsatile versus continuous GHRH-receptor stimulation are not interchangeable, and an experimental design written for one form does not transfer to the other.
The published pharmacology of CJC-1295 and of albumin-binding peptide conjugates generally is indexed at PubMed, and the broader albumin-conjugation approach at this search.
Combination with a secretagogue
CJC-1295 is often studied alongside a growth hormone secretagogue receptor agonist such as ipamorelin. The two act on different receptors — GHRHR and GHSR-1a respectively — which is the stated rationale for examining them together in the same model. We stock the no-DAC form and a CJC-1295 and ipamorelin blend, alongside other growth hormone pathway peptides.
Labelling caution
Because both forms share the name CJC-1295, catalogue listings that omit “DAC” or “no DAC” are ambiguous. Confirm which form a certificate of analysis describes before using it to plan an experiment — the molecular weights differ, and a mass spectrometry trace is the clearest way to tell them apart.
ExoLabz supplies compounds for laboratory research use only. Nothing on this page is medical advice or a suggestion of human or veterinary use. Certificates of analysis for each compound are published on this site.
