What does “DAC” mean in peptides like CJC-1295 DAC?

DAC stands for Drug Affinity Complex. It is a modification that lets a peptide bind to albumin in circulation, which dramatically extends how long it stays active.

How it works

The DAC version carries a maleimido-propionic acid linker. Once injected, that linker forms a covalent bond with a free cysteine residue on serum albumin — the most abundant protein in blood plasma. The peptide is then carried by albumin rather than being filtered out by the kidneys, because the bound complex is far too large to clear quickly.

Why the distinction matters

CJC-1295 is sold in two forms, and they behave nothing alike:

• CJC-1295 with DAC — reported half-life measured in days rather than minutes, producing a sustained elevation in signalling.
• CJC-1295 without DAC (often labelled "mod GRF 1-29") — half-life on the order of ~30 minutes, producing a short pulse.

That difference changes everything downstream: how often the compound is administered in a protocol, and whether signalling is pulsatile or continuous. Growth-hormone research cares about that distinction specifically, because the natural pathway is pulsatile.

Two vials labelled "CJC-1295" are therefore not interchangeable. Check which form a listing actually describes before comparing price or protocol — see the CJC-1295 DAC profile. Research use only. Not medical advice.