DAC peptide

A DAC peptide carries a Drug Affinity Complex: a maleimide chemical handle that bonds to blood albumin so the peptide lasts days instead of minutes. In CJC-1295, DAC turns a fast-clearing growth-hormone signal into an albumin-bound form with a measured human half-life of roughly six to eight days.

What does DAC mean in peptide names?

DAC means Drug Affinity Complex, not a separate peptide or an ingredient that releases slowly on its own. The DAC used in CJC-1295 is a maleimidopropionamide-lysine unit attached to the peptide’s end. “Chemical grappling hook” is less formal, but easier to remember.

The maleimide reacts with the free sulfur-containing thiol on cysteine 34 (Cys34) of serum albumin, the abundant carrier protein in blood. The original mechanism study demonstrated this albumin attachment and longer persistence in rats. That is strong chemistry and animal pharmacology, not a human treatment-outcome trial.

Why does albumin binding make a peptide last longer?

Albumin binding gives the small peptide a large, long-circulating ride, slowing the rapid clearance that normally cuts many peptide signals short. That matters because enzymes and the kidneys can otherwise remove small peptides quickly. The peptide can remain biologically active while attached; albumin is doing the chauffeuring, not the signaling.

Human evidence confirms the duration for CJC-1295 DAC. In randomized, placebo-controlled studies of healthy adults, researchers estimated a 5.8–8.1-day half-life and measured growth-hormone increases for at least six days after one injection (Teichman et al., 2006). That proves prolonged exposure and hormone effects. It does not prove muscle gain, fat loss, or another downstream benefit; those are different evidence questions covered by our evidence-grading guide.

What is the difference between DAC vs no DAC?

DAC vs no DAC is mainly a chemistry-and-duration distinction, but the names are messy enough to cause real mix-ups. CJC-1295 DAC is the albumin-binding, long-acting compound studied in the human trial. The product commonly called “CJC-1295 no DAC” is the short-acting peptide covered on our Modified GRF 1-29 page.

FDA’s CJC-1295 chemistry review treats the DAC and non-DAC structures separately and warns that inconsistent common names can create identification errors. So “CJC-1295” alone is incomplete: check whether the source means the albumin-binding DAC form or Modified GRF 1-29. One small handle changes the molecule’s timetable from minutes to days.