CJC-1295 With DAC vs Without DAC

CJC-1295 shows up online in two forms - "with DAC" and "without DAC" (sometimes called Mod GRF 1-29) - and the two get confused constantly, since they're often just called "CJC-1295" without specifying which one. They're built from the same core sequence, but one small addition changes how long the peptide sticks around in the body, from hours to days.

What DAC actually is

DAC stands for Drug Affinity Complex. It's a small chemical linker attached to the end of the peptide that lets it grab onto albumin, a protein that's constantly circulating in blood. Once attached to albumin, the peptide effectively hitches a ride and stays in circulation for much longer than it would on its own.

The two versions, side by side

• CJC-1295 without DAC (Mod GRF 1-29): clears the body within roughly 30 minutes to a few hours
• CJC-1295 with DAC: remains active in the body for several days, thanks to the albumin-binding tag
• Both versions target the same receptor and trigger the same signalling pathway - the difference is purely how long that signal lasts

Why that timing difference matters for research

Both versions activate the GHRH receptor - the same one your body's natural growth-hormone-releasing hormone uses - which triggers a pulse of growth hormone release. The no-DAC version gives researchers a short, sharp signal that mimics the body's natural pulsing pattern, which is useful for studying acute, short-window responses. The DAC version instead gives a long, steady signal, which is more useful for research questions about sustained receptor activation over days rather than minutes. Neither is simply "better" - they're suited to different research questions.

What the research shows so far

Studies on CJC-1295 with DAC have shown it can sustain elevated growth hormone and IGF-1 levels for an extended period after a single administration, which is the whole point of the albumin-binding design. Research on the no-DAC version tends to focus on pulsatile signalling patterns - how the body responds to a short, sharp hormone spike rather than a sustained elevation. Comparative studies looking at both side by side are still relatively limited, so most of what's known comes from studying each version independently.

What we still don't know

It's not fully settled which signalling pattern - short pulses or sustained elevation - more closely mirrors natural physiology, and that's a genuinely open research question rather than a solved one. Long-term effects of repeated DAC administration on receptor sensitivity over extended timelines are also still being studied.

Compliance reminder

CJC-1295 with DAC is supplied for in vitro laboratory research purposes only. It is not listed on the Australian Register of Therapeutic Goods (ARTG) and is not intended for human or animal consumption.

Researching GHRH receptor pharmacology? View CJC-1295 with DAC - HPLC tested, COA included.