Encyclopedia

CJC-1295 (no DAC), also called Modified GRF (1-29), is a synthetic analog of growth-hormone-releasing hormone (GHRH). It binds the GHRH receptor on the pituitary to stimulate pulsatile GH and IGF-1 release. The 'no DAC' form is short-acting (~30 minutes), which preserves natural pulsatility, in contrast to CJC-1295 with DAC (half-life of several days). It is not FDA-approved and is prohibited in sport.

Native GHRH(1-29) is sermorelin. Modified GRF (1-29) introduces four amino-acid substitutions (positions 2, 8, 15, 27) to resist enzymatic degradation, extending half-life from a few minutes to at least ~30 minutes while keeping the short-acting, pulsatile profile. This is distinct from CJC-1295 'with DAC,' where a Drug Affinity Complex binds albumin to extend half-life to roughly 6-8 days for once-weekly dosing. The no-DAC form is favored in non-clinical use for being more physiologic and easier to titrate, and is commonly paired with a selective GHS such as ipamorelin. It has no approved human therapeutic indication.

Mechanism of Action

Binds the GHRH receptor (GHRHR) on pituitary somatotrophs, activating adenylate cyclase and raising intracellular cAMP, which stimulates synthesis and pulsatile release of growth hormone and downstream IGF-1. The four substitutions confer resistance to dipeptidyl peptidase cleavage.