CJC-1295 (No-DAC)Growth Hormone

Overview

CJC-1295 (No-DAC) — better known as Modified GRF 1-29 (mod GRF 1-29) — is the short-acting form of the CJC-1295 GHRH analog. It is the tetrasubstituted [D-Ala2, Gln8, Ala15, Leu27] version of growth-hormone-releasing hormone's first 29 amino acids, without the albumin-binding Drug Affinity Complex (DAC) that defines the long-acting CJC-1295 DAC version. The four substitutions protect it from enzymatic breakdown, giving a half-life of ~30 minutes versus under 10 minutes for native GRF(1-29) — but it is still short-acting, producing only a brief GH pulse. It is research-use-only and not FDA-approved.

Mechanism

Mod GRF 1-29 binds the GHRH receptor on pituitary somatotrophs and stimulates a pulsatile release of the body's own growth hormone, which raises hepatic IGF-1. Because it lacks the DAC albumin-binding tail, the peptide is cleared within roughly 30 minutes, so each dose produces a single short GH pulse that mimics natural GHRH pulsatility. This is why it is typically dosed several times per day and usually combined with a ghrelin-receptor agonist (a GHRP such as ipamorelin) for a synergistic pulse — in contrast to the steady, multi-day GH/IGF-1 elevation of the DAC form.

Clinical evidence

There are no dedicated controlled human trials of the no-DAC form. The early-phase human pharmacokinetic studies usually attributed to "CJC-1295" actually used the DAC version; they established the tetrasubstituted GRF(1-29) backbone but not this short-acting peptide's clinical effects. Evidence for mod GRF 1-29 specifically is limited to its known GHRH-agonist pharmacology and anecdotal use; no trial demonstrates a body-composition, performance, or anti-aging outcome.

Safety profile

Human safety data are sparse and short-term. Commonly reported effects are injection-site reactions, transient flushing/head-rush, and water retention or tingling; as a GH secretagogue it can raise GH/IGF-1 and may affect glucose metabolism with frequent use. There are no long-term or large-population safety data, and research-grade material is of unverified purity. It is prohibited in sport (WADA S2) and not FDA-approved. Research use only — nothing here is therapeutic or dosing guidance.

Compare

• vs CJC-1295 DAC

  The long-acting albumin-binding version of the same peptide; days-long GH/IGF-1 elevation vs this short pulse.

• vs Ipamorelin

  A GHRP commonly paired with this GHRH analog for a synergistic GH pulse.

• vs Sermorelin

  Native unmodified GHRH(1-29); shorter-lived and the basis molecule this is derived from.