CJC-1295 (without DAC)

DAC vs No DAC: Critical Distinction

CJC-1295 is sold in two forms that have fundamentally different pharmacological profiles:

CJC-1295 with DAC (Drug Affinity Complex): Extended half-life of 6-8 days due to albumin-binding modification. Produces sustained GH elevation for the entire week. Used in some clinical protocols but considered less suitable for biohacking due to continuous GH elevation rather than physiological pulsatile release.

CJC-1295 without DAC (also called Mod GRF 1-29): Half-life of 30 minutes, producing a discrete GH pulse. This mimics the physiological pattern of endogenous GHRH release. This is the preferred form for most biohacking and anti-ageing protocols because it amplifies natural GH pulses without disrupting the pulsatile rhythm that GH-sensitive tissues depend on.

When researchers and practitioners refer to the standard Ipamorelin/CJC-1295 stack, they almost always mean the no DAC form.

Mechanism of Action

CJC-1295 (no DAC) is a 29-amino acid analogue of endogenous GHRH with modifications that extend its stability compared to natural GHRH (which has a half-life of only 2 minutes). It binds to GHRH receptors on pituitary somatotroph cells, activating the cAMP/PKA signalling pathway that drives GH synthesis and secretion.

Critically, CJC-1295 does not directly release GH - it primes the somatotrophs to release more GH when the release trigger (GHSR activation by Ipamorelin or natural ghrelin) arrives. This is why combining it with Ipamorelin produces synergistic amplification: CJC-1295 loads the somatotrophs with GH; Ipamorelin fires the release trigger.

Why Fasted Injection Matters

Glucose and insulin are potent inhibitors of GHRH-stimulated GH release. Studies have shown that post-meal insulin elevation can reduce GH secretion by up to 70% in response to GHRH stimulation. This is why CJC-1295 must always be injected in a fasted state - ideally at least 2-3 hours after the last meal and 30-60 minutes before sleep (when natural GH pulsatility is highest).