What is CJC-1295?
CJC-1295 is a synthetic 30-amino-acid analogue of GHRH(1-29), modified to resist enzymatic degradation. Two principal variants exist:
- CJC-1295 without DAC — sometimes called “Modified GRF (1-29)” — produces pulsatile GH stimulation more closely resembling physiological GH release.
- CJC-1295 with DAC — the addition of a maleimidopropionic acid linker that binds covalently to serum albumin, dramatically extending plasma half-life and producing sustained GH elevation.
The DAC variant was originally developed by ConjuChem Biotechnologies and reached Phase II clinical development for growth hormone deficiency indications before being discontinued. The compound is not approved for any human use in the EU, US, or UK.
Evidence snapshot
Status: Preclinical and early clinical (discontinued). Studies referenced: 60+ across both variants. Human RCTs: Limited; DAC program halted. Regulatory approval: None.
Mechanism: GHRH receptor agonism
CJC-1295 binds the GHRH receptor on pituitary somatotrophs, triggering the same intracellular cAMP cascade as endogenous GHRH. The modifications to the peptide backbone extend its half-life by reducing susceptibility to DPP-IV cleavage (the primary degradation pathway for native GHRH).
The DAC variant takes a different route to the same outcome. By binding covalently to circulating albumin, the compound creates a long-lived depot that slowly releases the active peptide. This produces a sustained elevation of GH rather than the pulsatile pattern of native GHRH.
What the research shows
- GH and IGF-1 elevation — single-dose administration of DAC-CJC-1295 produces measurable GH and IGF-1 elevation lasting several days in human Phase I studies.
- Pulsatile vs sustained — non-DAC CJC-1295 produces a more physiological GH pulse; DAC-CJC-1295 produces sustained levels. The two profiles have different downstream consequences for the HPG axis and feedback loops.
- Animal data — rodent studies show dose-dependent GH release with both variants, and chronic administration increases lean mass and reduces fat mass in growth-hormone-deficient models.
Limits and considerations
- Discontinued clinical development — ConjuChem halted the DAC-CJC-1295 program; the reasons are not fully public but include competitive landscape and market dynamics.
- Feedback considerations — sustained GH elevation may downregulate GHRH receptor sensitivity and disrupt pulsatile GH release over time, though this has not been well characterised in humans.
- Off-label combination use — often used in research and off-label contexts with GHS peptides (ipamorelin, GHRP-2) — but combination pharmacology is poorly characterised.
Regulatory status
CJC-1295 (both variants) is not approved for human use in any major jurisdiction. Both are on the FDA peptide watch-list. WADA classifies GHRH analogues and GHS peptides as prohibited in athletic competition.
The bottom line
CJC-1295 is a well-characterised GHRH analogue with consistent preclinical and limited early-clinical data on GH release. The DAC variant offers sustained elevation but disrupts physiological pulsatility. Both forms lack approved human indications. Off-label use is widespread but unsupported by rigorous clinical evidence.