What Is CJC-1295
CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH), specifically based on the first 29 amino acids of endogenous GHRH — the minimum sequence required for full GHRH receptor activity. It was developed by ConjuChem, a Canadian biotechnology company, to overcome the primary limitation of natural GHRH and earlier analogs: rapid enzymatic degradation in plasma (natural GHRH has a half-life of minutes).
Four amino acid substitutions (D-Ala at position 2, Gln at position 8, Ala at position 15, and Leu at position 27) improve the peptide's resistance to protease degradation. CJC-1295 stimulates growth hormone release by binding to GHRH receptors on somatotroph cells in the anterior pituitary gland.
DAC vs. No-DAC: The Critical Distinction
CJC-1295 with DAC
MW: ~3,647 Da
The Drug Affinity Complex (DAC) is a maleimido-modified lysine residue at position 30 that covalently bonds to albumin in the bloodstream after injection. Since albumin has a plasma half-life of roughly two to three weeks, the attached peptide circulates with it, extending CJC-1295's effective half-life to approximately 6–8 days.
Effect: Sustained, continuous elevation of GH and IGF-1 over several days. Dosed approximately once or twice weekly.
CJC-1295 without DAC (Mod GRF 1-29)
MW: ~3,367 Da
Without the DAC moiety, the peptide has a half-life of approximately 30 minutes. It produces a more natural pulsatile release of growth hormone rather than sustained elevation.
Effect: Short GH pulse mimicking natural physiology. Typically dosed multiple times daily, often combined with a growth hormone-releasing peptide (GHRP) like Ipamorelin.
This distinction is not cosmetic — these are functionally different compounds with different pharmacokinetics. Products labeled “CJC-1295” without specifying DAC status are ambiguous. Mass spectrometry immediately resolves this: ~3,647 Da = DAC version, ~3,367 Da = no-DAC.
Mechanism of Action
GHRH Receptor Activation
CJC-1295 binds to GHRH receptors on pituitary somatotroph cells, stimulating the release of growth hormone. This mimics the action of endogenous GHRH but with greater metabolic stability.
GH and IGF-1 Elevation
Released GH stimulates hepatic production of insulin-like growth factor 1 (IGF-1), which mediates many of the downstream effects on tissue growth, repair, and metabolism.
Pulsatile vs. Sustained Release
Normal GH physiology is characterized by discrete high-amplitude pulses, primarily during deep sleep. The no-DAC version preserves this pulsatile pattern. The DAC version produces sustained elevation, which may or may not be physiologically preferable — this remains an area of debate.
Clinical Evidence
This remains the most significant human clinical data for CJC-1295. A subsequent Phase 2 trial in HIV-associated visceral obesity (NCT00267527) was terminated by ConjuChem in 2006 after a participant in Argentina died of an acute myocardial infarction roughly two hours after an eleventh weekly dose; the investigating physician's stated most likely explanation was asymptomatic coronary artery disease with plaque rupture. No Phase 3 trial has been conducted for either version.
Limitations
- Phase 1 data is the only completed human efficacy data for the DAC version. The one Phase 2 trial was terminated early, and no Phase 3 trial has been run for either form.
- Long-term safety data is not available. The effects of sustained GH/IGF-1 elevation over months or years have not been characterized in controlled studies for CJC-1295.
- Sustained GH elevation (DAC version) is not physiological. The body releases GH in pulses for a reason. Whether continuous elevation carries risks beyond those of pulsatile release is an open question.
- CJC-1295 is a WADA-prohibited substance, named explicitly in section S2.2.4 (growth hormone releasing factors) of the Prohibited List alongside sermorelin and tesamorelin. It is prohibited at all times, in and out of competition, and the list covers GHRH analogues generally, so the no-DAC version is included too.
- CJC-1295 is not FDA-approved for any medical use in either form.
Purity and Lab Testing
Mass Spectrometry — Essential
Mass spec is critical for CJC-1295 because it distinguishes the two versions:
- ~3,647 Da = CJC-1295 with DAC
- ~3,367 Da = CJC-1295 without DAC (Mod GRF 1-29)
Because both share a similar core sequence, a product label alone does not establish DAC status. A COA without mass spec leaves it ambiguous.
HPLC Purity
Research-grade CJC-1295 (either version) should test at 95% or above via HPLC. At 29 amino acids, synthesis complexity is moderate.
For a complete guide to evaluating COAs, see How to Read a Peptide COA.
Summary
CJC-1295 is a synthetic GHRH analog available in two functionally different forms: with DAC (~3,647 Da, sustained GH elevation, weekly dosing) and without DAC (~3,367 Da, pulsatile GH release, multiple daily doses). The DAC version has Phase 1 human data showing dose-dependent GH and IGF-1 elevation lasting 9–11 days. Neither version is FDA-approved. Mass spectrometry is essential to confirm which version a product contains.