CJC-1295

What it is — and why the DAC distinction matters

CJC-1295 is a synthetic analogue of human growth-hormone-releasing hormone (GHRH). It is based on a truncated, biologically active form — hGRF(1-29) — with four amino acid substitutions that resist proteolytic degradation. ConjuChem extended its half-life further by attaching a maleimidopropionic acid linker called the Drug Affinity Complex, or DAC. This group covalently binds to free cysteine-34 on serum albumin after injection, shielding the peptide from clearance. The result is a plasma half-life of approximately 6–8 days and sustained GH and IGF-1 elevation lasting over a week from a single dose — demonstrated in published human trials.

This is the version ConjuChem tested clinically, and it is what all published literature describes. A second version — the same sequence without the DAC linker — is widely sold under the names "CJC-1295 without DAC," "CJC-1295 no DAC," or "Modified GRF 1-29." Without albumin binding, it has a half-life of roughly 30 minutes and is pharmacologically distinct from the ConjuChem compound. Despite sharing a base sequence, these are not equivalent drugs. Much of what circulates in research-chemical markets under "CJC-1295" is the non-DAC version, yet citations offered in support almost always reference the DAC-version trials — a systematic conflation that misleads buyers about what evidence actually exists.

How it works

CJC-1295 (with DAC) binds the GHRH receptor on the surface of pituitary somatotrophs, raising intracellular cAMP and calcium to stimulate GH release. GH then drives hepatic production of IGF-1, the primary downstream mediator of GH's anabolic and metabolic effects. Because the DAC version persists in circulation for days, it produces sustained, multi-day elevation of baseline GH and IGF-1 rather than a single short pulse. Ionescu and Frohman (2006) showed that despite this continuous stimulation, normal pulsatile GH secretion is preserved — pulse frequency and amplitude remain intact, superimposed on a markedly elevated trough — indicating that somatostatin-mediated feedback continues to operate.

The non-DAC version produces a single GH pulse analogous to native GHRH injection (~30-minute half-life) and is often stacked in online protocols with ipamorelin. No published peer-reviewed human pharmacology study exists for the non-DAC version as a stand-alone compound.

What the research shows

The published evidence base for CJC-1295 consists of two key human Phase 1 studies — both using the DAC version — and several preclinical characterisation papers. The human studies established that the drug raises GH and IGF-1 in healthy adults in a dose-dependent way and is well-tolerated over short observation windows. They did not measure body composition, muscle mass, fat loss, recovery, or any clinical outcome.

Safety and limitations

In the published human trials, CJC-1295 with DAC was generally well tolerated at single doses tested in healthy adults. Adverse effects were mild and consistent with the known pharmacology of GH elevation: transient injection-site reactions (redness, pain), water retention, headache, and flushing. No serious adverse events were reported in published Phase 1 data.

However, this reassuring short-term profile must be kept in context. These were single-dose studies in healthy volunteers, observed for one to two weeks. The long-term safety of sustained GH and IGF-1 elevation — what months of self-administration would produce — has never been studied in a controlled human setting. Known risks of chronic GH excess include insulin resistance, peripheral oedema, carpal tunnel syndrome, and, speculatively, effects on proliferating cells in individuals with occult malignancy. These are not theoretical: they are documented effects of therapeutic GH excess and acromegaly.

ConjuChem discontinued development after Phase 2 without publishing a transparent explanation. It is known that a different ConjuChem DAC compound was linked to a death in a separate trial, and the overall pipeline was shelved in the mid-2000s, but the specific decision-making around CJC-1295 has not been disclosed. No Phase 3 trial or regulatory submission was completed. The non-DAC version ("Mod GRF 1-29"), most commonly sold in research-chemical markets, has no published human trial of its own; its safety profile at self-administration doses is entirely uncharacterised.

Claims that CJC-1295 produces meaningful gains in muscle mass, fat loss, improved recovery, or anti-aging benefits in healthy adults have no support from peer-reviewed human RCTs. Published trials measured GH and IGF-1 as pharmacodynamic markers only. Rodent body composition findings have not been replicated in human trials.

Research-chemical preparations sold online are unregulated. Purity, sterility, accurate peptide content, and absence of contaminants cannot be verified. CJC-1295 is not approved as a drug or supplement in any jurisdiction.

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