# CJC-1295: GHRH Analog, DAC Chemistry, and the Human PK Record > CJC-1295 is a long-acting GHRH analog whose DAC variant binds serum albumin for an estimated 5.8-8.1 day half-life. A cited readout of the chemistry, mechanism, and human studies. A dark readout of the published record: the tetrasubstituted hGRF(1-29) backbone, the albumin bioconjugation that extends duration, and the human pharmacokinetic studies that measured it. Every quantitative claim is cited. ## What the CJC-1295 literature has measured CJC-1295 is a synthetic long-acting analog of growth-hormone-releasing hormone (GHRH), built on the first 29 residues of human GH-releasing factor and engineered to outlast the native peptide by days rather than minutes. In healthy adults, single subcutaneous doses of 30 or 60 micrograms per kilogram produced dose-dependent 2- to 10-fold increases in mean plasma growth hormone for six days or more, and 1.5- to 3-fold increases in IGF-1 for nine to eleven days; after multiple doses, IGF-1 stayed above baseline as long as 28 days [1]. That duration is the whole point of the molecule. The estimated plasma half-life of the long-acting variant was 5.8 to 8.1 days [1] — a figure no unmodified GHRH fragment approaches. It comes from two layers of engineering: four protease-resistant amino-acid substitutions at positions 2, 8, 15, and 27 that block dipeptidylpeptidase-IV cleavage, and a covalent tether to circulating serum albumin. The chemistry is the story this site reads. The molecule has a precise identity. CJC-1295 carries CAS number 863288-34-0 and a peptide molecular weight near 3367.9 daltons before albumin conjugation; after conjugation, the effective circulating species is the much larger peptide-albumin complex of roughly 66 kilodaltons. That structural specificity is why analytical chemists can pin it down: high-resolution LC-MS/MS definitively identified CJC-1295 as the active ingredient in an unknown 'GHRH' pharmaceutical preparation seized in an anti-doping context [6]. CJC-1295 is an unapproved research chemical. It carries no approved human indication anywhere, and the human evidence base is limited to small early-phase pharmacokinetic studies. What follows is an editorial digest of that record — the structure, the mechanism, the dose-response data, and the open gaps — organized as a track-list of the literature. ## CJC-1295 as a GHRH Analog As a [GHRH analog](/), CJC-1295 is a class member alongside sermorelin and the approved drug tesamorelin: all three are synthetic versions of the hypothalamic hormone that tells the pituitary to release growth hormone. The shared scaffold is hGRF(1-29), the N-terminal 29-residue fragment that retains full GH-releasing activity. What separates CJC-1295 from its relatives is how long it survives in plasma. Native GHRH is cleaved within minutes by dipeptidylpeptidase-IV; CJC-1295's four substitutions block that cleavage, and the DAC variant's albumin tether extends residence to a multi-day scale [1] [2]. ## How CJC-1295 Works at the Molecular Level CJC-1295 binds the GHRH receptor — a class B G-protein-coupled receptor — on anterior-pituitary somatotrophs, activating Gs/cAMP/PKA signaling that drives growth-hormone gene transcription and pulsatile GH release, which in turn raises hepatic IGF-1. Cryo-EM structures have since resolved how peptide agonists engage and activate the GHRH receptor, clarifying the receptor conformations these analogs stabilize [7]. The receptor step is the same one native GHRH uses; CJC-1295 simply occupies it for far longer. Because the signaling chain runs receptor to cAMP to GH to IGF-1, the readout researchers measure is downstream: serum GH first, then IGF-1 over the following days. That cascade is the spine of every study summarized here. ## What CJC-1295 Does In published studies, CJC-1295 produces dose-dependent, sustained elevations of growth hormone and IGF-1. In a GHRH-knockout mouse, 2 micrograms given once every 24 hours fully normalized body weight and length and raised pituitary GH mRNA, while dosing every 48 to 72 hours was progressively less effective — direct evidence that the long-acting analog's once-daily schedule is sufficient to restore GH-axis-dependent growth [4]. The albumin-conjugation chemistry was validated earliest in rats: the lead compound showed a 4-fold increase in GH area-under-the-curve over two hours versus the unconjugated peptide, with the albumin conjugate detectable in plasma beyond 72 hours [2]. The pattern that the molecule lengthens exposure and amplifies the GH signal held from the first rodent screen onward. ## What the Research Examines Rather than promising outcomes, the literature examines what stimulating the GH/IGF-1 axis with a long-acting GHRH analog actually does to measurable endpoints. The primary readouts are plasma growth hormone and IGF-1 over time; a proteomic study in 11 healthy young men added candidate biomarkers, finding reproducible serum-protein shifts that correlated linearly with IGF-1 [5]. The honest framing is that these are early measurements, not endorsements. There is no large human efficacy trial and no long-term safety data; a ConjuChem Phase 2 trial in HIV-associated visceral obesity was discontinued and the DAC program did not advance [1]. The interest in CJC-1295 is mechanistic, and that is exactly the register this digest keeps. See [the published human research](/research) for the study-by-study record. ## CJC-1295 as a Research Peptide As a [research peptide](/), CJC-1295 is supplied lyophilized and is handled in laboratory settings — reconstituted with bacteriostatic water and refrigerated. Oral bioavailability is negligible, so the route used in every study is injection. The compound is also a recurring subject of analytical chemistry: high-resolution LC-MS/MS definitively identified CJC-1295 as the active ingredient in an unknown 'GHRH' pharmaceutical preparation seized in an anti-doping context [6], and it is prohibited at all times in sport under WADA Section S2. The two practical distinctions to keep straight are the [CJC-1295 DAC vs no-DAC](/dac-vs-no-dac) forms and the resulting [CJC-1295 half-life](/half-life). --- A near-black readout of the CJC-1295 record — the DAC-vs-no-DAC chemistry and the human PK half-life logged to source and tagged by evidence, with no clinic behind the console and nothing here dispensed or sold.