FLIGHT LOG / GHRH ANALOG — DAC & NO-DAC
CJC-1295 is a long-acting GHRH analog whose human telemetry is thin and whose long-acting program was scrubbed.
A mission-log read of the published record: the human pharmacokinetics that were actually measured, the albumin-conjugation engineering that bought a multi-day half-life, and the points where the data simply stop.
The CJC-1295 record, read straight
CJC-1295 is a synthetic, long-acting analog of growth-hormone-releasing hormone (GHRH). A single subcutaneous dose of 30 or 60 ug/kg raised mean plasma growth hormone 2- to 10-fold for six days or more and IGF-1 for nine to eleven days, with an estimated half-life of 5.8-8.1 days in healthy adults [1]. That is the measured envelope. It is a small envelope — a handful of early human pharmacokinetic studies — and everything past it is engineering rationale, animal data, or open question.
The molecule is built on hGRF(1-29), the first 29 residues of human growth-hormone-releasing factor, carrying four amino-acid substitutions (D-Ala at position 2, Gln at 8, Ala at 15, Leu at 27) that block dipeptidylpeptidase-IV cleavage, deamidation, and oxidation [2]. In the DAC variant, a C-terminal linker covalently binds circulating serum albumin, extending the plasma half-life toward that of albumin itself [2]. The no-DAC form — "Modified GRF 1-29" — keeps the four substitutions but lacks the albumin-binding moiety and is short-acting [11].
This site reads that record as a flight log. Each measured datum is logged to its study; each gap is flagged where the data stop. It is editorial commentary on the human and animal research, not guidance for use.
What is CJC-1295?
CJC-1295 is a synthetic long-acting analog of growth-hormone-releasing hormone (GHRH), built on hGRF(1-29) with four protease-resistant substitutions; the DAC variant adds covalent serum-albumin conjugation for a multi-day half-life [2]. It is not a blend and not a hormone replacement — it is a single peptide secretagogue that prompts the pituitary to release the body's own growth hormone.
What does CJC-1295 do?
It binds the GHRH receptor on anterior-pituitary somatotrophs, stimulating synthesis and pulsatile release of growth hormone, which in turn raises hepatic IGF-1 [3]. The four substitutions plus, in the DAC variant, albumin conjugation hold that stimulation in place for days [2]. Notably, the pulsatile pattern of GH secretion persists despite the sustained signal [3].
CJC-1295 as a Research Peptide
As a research peptide, CJC-1295 is a lyophilized GHRH analog handled in laboratory contexts, not an approved medicine. It is unapproved for human use anywhere and is sold by research suppliers for laboratory use [1]. The four-substitution backbone gives it protease resistance; the optional DAC moiety gives the long-acting variant its multi-day duration [2]. The CJC-1295 peptide is, in practice, two distinct pharmacokinetic species — the long-acting DAC form and the short-acting no-DAC "Modified GRF 1-29" — routinely conflated in marketing [11].
Where CJC-1295 Sits Among GHRH Analogs
As a GHRH analog, CJC-1295 belongs to the same class as sermorelin and the FDA-approved tesamorelin — all synthetic versions of the hypothalamic hormone that prompts the pituitary to release growth hormone. A 2025 Nature Reviews Endocrinology review synthesizes the pharmacology of this class, describing receptor signaling and the rationale for long-acting analog design [13]. What separates CJC-1295 within the class is the engineering: the DAC albumin-conjugation that pushes its duration from minutes-to-hours into days [2]. Among GHRH analogs it is the long-acting outlier whose approved-drug program nonetheless did not advance.
How the mechanism reads on the console
The pathway is short and well-mapped. CJC-1295 binds the GHRH receptor — a class B G-protein-coupled receptor on anterior-pituitary somatotrophs — activating Gs/cAMP/PKA signaling that drives GH gene transcription and pulsatile release [3]. Released GH reaches the hepatic GH receptor, triggers JAK2/STAT5 signaling, and raises IGF-1, the downstream hormone that mediates much of GH's anabolic action [1]. Each step is a documented link, which is why the hormone telemetry is the part of this compound's record that reads cleanly.
The sustained-stimulation design is the deliberate engineering choice. Native GHRH is destroyed within minutes; the four substitutions block that, and albumin conjugation in the DAC variant holds the signal for days [2]. The result measured in healthy adults was a 2- to 10-fold GH rise sustained for six days or more on a single dose [1] — a long-residence GHRH signal rather than an exogenous GH bolus.
What this log does not measure
The honest readout matters as much as the measured one. There are no large human efficacy trials and no long-term human safety data for CJC-1295 [1]. The ConjuChem Phase 2 program in HIV-associated visceral obesity (NCT00267527) was discontinued, and the long-acting DAC program did not advance [7]. CJC-1295 is unapproved for human use anywhere; the 2024 FDA Pharmacy Compounding Advisory Committee reviewed the GH-secretagogue class and did not recommend it for the 503A compounding bulks list [1]. And it is prohibited at all times in sport under WADA Section S2 [1]. Those flagged lines — not a list of promised benefits — are the rest of the record.