Index 00 / CJC-1295 / GHRH (1-29) Analog / DAC Variant
CJC-1295: An online reading of the GHRH analog, its DAC variant, and the pharmacokinetics separating them.
A journal-supplement reading of the published record on CJC-1295 — the four amino-acid substitutions, the maleimidopropionyl-lysine albumin linker, the human Phase 1 pharmacokinetics, and the 2006 Phase 2 trial that halted industry development.
Fig. 00 / DAC vs. modified GRF 1-29 plasma curves / schematic
Schematic of the two CJC-1295 variant plasma curves on a shared horizontal axis — the DAC variant climbs to a sustained ~8-day plateau (cobalt), the modified GRF 1-29 variant spikes and decays inside ~30 minutes (black). Reconstructed from Teichman 2006 and the modified GRF 1-29 pharmacological record.
Index 01 / Peptide Overview / Structure & DAC Variant
CJC-1295 peptide overview
CJC-1295 is a synthetic 30-amino-acid analog of human growth hormone-releasing hormone (GHRH 1-29) developed by ConjuChem Biotechnologies as the lead validation compound for the Drug Affinity Complex (DAC) albumin-conjugation platform[1]. The backbone carries four engineered substitutions — D-Ala² (resists DPP-IV cleavage), Gln⁸ (prevents asparagine rearrangement), Ala¹⁵ (enhances bioactivity), and Leu²⁷ (prevents methionine oxidation)[2]. The DAC variant attaches a maleimidopropionyl-lysine moiety at position 30 that forms a covalent thioether bond with Cys34 of circulating serum albumin after subcutaneous injection, producing a peptide-albumin complex of approximately 67 kDa[1].
The pharmacokinetic consequence is the central editorial fact of this compound. Native GHRH 1-29 is cleared from plasma within minutes. CJC-1295 without DAC — also called modified GRF 1-29 — extends that to roughly t½ = 30 min. CJC-1295 with DAC extends it to between 5.8 and 8.1 days in healthy adults, with IGF-1 elevation persisting for up to 28 days under weekly or biweekly dosing[3].
What the literature has measured is a long-acting GHRH receptor agonist that preserves the pulsatile pattern of endogenous GH release even under continuous receptor stimulation[4]. What it has not produced is regulatory approval anywhere in the world. Industry development ended after a fatal adverse event in a 2006 Phase 2 trial[5]. The compound sits today in a regulatory limbo: not FDA-approved, removed from FDA Section 503A Category 2 in September 2024, and prohibited at all times by the World Anti-Doping Agency[6][7].
Index 02 / Mechanism / GH & IGF-1 Axis
What CJC-1295 does in the GH/IGF-1 axis
CJC-1295 binds GHRH receptors on anterior pituitary somatotrophs, activates Gs-protein / adenylyl cyclase / cAMP / PKA signaling, and stimulates pulsatile growth hormone release[1]. Downstream, hepatic IGF-1 production rises and remains elevated for days to weeks under the DAC variant[3].
In the first published human study, single subcutaneous doses of CJC-1295-DAC raised mean plasma GH 2- to 10-fold for six days or more and mean plasma IGF-1 1.5- to 3-fold for nine to eleven days[3]. With repeated weekly or biweekly dosing, IGF-1 remained elevated for up to 28 days. A second 2006 study under continuous receptor stimulation reported a 7.5-fold trough GH elevation, a 46% increase in mean GH, and a 45% increase in IGF-1, with pulse frequency and pulse magnitude unchanged from baseline[4]. That last finding is the mechanistic claim that distinguishes long-acting GHRH analogs from direct GH replacement — the pulsatility survives.
A preclinical complement: in GHRH knockout mice, once-daily 2 µg subcutaneous CJC-1295 for five weeks normalized body weight and length and increased pituitary GH mRNA, while dosing every 48 or 72 hours was less effective[8].
Index 03 / What this edition covers
What the index covers
This online edition reads the CJC-1295 record across eight pages. The CJC-1295 mechanism of action, the CJC-1295 with DAC vs without DAC distinction, and the CJC-1295 vs ipamorelin comparison live on the research page. The CJC-1295 dosage and CJC-1295 side effects pages collect the protocol literature and the reported adverse-effect profile respectively. The frequently asked questions index gathers every question this site receives a search-volume signal on, with a direct cited answer. The references page lists every source.
The site is editorial. It summarizes the peer-reviewed record. It does not sell anything, prescribe anything, or recommend doses for humans.
What is CJC-1295?
A synthetic 30-amino-acid analog of growth hormone-releasing hormone (GHRH 1-29) carrying four amino-acid substitutions for proteolytic stability[1][2]. The DAC variant adds a maleimidopropionyl-lysine moiety that binds serum albumin and extends plasma half-life from minutes to roughly 8 days[3].
What does CJC-1295 do?
Binds GHRH receptors on anterior pituitary somatotrophs and stimulates pulsatile growth-hormone release; downstream hepatic IGF-1 rises and remains elevated for days to weeks under sustained dosing[3][4]. The compound acts on the GH/IGF-1 axis and not on the hypothalamic-pituitary-gonadal axis[3].