CJC-1295

What it is

CJC-1295 is a synthetic analogue of human growth hormone-releasing hormone (GHRH/hGRF 1-29). It incorporates a reactive maleimidopropionic acid group (Drug Affinity Complex, DAC) at its C-terminus that allows covalent binding to free thiols on endogenous plasma proteins, primarily serum albumin (Cys34), markedly extending its plasma half-life to approximately 5.8–8.1 days in humans. By acting as a long-lasting GHRH receptor agonist at anterior pituitary somatotrophs, CJC-1295 stimulates dose-dependent increases in GH secretion and downstream IGF-1 production. GH pulsatility is preserved, but trough (basal) GH levels are markedly elevated, which appears to drive the observed increases in IGF-1. In rodent models, CJC-1295 has been shown to activate IGF-1 signalling and satellite cell repair pathways, rescue growth deficits in GHRH-knockout mice by promoting somatotroph proliferation, and restore normal pituitary size, GH, and IGF-1 levels in brain-specific M3 muscarinic receptor knockout mice. It demonstrates enhanced in vitro stability against dipeptidylpeptidase-IV compared to native GHRH.

Class: Growth Hormone-Releasing Hormone (GHRH) Analogue / Growth Hormone Secretagogue

What it's studied for

• Stimulation of GH and IGF-1 secretion in healthy adults (pharmacokinetic/pharmacodynamic characterisation) Human RCT
  • Two randomised, placebo-controlled, double-blind, ascending-dose trials (durations 28 and 49 days) in healthy adults (ages 21–61 yr). Single sc injection produced dose-dependent 2- to 10-fold increases in mean plasma GH for ≥6 days and 1.5- to 3-fold increases in IGF-I for 9–11 days. Estimated half-life 5.8–8.1 days. M PMID 16352683 Teichman SL et al. J Clin Endocrinol Metab. 2006;91(3):799-805.
  • Clinical trial in healthy men aged 20–40 yr. A single injection of CJC-1295 (60 or 90 µg/kg) increased trough GH levels 7.5-fold (P<0.0001), mean GH 46% (P<0.01), and IGF-I 45% (P<0.001) while preserving GH pulsatility. No significant difference between the two doses. PMID 17018654 Ionescu M, Frohman LA. J Clin Endocrinol Metab. 2006;91(12):4792-4797.
• Identification of GH/IGF-1-related serum protein biomarkers Human observational
  • Sera from 11 healthy young adult men analysed by 2D gel electrophoresis before and 1 week after CJC-1295 injection. Apolipoprotein A1 and transthyretin isoforms decreased; beta-hemoglobin and C-terminal albumin fragments increased. A linear relationship was found between an immunoglobulin/albumin fragment spot and IGF- PMID 19386527 Sackmann-Sala L et al. Growth Horm IGF Res. 2009;19(3):242-248.
• Normalisation of growth in GHRH-deficient (knockout) mice Animal studies only
  • Three groups of 1-week-old GHRHKO mice treated for 5 weeks with 2 µg CJC-1295 every 24, 48, or 72 hours. Daily dosing normalised body weight, length, and bone length. Less frequent dosing produced partial improvements. CJC-1295 increased total pituitary RNA and GH mRNA, consistent with somatotroph proliferation. PMID 16822960 Alba M et al. Am J Physiol Endocrinol Metab. 2006;291(6):E1290-1294.
  • In Sprague-Dawley rats, CJC-1295 (the best-performing of three maleimido derivatives of hGRF(1-29)) produced a 4-fold increase in GH AUC over 2 h compared with hGRF(1-29). CJC-1295 was detectable in plasma beyond 72 h and formed a covalent albumin conjugate within 15 min persisting beyond 24 h. PMID 15817669 Jetté L et al. Endocrinology. 2005;146(7):3052-3058.
• Rescue of growth deficit in brain-specific M3 muscarinic receptor knockout mice Animal studies only
  • Treatment of Br-M3-KO mice (dwarf phenotype, anterior pituitary hypoplasia) with CJC-1295 rescued the growth deficit, restoring normal pituitary size and normal serum GH and IGF-1 levels, supporting a model in which central M3 receptors regulate hypothalamic GHRH neuronal function. PMID 19332789 Gautam D et al. Proc Natl Acad Sci USA. 2009;106(16):6829-6834.
• Improvement of muscle performance in glucocorticoid-induced muscle loss (murine model) Animal studies only
  • CJC-1295 combined with ipamorelin showed significantly improved maximum tetanic tension in murine models with glucocorticoid-induced muscle loss. Findings are limited to animal studies. PMID 41476424 Mayfield CK et al. Am J Sports Med. 2026 (PMID: 41476424)
• Anti-doping / forensic detection in urine and plasma (analytical methodology) In vitro only
  • In vitro metabolism of CJC-1295 and CJC-1295 with DAC characterised; 19 major metabolites identified. LC-MS/MS method developed with LODs generally ≤1 ng/mL in urine. PMID 34665524 Memdouh S et al. Drug Test Anal. 2021;13(11-12):1730-1744.
  • Nano-LC-Q/Orbitrap MS method for CJC-1295 (and other GHRH analogs) in urine validated per WADA guidelines; LOD ≤0.5 ng/mL; LOI 0.5–0.75 ng/mL. PMID 41138283 Uçaktürk E, Nemutlu E. J Pharm Biomed Anal. 2026 (PMID: 41138283)
  • Immuno-PCR assay in equine plasma detected CJC-1295-protein conjugate down to 0.8 pg/mL; screening threshold of 50 pg/mL established. Confirmed illicit use in thoroughbred racehorses. PMID 30489688 Timms M et al. Drug Test Anal. 2019;11(7):1014-1023.
• Performance and image enhancement (bodybuilding/recreational use — characterised via netnography and forum analysis) Human observational
  • Netnographic analysis of 23 female-focused online forum discussion threads about CJC-1295. Users reported using it for weight loss, muscle enhancement, youthful skin, improved sleep, and injury healing. Concerns were expressed about gender-specific dosage estimation and long-term consequences. PMID 26771670 Van Hout MC, Hearne E. Subst Use Misuse. 2016;51(9):1135-1142.

Community-reported dosing

Tier key: Research = PMID-cited study · [C] = scraped community source · [S] = model-synthesized from aggregate community reports (softer evidence). How we source.

Safety signals

• No serious adverse reactions were reported in the two randomised, placebo-controlled clinical trials at doses of 30 or 60 µg/kg sc; the compound was described as 'safe and relatively well tolerated, particularly at doses of 30 or 60 µg/kg'. PMID 16352683
• Potential class-level adverse effects of GH-axis secretagogues include prolactin and cortisol elevations, appetite changes, dysglycaemia, fluid retention, musculoskeletal symptoms (myalgia/arthralgia), and injection-site reactions — noted for GH-axis peptides as a group including CJC-1295. PMID 42395176
• Emerging data on GH secretagogues and related peptides used in sport highlight potential risks of cardiovascular strain, insulin resistance, dyslipidaemia, and psychiatric instability, though these are described as a class concern and not specifically quantified for CJC-1295 alone. PMID 41880199
• Indications, dosing, frequency, duration, safety, and efficacy of CJC-1295 for clinical or orthopaedic use remain unknown; significant research is required before definitive recommendations can be made. PMID 41476424
• Non-approved peptides including CJC-1295 lack long-term safety data and systematic validation; significant knowledge gaps include optimal dosing regimens and combination therapy effects. PMID 42021992
• Illicitly manufactured preparations containing CJC-1295 have been identified by law enforcement, raising concerns about product quality, purity, and contamination in the unregulated supply chain. PMID 21204297
• Widespread product mislabelling and contamination have been noted for peptides in the unregulated 'gray market', including CJC-1295; uncertain product composition, dose, and stacking practices increase risk. PMID 42395176

Contraindications

• Use by competitive athletes is prohibited under WADA regulations; competitive athletes are contraindicated from using CJC-1295 outside of an approved therapeutic use exemption. PMID 41138283
• The reviewed literature does not enumerate specific medical contraindications (e.g., pregnancy, malignancy, specific disease states) for CJC-1295. Absence of approval and absence of long-term human safety data preclude clinical use outside of research settings. PMID 41966639