CJC-1293
[D-Ala2]-hGRF(1-29)-NH2, D-Ala2 sermorelin analogue, GHRH(1-29) D-Ala2 amide
CJC-1293 is a growth hormone-releasing hormone analogue: the 1-29 fragment of human GHRH with D-alanine substituted for L-alanine at position 2, which blocks the enzyme that normally destroys the molecule within minutes. It is a stereoisomer of sermorelin differing at exactly one chiral centre. Almost everything published about it comes from anti-doping laboratories developing detection methods; there is no published efficacy or pharmacokinetic data in humans.
Mechanism
CJC-1293 acts at the growth hormone-releasing hormone receptor (GHRHR), a class B G-protein-coupled receptor on anterior pituitary somatotrophs. Receptor binding raises intracellular cyclic AMP through Gs and adenylyl cyclase, activating protein kinase A, which triggers exocytosis of stored growth hormone and increases transcription of the GH1 gene. Because it works through the GHRH receptor rather than the ghrelin receptor, it is pharmacologically distinct from the GHRPs and preserves the pulsatile, feedback-regulated pattern of growth hormone secretion: somatostatin tone and IGF-1 negative feedback continue to operate, which is the principal theoretical safety argument for secretagogues over exogenous growth hormone.
The single modification that defines CJC-1293 is the replacement of L-alanine with D-alanine at position 2. Native GHRH(1-29) is cleaved between residues 2 and 3 by dipeptidyl peptidase-4, which is why sermorelin survives only about eleven minutes in plasma. A D-amino acid at position 2 is not recognised by that protease, so the primary degradation route is closed. Analytical work confirms the relationship directly: a 2023 capillary electrophoresis study describes sermorelin and CJC-1293 as enantiopeptides that differ by the chirality of only one amino acid and require a chiral selector, dimethyl-beta-cyclodextrin, to separate them. This matters for reading the compound correctly, because CJC-1293 is frequently confused in commercial descriptions with CJC-1295. They are not the same. CJC-1295 carries multiple substitutions and, in its drug affinity complex form, a maleimidopropionamide linker at a thirtieth lysine residue that covalently binds circulating albumin, giving a half-life measured in days. The unconjugated CJC-1293 described in the anti-doping literature has one substitution and no albumin linker, so it is a short-acting molecule. Confusingly, some chemical databases index a DAC-conjugated structure under the CJC-1293 name; anyone reading a datasheet should check the molecular weight rather than the label.
What the research shows
The published record on CJC-1293 consists, essentially entirely, of anti-doping analytical chemistry. Knoop and colleagues in Cologne developed an immunoaffinity purification and high-resolution mass spectrometry method for qualitative identification of GHRH analogues in human plasma, with CJC-1293 as one of four named target analytes alongside sermorelin, CJC-1295 and tesamorelin, achieving detection below 50 picograms per millilitre. Otin and colleagues developed a capillary electrophoresis method able to resolve CJC-1293 from sermorelin despite their single-centre stereochemical difference. Thomas and colleagues published an expanded immunoaffinity screening method for peptides above 2 kilodaltons that covers growth hormone-releasing hormones as a group. Between them these papers establish that CJC-1293 exists, circulates in identifiable form, and is considered enough of a doping risk to warrant dedicated detection methods.
What they do not establish is any biological effect. There is no published randomised trial, no open-label human study, no dose-ranging work, no pharmacokinetic profile, no measured growth hormone or IGF-1 response, and no animal efficacy study identified under this designation. Its parent compound sermorelin was licensed in the United States for paediatric growth hormone deficiency and was discontinued there in 2008, a withdrawal generally reported as commercial rather than safety-driven. Its better-known sibling CJC-1295 with drug affinity complex was taken into human trials and produced sustained IGF-1 elevation, but that development programme did not deliver an approved product. CJC-1293 has not reached even that stage. Assuming that a single D-alanine substitution converts sermorelin into a meaningfully better therapeutic is a hypothesis, not a finding, and the hypothesis has not been tested in any published human study.
Evidence assessment
Preclinical only
There is no published human efficacy or pharmacokinetic study of CJC-1293 in any design, and no animal efficacy study identified under this name. The entire indexed literature is analytical method development for anti-doping detection, and the animal work within those papers (in the Knoop study) concerns detectability rather than effect. Preclinical is the highest tier the evidence can support, and even that overstates the depth of the biological data.
Tiers are applied consistently across the library and re-checked when new trials read out. Read the grading method.
Key studies
Qualitative identification of growth hormone-releasing hormones in human plasma by means of immunoaffinity purification and LC-HRMS/MS Preclinical only
A validated immunoaffinity and high-resolution mass spectrometry method detected four GHRH analogues - sermorelin, CJC-1293, CJC-1295 and tesamorelin - and their metabolites at below 50 picograms per millilitre. Intact compounds persisted for at least four hours after administration in animals, and a sermorelin metabolite was detected in a human volunteer's plasma after injection.
Online large volume sample stacking preconcentration and separation of enantiomeric GHRH analogs by capillary electrophoresis Preclinical only
Achieved separation of basic GHRH peptide analogues including the enantiopeptides sermorelin and CJC-1293, which differ by the chirality of only one amino acid, with detection limits of 75-200 ng/ml and a signal enhancement factor of 640 over the standard method.
Expanded test method for peptides >2 kDa employing immunoaffinity purification and LC-HRMS/MS Preclinical only
Combined ultrafiltration, immunoaffinity purification with coated paramagnetic beads, nano-UHPLC and high-resolution tandem mass spectrometry to cover growth hormone-releasing hormones, insulins and related substances, with recoveries of 11-69 per cent and detection limits of 5-100 pg in urine and 0.1-2 ng in plasma.
In-house standards derived from doping peptides: Enzymatic and serum stability and degradation profile of GHRP and GHRH-related peptides Preclinical only
Matrix effects and sample pretreatment significantly affected recovery from biological matrices; GHRP-4, GHRP-6 and sermorelin(22-29) were stable enough to serve as in-house internal standards.
Safety
There are no published human safety data for CJC-1293 specifically. The relevant safety framework is that of GHRH analogues generally, where the best characterised member is tesamorelin: injection site reactions, arthralgia, peripheral oedema, paraesthesia and deterioration in glucose tolerance with increased incidence of diabetes on prolonged exposure. Because GHRH analogues raise IGF-1, theoretical concerns about growth stimulation of existing neoplasia apply, and tesamorelin's labelling carries corresponding contraindications in active malignancy. Sermorelin, the closely related parent, was generally well tolerated in paediatric use, with flushing and injection site reactions the main issues. None of that is a substitute for data on this molecule. Compounding the problem, material sold online under the CJC-1293 name is frequently mislabelled: vials sold as CJC-1293 may contain tetrasubstituted modified GRF(1-29), CJC-1295 with or without the albumin linker, or nothing identifiable, and identity, purity, endotoxin content and sterility are unverified.
Regulatory status
| Jurisdiction | Status |
|---|---|
| United Kingdom | No UK marketing authorisation. Supply for human use would constitute supply of an unlicensed medicinal product under the Human Medicines Regulations 2012. Among GHRH analogues, tesamorelin has no UK marketing authorisation either. |
| United States | Not approved by the FDA for any indication. It is an unapproved new drug, not a lawful dietary supplement ingredient, and is sold only as a research chemical labelled not for human consumption. Its parent sermorelin was formerly licensed for paediatric growth hormone deficiency and was discontinued in the United States in 2008; it is not currently an FDA-approved product. |
| WADA (sport) | Prohibited at all times, in and out of competition. Growth hormone-releasing hormone analogues fall under section S2.2.3 of the WADA Prohibited List and CJC-1293 is named among the examples there. Validated plasma detection methods exist. The draft cited section S2.1, which is the erythropoietin section and is incorrect. |
Questions
No, and this is the most common error made about it. CJC-1293 is GHRH(1-29) amide with one substitution, D-alanine at position 2. Modified GRF(1-29), often sold as CJC-1295 without DAC, carries several further substitutions. CJC-1295 with DAC adds an albumin-binding linker on a thirtieth residue and lasts for days. Three different molecules, routinely conflated in commercial listings - and some chemical databases add to the confusion by filing a DAC-conjugated structure under the CJC-1293 name.
By one chiral centre. Sermorelin is GHRH(1-29) amide with all L-amino acids; CJC-1293 has D-alanine instead of L-alanine at position 2. That change blocks cleavage by dipeptidyl peptidase-4, the enzyme that limits sermorelin to about eleven minutes in plasma. A 2023 capillary electrophoresis study describes the pair as enantiopeptides requiring a chiral selector to tell them apart.
None have been published. The entire indexed literature on it is anti-doping method development. There is no published growth hormone response curve, no IGF-1 data, no pharmacokinetics and no safety study in humans.
Yes, at all times. GHRH analogues fall under section S2.2.3 of the WADA Prohibited List and CJC-1293 is named there. Anti-doping laboratories have validated plasma and urine methods that can distinguish it from sermorelin despite the single stereochemical difference.