CJC-1295 No DAC Research, Specifications & Scientific Information

Introduction

CJC-1295 no DAC is among the more confusingly named materials in the peptide catalogue, and untangling the name is the first useful thing a reference page can do. The name belongs to a molecule that is not CJC-1295. CJC-1295, as defined in the paper that named it, is a tetrasubstituted form of human growth hormone-releasing factor 1-29 carrying an additional lysine at the C-terminus with a maleimidopropionamide group attached — the drug affinity complex, or DAC, that bonds the peptide covalently to the free thiol on cysteine 34 of circulating albumin ^[5]. Remove that group and what remains is the substituted 29-residue chain listed as CJC-1295 no DAC, or as modified GRF (1-29).

The distinction is not pedantry. Nearly every quantitative figure attached to this material in secondary sources was measured on the conjugate rather than on the unconjugated peptide. This page sets out what has been published about the 29-residue analogue itself, what has been published about the molecules either side of it, and which is which.

What Is CJC-1295 No DAC?

CJC-1295 no DAC is a synthetic peptide analogue of growth hormone-releasing hormone, the hypothalamic peptide that drives growth hormone secretion from the anterior pituitary. It is not an approved medicine anywhere, and no clinical trial has been registered or published under this name.

Three facts define it structurally. It is a 1-29 fragment: the native hormone is 44 amino acids long, and the first 29 are the portion that retains full activity at the receptor, which is why almost every synthetic analogue in this family is built on that shortened chain. It carries four substitutions relative to that fragment — D-alanine for L-alanine at position 2, glutamine for asparagine at 8, alanine for glycine at 15, and leucine for methionine at 27. And it lacks the conjugating group that defines CJC-1295 proper.

The substituted 29-residue chain has no entry of its own in any public chemical register. The FDA/NCATS Global Substance Registration System records CJC-1295 — the conjugating form — as a 30-residue chain under UNII 62RC32V9N7, and records the unmodified fragment separately as sermorelin. The molecule in between has no register record, which is why the identifier fields on this page are published as unknown.

CJC-1295 No DAC Specifications

The string above is written in single-letter code with a lower-case 'a' at position 2 to mark D-alanine; every other letter is a standard L-amino acid, and the chain terminates in a C-terminal amide. Read against human growth hormone-releasing hormone 1-29 — the sequence that the FDA/NCATS Global Substance Registration System records for sermorelin under UNII 89243S03TE — this analogue differs at four positions: D-alanine for L-alanine at 2, glutamine for asparagine at 8, alanine for glycine at 15, and leucine for methionine at 27. No public register carries a separate record for the unconjugated analogue under the name CJC-1295 no DAC, so there is no register-supplied CAS number, UNII or PubChem identifier for it; the four substitutions shown are those recorded in the GSRS entry for CJC-1295 itself (UNII 62RC32V9N7), whose 30-residue chain is this sequence plus a C-terminal lysine carrying the maleimidopropionamide group that the unconjugated analogue does not have. Registry numbers that circulate in commercial listings for this material belong to other substances and are not reproduced here. The molecular formula and mass are the reference values carried in the supplier catalog for the material offered as a laboratory reagent; the certificate of analysis supplied with a laboratory order is the record for a given lot.

Values that a public register does not carry are shown as not publicly characterised rather than estimated. Identifiers are reference values; the certificate of analysis supplied with a laboratory order is the record for a given lot.

How Does CJC-1295 No DAC Work?

The target is the growth hormone-releasing hormone receptor, cloned from human anterior pituitary in 1993 and shown there to be a G protein-coupled receptor of the class that signals through Gs and cyclic AMP ^[3]. Receptor occupancy on a pituitary somatotroph raises intracellular cyclic AMP, and that is the proximate step in growth hormone release. The receptor sits in the same structural class as the receptors for glucagon, GLP-1 and secretin.

What the four substitutions are for is a separate question from what the molecule binds. Three of them — positions 8, 15 and 27 — are drawn from a body of structure-activity work on hGH-RH(1-29) analogues in which substitutions at those positions were associated with greater potency and greater stability than the parent fragment in rat pituitary cell systems ^[4]. The substitution at position 2 addresses a specific enzyme, and it is the best characterised of the four.

CJC-1295 No DAC Mechanism of Action

In vitro research

Native growth hormone-releasing hormone does not survive long in plasma, and the reason was established precisely in 1989. The primary proteolytic event is cleavage at the 2-3 amino acid bond by dipeptidylpeptidase IV. The work that established this tested the native 44-residue hormone, the 40-residue acid form, and the shortened 1-32 and 1-29 amides: all were rapidly cleaved at that site, conversion was blocked by a competitive dipeptidylpeptidase IV inhibitor, and — the point that matters here — substituting a D-amino acid at either position 1 or position 2 prevented the hydrolysis altogether ^[1]. The same study found a secondary trypsin-like cleavage at positions 11-12, and at 12-13 in the shortened 1-29 and 1-32 forms.

That is the mechanistic basis for D-alanine at position 2 in this analogue, and it is an in vitro and ex vivo finding about an enzyme, not a measurement made on this molecule.

The specificity of that enzyme is not absolute. Work on bovine growth hormone-releasing factor analogues found that dipeptidylpeptidase IV from pig kidney still cleaved analogues substituted at position 2 with serine, threonine or valine, which extended the then-understood substrate specificity of the enzyme beyond penultimate proline, hydroxyproline and alanine ^[2]. A substitution at position 2 is therefore not automatically a block; the stereochemistry matters.

In the discovery work on the conjugates, the maleimido derivatives of hGRF(1-29) showed enhanced in vitro stability against dipeptidylpeptidase IV and were bioactive in a growth hormone secretion assay in cultured rat anterior pituitary cells ^[5]. Those assays were run on the conjugating derivatives, not on the unconjugated tetrasubstituted chain.

What Is CJC-1295 No DAC Being Researched For?

Very little, under this name. A search of the peer-reviewed literature and of public trial registers returns no study whose subject is the unconjugated tetrasubstituted hGRF(1-29) analogue. What exists instead falls into three groups:

• Structure-activity chemistry on hGH-RH(1-29) analogues, which is where the substitutions came from ^[4].
• Enzymology of growth hormone-releasing hormone clearance, which is why position 2 is substituted ^{[1, 2]}.
• Analytical and anti-doping chemistry, which is the one field actively publishing on materials sold under the CJC-1295 names ^{[7, 8]}.

The absence of a clinical literature on this specific molecule is the single most important thing on this page, and it is not remedied by the existence of clinical work on the conjugate.

Preclinical Research on CJC-1295 No DAC

Animal research

The animal work most often associated with this material is the 2005 study that identified CJC-1295, and it is worth being exact about what that study administered. Three maleimido derivatives of hGRF(1-29) were synthesised and bioconjugated to human serum albumin ex vivo; the derivatives were then administered subcutaneously to normal male Sprague Dawley rats, where each produced an acute rise in plasma growth hormone. The best of the three, designated CJC-1295, showed a fourfold increase in growth hormone area under the curve over two hours compared with hGRF(1-29), was still detectable in plasma beyond 72 hours, and appeared on Western blot at the band corresponding to serum albumin from 15 minutes onward ^[5].

The comparator in that experiment was the unmodified hGRF(1-29) fragment. The unconjugated tetrasubstituted chain — the material this page describes — was not one of the compounds administered.

Separately, substituted hGH-RH(1-29) analogues carrying replacements at positions including 8, 15 and 27 were administered subcutaneously and intravenously to rats and were reported as substantially more potent than hGH-RH(1-29) amide at 15 and 30 minutes, with higher binding affinity at pituitary growth hormone-releasing hormone receptors ^[4]. Those analogues are relatives of this molecule, not this molecule.

Findings described in this section were observed in animals, and none of them establishes anything about humans.

Other Areas of CJC-1295 No DAC Research

In vitro research

The field that has published most consistently on materials carrying the CJC-1295 names is analytical chemistry, and the reason is enforcement rather than pharmacology. A 2010 report described the identification of CJC-1295 in an unknown pharmaceutical preparation seized outside any regulated supply chain, using mass spectrometric characterisation ^[7]. A later review set out the methods developed for detecting synthetic growth hormone-releasing hormone analogues in biological matrices, a problem complicated by the fact that these analogues differ from the endogenous hormone by a handful of residues ^[8].

This literature is about identifying molecules, not about what they do. It is cited here because it is the most reliable published characterisation of what circulates under these names, and because it documents that the naming in commercial listings is inconsistent enough to require instrumental confirmation.

Current Research Status

Status as of September 22, 2026. This block is rendered from maintained fields, not from prose, so it cannot go stale in one place and stay current in another.

CJC-1295 No DAC vs Related Compounds

The compounds this material is usually set beside differ from it in defined structural ways. Nothing below compares them on any measure of effect.

Chain length

Sermorelin and CJC-1295 no DAC are both 29 residues; tesamorelin is 44; CJC-1295 with DAC is 30.

Substitutions

Sermorelin is the unmodified 1-29 fragment. CJC-1295 no DAC carries four substitutions. CJC-1295 with DAC carries the same four plus a C-terminal lysine bearing the albumin-binding group ^[5]. Tesamorelin is the full 1-44 sequence with a hexenoyl group on the N-terminal tyrosine.

Receptor

All four act at the growth hormone-releasing hormone receptor ^[3]. The ghrelin-receptor secretagogues — ipamorelin, GHRP-2, GHRP-6 — act at a different receptor entirely and are not analogues of this family.

Evidence base

Tesamorelin has a substantial published clinical literature and an approved product in a defined indication. Sermorelin has a published human literature and a withdrawn approved product. CJC-1295 with DAC has early-phase human pharmacokinetic data ^[6]. CJC-1295 no DAC has none of these.

Chemical & Molecular Characteristics

The sequence recorded on this page, YaDAIFTQSYRKVLAQLSARKLLQDILSR, is written with a lower-case letter at position 2 to mark D-alanine; every other position is a standard L-amino acid and the chain ends in a C-terminal amide. Three points qualify it.

It is a derived sequence, not a register record. No public register carries an entry for the unconjugated analogue. The chain above is the 1-29 portion of the 30-residue sequence recorded for CJC-1295 in the Global Substance Registration System under UNII 62RC32V9N7, which carries the same four substitutions and adds the conjugating lysine at position 30. Presenting it as a register record for this material would overstate what the registers actually say.

The identifier fields are empty on purpose. There is no CAS registry number, no UNII and no PubChem compound identifier published for the unconjugated analogue. Numbers that circulate in commercial listings for this material are registry numbers belonging to other substances, and reproducing one here would be worse than leaving the field blank.

The formula and mass are catalog reference values. The molecular formula C152H252N44O42 and the molecular weight 3367.9 g/mol are the figures carried in the supplier catalog for the material offered as a laboratory reagent. They are consistent with a 29-residue amide differing from the sermorelin sequence at the four positions described, but no independent register confirms them, and the certificate of analysis supplied with a laboratory order is the record for a given lot.

Analytical Specifications

Analytical figures are lot-specific. Fields the catalog does not carry for the current lot are omitted rather than filled with a typical value. The certificate of analysis and the safety data sheet for the exact lot supplied are provided with a laboratory order; no purity figure on this page is a substitute for that document.

Frequently Asked Questions

Scientific References

1. Frohman LA, Downs TR, Heimer EP, et al.. Dipeptidylpeptidase IV and trypsin-like enzymatic degradation of human growth hormone-releasing hormone in plasma The Journal of clinical investigation; 1989. PMID 2565342 doi:10.1172/JCI114049
2. Martin RA, Cleary DL, Guido DM, et al.. Dipeptidyl peptidase IV (DPP-IV) from pig kidney cleaves analogs of bovine growth hormone-releasing factor (bGRF) modified at position 2 with Ser, Thr or Val. Extended DPP-IV substrate specificity? Biochimica et biophysica acta; 1993. PMID 8102071 doi:10.1016/0167-4838(93)90256-q
3. Gaylinn BD, Harrison JK, Zysk JR, et al.. Molecular cloning and expression of a human anterior pituitary receptor for growth hormone-releasing hormone Molecular endocrinology (Baltimore, Md.); 1993. PMID 7680413 doi:10.1210/mend.7.1.7680413
4. Izdebski J, Pinski J, Horvath JE, et al.. Synthesis and biological evaluation of superactive agonists of growth hormone-releasing hormone Proceedings of the National Academy of Sciences of the United States of America; 1995. PMID 7761415 doi:10.1073/pnas.92.11.4872
5. Jetté L, Léger R, Thibaudeau K, et al.. Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog Endocrinology; 2005. PMID 15817669 doi:10.1210/en.2004-1286
6. Teichman SL, Neale A, Lawrence B, et al.. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults The Journal of clinical endocrinology and metabolism; 2006. PMID 16352683 doi:10.1210/jc.2005-1536
7. Henninge J, Pepaj M, Hullstein I, et al.. Identification of CJC-1295, a growth-hormone-releasing peptide, in an unknown pharmaceutical preparation Drug testing and analysis; 2010. PMID 21204297 doi:10.1002/dta.233
8. Memdouh S, Gavrilović I, Ng K, et al.. Advances in the detection of growth hormone releasing hormone synthetic analogs Drug testing and analysis; 2021. PMID 34665524 doi:10.1002/dta.3183

Every identifier above is resolved against PubMed, Crossref or ClinicalTrials.gov at build time, and the title returned by the register is compared with the title stored here. A page does not publish if a reference fails to resolve.

Research-Use Information

For in vitro research use only. This material is a laboratory reagent. It is not a drug, food, dietary supplement, or cosmetic and is not for human or veterinary use, including ingestion, injection, or any other administration. No information on this page describes or implies any effect in humans or animals. Sold only to researchers under our Terms of Sale.

Related laboratory reagent: CJC-1295 No DAC specifications and lot documentation