CJC-1295

CJC-1295 is a synthetic analogue of growth hormone releasing hormone (GHRH). The name properly refers to a version with a drug affinity complex (DAC) that binds albumin, but is also applied to modified GRF(1-29), which lacks DAC.

Last reviewed 2026-10-25 by the PeptideWiki editorial team. Editorial policy.

Overview

CJC-1295 was developed by the Canadian company ConjuChem as a long-acting analogue of growth hormone releasing hormone. It is built on GRF(1-29), the shortest fully active fragment of human GHRH, with four amino acid substitutions that improve stability. In the original compound, a reactive linker called a drug affinity complex (DAC) was added so the peptide would bind covalently to circulating albumin, greatly extending its duration of action compared with native GHRH.

The name is a frequent source of confusion. The peptide sold as "CJC-1295 without DAC" is more accurately called modified GRF(1-29) or tetrasubstituted GRF(1-29): it has the same four substitutions but no albumin-binding linker, so it is short-acting. The two are pharmacologically different compounds. CJC-1295 with DAC reached early human studies; modified GRF(1-29) has very little published clinical data. Neither is an approved drug.

Compare: Ipamorelin vs CJC-1295, CJC-1295 vs sermorelin.

Structure

Both forms share a 29-residue sequence derived from human GHRH(1-29) with four substitutions: D-alanine at position 2, glutamine at position 8, alanine at position 15 and leucine at position 27. These changes reduce cleavage by dipeptidyl peptidase-4, limit asparagine deamidation and methionine oxidation, and improve helical stability. CJC-1295 with DAC adds a C-terminal lysine carrying a maleimidopropionic acid (MPA) group, which reacts with the free cysteine of serum albumin to form a stable conjugate. Modified GRF(1-29) is the same substituted 29-mer with a C-terminal amide and no DAC linker. Expected masses therefore differ substantially between the two.

Mechanism

Both forms act as agonists of the GHRH receptor on anterior pituitary somatotrophs. Receptor activation increases cyclic AMP signaling, stimulating synthesis and release of growth hormone, which in turn raises circulating IGF-1 produced mainly by the liver. Release remains subject to feedback, including inhibition by somatostatin.

The key difference is pharmacokinetic. Once the DAC linker of CJC-1295 conjugates to albumin, the peptide circulates for days rather than minutes, producing sustained elevation of growth hormone and IGF-1 in human studies. Modified GRF(1-29) is cleared rapidly, so its effect resembles the brief pulses produced by native GHRH or sermorelin. How continuous versus pulsatile stimulation affects downstream physiology is not fully established.

Research

Phase 1 studies of CJC-1295 with DAC

Published studies in healthy adults found that CJC-1295 with DAC produced prolonged, dose-dependent increases in growth hormone and IGF-1 lasting days after a single administration, consistent with albumin binding. A related study reported that pulsatile growth hormone secretion was preserved on a background of increased trough levels. These are small early-phase pharmacology studies and do not establish clinical benefit for any condition.

Clinical development status

ConjuChem pursued CJC-1295 with DAC as a potential treatment approach for conditions involving growth hormone deficiency and abdominal fat accumulation, but the program did not progress to late-stage trials or approval. As a result, there are no pivotal efficacy trials, and long-term human safety data are absent. Its main research value today lies in what it showed about albumin-binding strategies for extending peptide half-life.

Modified GRF(1-29)

Modified GRF(1-29) is best described as a stabilized short-acting GHRH analogue. Its four substitutions were explored in the GHRH analogue literature to improve resistance to enzymatic degradation, but there is little published human data on this exact compound as a standalone agent. Much of what is said about it is extrapolated from studies of GHRH(1-29), sermorelin or CJC-1295 with DAC, which is not equivalent evidence.

Albumin-binding drug design

CJC-1295 with DAC is a well-known example of the maleimide-based approach to covalent albumin conjugation, an approach ConjuChem applied to several peptides. Approved long-acting peptides such as semaglutide use a different, non-covalent albumin-binding strategy based on fatty acid side chains. Comparisons of these approaches are relevant to peptide formulation research generally. Covalent and non-covalent albumin binding differ in reversibility and in how the conjugate is cleared.

Regulatory status

Neither CJC-1295 with DAC nor modified GRF(1-29) is approved by the FDA or other major regulators for any use, and neither is an approved drug product. Their status for pharmacy compounding should be checked against current FDA guidance. GHRH analogues are prohibited at all times under section S2 of the WADA Prohibited List, which covers both forms.

Status changes often. See the regulatory tracker for dated updates.

Quality and identity testing

The first question for any COA is which compound it describes. Mass spectrometry must distinguish CJC-1295 with DAC from modified GRF(1-29): the observed mass should match the expected mass for the specific form shown on this page, and the large difference between the two makes mislabeling detectable. For the DAC form, the maleimide group is reactive, so hydrolyzed or adducted species should be checked. For both forms, HPLC purity should be reported, and methionine oxidation (+16 Da), deamidation (+1 Da) and deletion sequences are common impurities in a 29- to 30-residue synthetic peptide. Counter-ion and net peptide content should be stated.

For a walkthrough of each section of a certificate, see how to read a COA.

Storage and stability

Store lyophilized material sealed at -20 °C or below, protected from light and moisture. The DAC form contains a maleimide group that can hydrolyze in aqueous solution and react with thiols, so it should be kept dry and reconstituted only immediately before laboratory use; avoid buffers containing reducing agents or free thiols. Modified GRF(1-29) is more stable than native GHRH but still contains methionine and is prone to oxidation and aggregation in solution. Aliquot to avoid repeated freeze-thaw cycles.

Download the CJC-1295 data sheet (PDF): sequence, masses, expected MS ions and handling on one printable page.

Latest research

Frequently asked questions

Related compounds

• Sermorelin

  Sermorelin is a synthetic peptide consisting of the first 29 amino acids of human growth hormone releasing hormone (GHRH). It was previously FDA-approved as Geref but has been discontinued in the US.

• Tesamorelin

  Tesamorelin is a stabilized synthetic analogue of human growth hormone releasing hormone. It is FDA-approved as Egrifta for reducing excess abdominal fat in adults with HIV-associated lipodystrophy.

• Ipamorelin

  Ipamorelin is a synthetic pentapeptide growth hormone secretagogue that acts as a selective agonist of the ghrelin receptor (GHS-R1a). It is investigational and not approved for any use.

• GHRP-6

  GHRP-6 is a synthetic hexapeptide that stimulates growth hormone release by activating the ghrelin receptor (GHS-R1a). It was one of the first growth hormone secretagogues and is not approved for any use.

References

1. 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. J Clin Endocrinol Metab. 2006. Find on PubMed
2. PubMed: all indexed literature on CJC-1295
3. ClinicalTrials.gov: registered studies mentioning CJC-1295