Key findings
- The compound is a tetrasubstituted form of the 1-29 fragment carrying an N-epsilon-3-maleimidopropionamide derivative of lysine at the C terminus. [1]
- Three maleimido derivatives conjugated to human serum albumin ex vivo all showed enhanced in-vitro stability against dipeptidylpeptidase IV and all were active in a growth hormone secretion assay on cultured rat anterior pituitary cells. [1]
- Once conjugated the construct behaves as a macromolecule of undefined mass, so the cited screens used immuno-polymerase chain reaction or immuno-affinity capture with tryptic digestion rather than top-down mass spectrometry. [2][3]
- In-vitro metabolism work lists CJC-1295 and CJC-1295 with drug affinity complex as separate target analytes, which makes the modification an analytical question rather than a naming one. [4]
Identity and structure
- Parent sequence
- A tetrasubstituted form of human growth hormone releasing factor 1-29 [1]
- Reactive group
- An N-epsilon-3-maleimidopropionamide derivative of lysine at the C terminus, described elsewhere as a maleimidopropionic acid group that links covalently to free thiols on plasma proteins [1][2]
- Length
- A 30 amino acid peptide in the cited detection work [2]
- Drug affinity complex status
- Detection work lists CJC-1295 and CJC-1295 with drug affinity complex as distinct target analytes, so a catalog name alone does not establish which form is supplied [4]
- Form as supplied
- Sterile lyophilized powder
Mechanism as studied
Conjugation takes place at the free thiol of Cys34 on serum albumin. The discovery work synthesised three maleimido derivatives of the 1-29 fragment, conjugated them to human serum albumin ex vivo, and found all three resistant to dipeptidylpeptidase IV in vitro and active on cultured rat anterior pituitary cells. [1]
A Western blot of plasma from a rat given the compound showed immunoreactive material on the serum albumin band from 15 min and still present beyond 24 h, which the authors read as conjugation occurring in circulation rather than only in the vial. [1]
Research findings
In vitro
- System
- Three maleimido derivatives of the 1-29 fragment conjugated ex vivo to human serum albumin, assayed on cultured rat anterior pituitary cells
- Measured
- Stability against dipeptidylpeptidase IV and growth hormone secretion from the cultured cells
- Reported
- All three albumin conjugates showed enhanced in-vitro stability against dipeptidylpeptidase IV and were bioactive in the growth hormone secretion assay. [1]
Preclinical in vivo
- System
- Normal male Sprague Dawley rats given the maleimido derivatives, with plasma sampling and Western blot analysis
- Measured
- Growth hormone area under the curve over 2 h, persistence of the compound in plasma, position of the immunoreactive band
- Reported
- The selected compound gave a fourfold larger growth hormone area under the curve than the unmodified 1-29 fragment and was present in plasma beyond 72 h. Immunoreactive material appeared on the serum albumin band after 15 min and remained in circulation beyond 24 h. [1]
Analytical
- System
- Equine plasma with a pair of monoclonal antibodies raised against the peptide, read by immuno-polymerase chain reaction
- Measured
- Limit of detection for the peptide protein conjugate and the screening threshold imposed by endogenous equine growth hormone releasing hormone
- Reported
- The assay detected the conjugate down to 0.8 pg/mL. Endogenous equine growth hormone releasing hormone required a screening threshold of 50 pg/mL. [2]
Analytical
- System
- Equine plasma after immuno-affinity capture and tryptic digestion, read by liquid chromatography tandem mass spectrometry
- Measured
- Confirmation of the peptide and the lowest concentration identified in 1 mL of plasma
- Reported
- The method identified the peptide down to 180 pg/mL in 1 mL of equine plasma, which the authors present as a confirmation step following an immuno-polymerase chain reaction screen. [3]
Analytical
- System
- Fortified urine containing sermorelin, tesamorelin, CJC-1295 and CJC-1295 with drug affinity complex, plus nineteen synthesized in-vitro metabolites as reference materials
- Measured
- Identity of the in-vitro metabolites and limits of detection by liquid chromatography tandem mass spectrometry
- Reported
- Nineteen major in-vitro metabolites were identified across the four analogues, then synthesized, purified and characterized in house. Limits of detection were generally 1 ng/ml or less. [4]
Analytical
- System
- Human plasma captured with a polyclonal growth hormone releasing hormone antibody on monolithic tips, read by nano ultrahigh performance liquid chromatography and high resolution tandem mass spectrometry
- Measured
- Specificity, linearity, recovery, lower limit of detection and imprecision for four analogues and two of their metabolites
- Reported
- Recovery ran from 19 to 37 percent, the lower limit of detection was below 50 pg/mL and imprecision stayed below 20 percent. The four analogues, listed as Geref, CJC-1293, CJC-1295 and Egrifta, were captured and separated in one method. [5]
Handling for in-vitro work
- Conjugation in cited work
- The maleimido derivatives were conjugated to human serum albumin ex vivo before assay [1]
- Storage
- Lyophilized material kept at minus 20 degrees C, dark and dry; reconstituted aliquots kept cold and used promptly
Open questions
- No cited study reports how long the reactive maleimide group survives in solution or in storage, so the shelf behaviour of the unconjugated material is not established here.
- Which of CJC-1295 and CJC-1295 with drug affinity complex a listing supplies is an analytical identity question; the cited methods distinguish the two forms but no cited study reports a result for catalog material.
Lot records
Check the record for the exact material you order. A published paper and a batch certificate answer different questions.
- RV-24-0015-2 ↗CJC-1295 with DAC · 99.40% HPLC2026-09-22
- RV-24-0015-1 ↗CJC-1295 with DAC · 99.40% HPLC2026-09-16
References
- 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.
- Timms M, Ganio K, Forbes G, et al. An immuno polymerase chain reaction screen for the detection of CJC-1295 and other growth-hormone-releasing hormone analogs in equine plasma. Drug testing and analysis. 2019.
- Timms M, Ganio K, Steel R A method for confirming CJC-1295 abuse in equine plasma samples by LC-MS/MS. Drug testing and analysis. 2019.
- Memdouh S, Gavrilović I, Ng K, et al. Advances in the detection of growth hormone releasing hormone synthetic analogs. Drug testing and analysis. 2021.
- Knoop A, Thomas A, Fichant E, et al. Qualitative identification of growth hormone-releasing hormones in human plasma by means of immunoaffinity purification and LC-HRMS/MS. Analytical and bioanalytical chemistry. 2016.
Publication records fetched from PubMed on 2026-09-20. Profile text reviewed 2026-09-20.