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Background And Naming Conventions — Worked Examples

By Editorial Desk · published 2025-11-27 · last reviewed 2026-01-15 · Wiki

CJC-1295 raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.

Reviewed 2026-01-15. Anything still debated is marked as such rather than presented as settled.

Background and Naming Conventions

CJC-1295 is a synthetic peptide analog of growth hormone-releasing hormone, constructed on the 29-amino-acid fragment designated GRF(1-29). The name began as an internal development code during the 1990s and later spread through research supply catalogs and discussion forums. The molecule does not occur in nature; its sequence is engineered rather than isolated from tissue. Two related compounds are sold under this single label, and they differ by one appended chemical group that strongly influences how long the peptide remains in circulation.

The dividing feature between the two forms is a maleimide-based drug affinity complex, abbreviated DAC. In the DAC-bearing version, a linker attaches the peptide to serum albumin after administration, and that association slows removal from plasma. The version lacking DAC appears in catalogs as MOD GRF(1-29) or tetrasubstituted GRF(1-29). Because informal writing treats both as one item, comparisons drawn from such sources routinely blend measurements taken from two molecules with substantially different behavior.

Four amino acid substitutions separate the modified backbone from the parent GRF(1-29) sequence. These changes reduce recognition by dipeptidyl peptidase IV and related proteases, extending the interval before degradation. Development work in this area sought longer-acting GHRH analogs for endocrine investigation. Published descriptions treat the substitution set as a defining property of the core sequence, while the albumin-binding linker is described separately as an optional addition to that same backbone.

Handling, Stability and Analysis

Lyophilised powder is the usual supplied form. The material is hygroscopic, so vials are typically equilibrated to room temperature before opening in order to prevent condensation on the contents. Long-term storage is generally described at minus twenty degrees Celsius or colder, protected from light and moisture. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of soluble material. A reconstituted solution is considerably less stable than the dry powder and is normally kept refrigerated for short periods only.

Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography combined with mass spectrometry. The chromatographic separation resolves the target peptide from truncation products and from species carrying oxidised residues, while mass measurement confirms the expected molecular mass. Because the two common variants differ by roughly 280 daltons, a mass determination distinguishes them unambiguously. Purity is often quoted as a percentage of total peak area, although that figure depends on the detection wavelength and the integration method applied.

Reported half-lives differ widely between the two variants and between species. Values for the albumin-binding form are usually expressed in days, while the unconjugated form is measured in minutes to a few hours. Sampling schedules, assay sensitivity, and route of administration all influence the numbers, which limits direct comparison across studies. Whether sustained receptor occupancy produces different downstream effects from pulsatile stimulation remains an open question in the published work. Claims about relative potency should therefore be read alongside the specific study design that produced them.

Cjc-1295 at a glance

PropertyValueNotes
Molecular classSynthetic peptideAnalog of growth hormone-releasing hormone
Chain length29 amino acidsBased on the GRF(1-29) fragment
AppearanceWhite to off-white lyophilized powderCommon research supply form
SolubilitySoluble in water and aqueous buffersPowder requires reconstitution before use
Typical storage−20 °C or belowKept away from light and moisture

CJC-1295 Background and Mechanism

The peptide binds GHRH receptors on somatotroph cells within the anterior pituitary, triggering a signalling cascade that increases growth hormone secretion. Its improved resistance to dipeptidyl peptidase IV degradation distinguishes it from the parent hormone. In the DAC-bearing version, a maleimide group reacts with a cysteine residue on serum albumin, forming a covalent bond that keeps the peptide in circulation far longer. That albumin attachment is the central design feature separating the two research variants.

Pharmacokinetic behaviour differs sharply between the two forms. The DAC-bearing peptide shows an extended circulation time measured in days, whereas the version without the complex is cleared within roughly half an hour. This gap shapes how researchers design dosing schedules in animal models. Whether the prolonged presence of the DAC form produces effects meaningfully different from the short-acting variant remains an open question, since comparative human data are scarce.

Related pages on this site

Structure And Receptor Pharmacology

Receptor level activity follows the canonical GHRH pathway. The peptide binds the GHRH receptor, a class B G protein coupled receptor on somatotroph cells of the anterior pituitary. Binding raises intracellular cyclic AMP, which promotes calcium entry and the release of growth hormone into the bloodstream. Because the molecule acts at the same receptor as the endogenous hormone, its effect is superimposed on the natural pulsatile rhythm rather than replacing it. Whether sustained receptor occupation leads to desensitization is not fully settled.

CJC-1295 belongs to a class of synthetic peptides modeled on growth hormone releasing hormone, a forty-four amino acid signal produced by the hypothalamus. The compound is built from the first twenty-nine residues of the natural sequence, with four substitutions introduced at positions 2, 8, 15 and 27. These changes were designed to slow enzymatic breakdown while preserving receptor activation. The result is a peptide that is shorter than native GHRH and considerably more resistant to ordinary clearance pathways in circulation.

Two related forms appear under the CJC-1295 name. The simpler analogue, commonly written as modified GRF(1-29), carries the four substitutions but no additional conjugation. The second form attaches a maleimidopropionic acid linker to a lysine residue, a modification frequently called the drug affinity complex. That linker reacts with the free thiol on serum albumin to form a covalent bond. Because albumin has a long residence time in blood, the conjugated peptide stays in circulation far longer than the unconjugated analogue.

Further detail

== Crystal structure == Serotonin crystallizes in P212121 chiral space group forming different hydrogen-bonding interactions between serotonin molecules via N-H...O and O-H...N intermolecular bonds. Serotonin also forms several salts, including pharmaceutical formulation of serotonin adipate.

=== Fecal transplants === In humans, fecal transplants (or stool transplant) is the process of transplantation of fecal bacteria from a healthy individual into a recipient who has a certain disease, such as irritable bowel syndrome. The resulting inoculation of healthy gut flora can sometimes improve the physiology of the recipient gut. Fecal bacteriotherapy—also known as a fecal transplant—is a medical procedure wherein fecal bacteria are transplanted from a healthy individual into a patient. Recent research indicates that this may be a valuable method to re-establish normal gut cultures that have been destroyed through the use of antibiotics or some other medical treatments.

The second modification required is the addition of an azide to the N-terminus. Unlike the addition of the alkyne this can be done on the whole peptide, or solely on the N-terminal residue which is added to the rest of the oligopeptide by solid-phase peptide synthesis. The addition of the azide occurs by Cu(II)-catalyzed diazo transfer.

Sources: en.wikipedia.org

Supporting material

==== Fistulizing disease ==== Infliximab was first used for closure of fistulae in Crohn's disease in 1999. In a 94-patient, phase II clinical trial, the researchers showed infliximab was effective in closing fistulae between the skin and bowel in 56–68% of patients. A large, 296-patient Phase III clinical trial called the ACCENT 2 trial showed infliximab was additionally beneficial in maintaining closure of fistulae, with almost two-thirds of all patients treated with the three initial doses of infliximab having a fistula response after 14 weeks, and 36% of patients maintaining closure of fistulae after a year, compared with 19% who received placebo therapy. This final trial resulted in the FDA approval of the drug to treat fistulizing disease.

Abdul Haleem's accomplice, Muhammad Ridzuan bin Md Ali, on the other hand, was sentenced to death for drug trafficking and later hanged on 19 May 2017. After the changes to the law, the first executions to take place were those of drug traffickers Tang Hai Liang and Foong Chee Peng on 18 July 2014, after their sentences were finalized and their refusal to further appeal against their sentences.

=== India === Specialty training in India is overseen by the National Medical Commission (formerly Medical Council of India), responsible for recognition of post graduate training and by the National Board of Examinations. Education of Ayurveda in overseen by Central Council of Indian Medicine (CCIM), the council conducts UG and PG courses all over India, while Central Council of Homoeopathy does the same in the field of Homeopathy. Specialization and superspecialization in medicine and surgery are pursued after completing MBBS, for which higher medical (MD, DM) and surgical (MS, MCh) degrees are awarded. The following medical and surgical specialties and superspecialties are recognized by the National Medical Commission (formerly Medical Council of India) and National Board of Examinations in Medical Sciences:

=== Peptide synthesis/ACTH === The first chemical synthesis of an active peptide hormone, the nine amino acid cyclic peptide, oxytocin, was achieved in 1954 by du Vigneaud for which he was awarded the Nobel Prize. At the same time, the isolation and structure determination of the anterior pituitary hormone, ACTH, was being pursued in three laboratories. The peptide was eventually determined to be 39 amino acids in length, however enzymatic and mild acid cleavage suggested that a structure comprising only the first 24 amino acids had full biological activity. It was apparent from the outset that ACTH contained the amino acid Arginine and thus methods had to be developed for the incorporation of this basic amino acid into peptides. Hofmann and his group set about this task. Their efforts led to the synthesis of the melanocyte stimulating hormone, β-MSH, which corresponds to the first 13 amino acids of ACTH and to the synthesis of a fully active ACTH peptide corresponding to the amino acid sequence of the first 23 amino acids. In the course of the peptide synthetic work on ACTH, a novel chain cleavage was observed at an acyl-proline linkage while removing protecting groups using metallic sodium in liquid ammonia. This unexpected reaction has subsequently proved useful in special analytical cases.

Sources: en.wikipedia.org

Frequently asked questions

Does this compound occur naturally in the body?

No. It is a laboratory-synthesized analog built on a fragment of the natural hormone. The natural peptide is shorter-lived and lacks the stabilizing substitutions found in the synthetic version.

What does the abbreviation DAC refer to?

DAC stands for drug affinity complex, a chemical group that binds the peptide to serum albumin. The binding slows clearance and lengthens the time the molecule stays in plasma compared with the unmodified analog.

Why do different sources report different half-lives for the same name?

Because two distinct molecules are discussed under one informal label. The albumin-binding version clears over several days, while the form without that group clears within roughly half an hour. Mixing results from both creates inconsistent figures.

Why is mass spectrometry used alongside chromatography?

Chromatography reports how much material elutes as a single peak but does not confirm what that material is. Mass spectrometry supplies the molecular mass, which is characteristic of a given sequence and its modifications. Together the two methods support both a purity figure and an identity claim.

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