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Molecular Background And Naming — Quick Reference

By Editorial Desk · published 2025-10-19 · last reviewed 2025-11-30 · Faq

This is a working overview of albumin conjugate, written for readers who want more than a one-paragraph summary but less than a textbook.

This page was last updated on 2025-11-30 and is reviewed periodically as new material appears.

Molecular Background and Naming

The peptide backbone includes a D-alanine at position two, which resists cleavage by dipeptidyl peptidase IV, and several other substitutions that reduce degradation. Its molecular weight is roughly 3.4 kDa without the linker and about 3.6 kDa with it. The molecule is water soluble and is normally supplied as a lyophilized powder. Precise sequence and mass values depend on which variant is described, so technical documents usually state the exact form being referenced.

CJC-1295 is a synthetic peptide designed as a long-acting analogue of growth hormone-releasing hormone (GHRH). Its structure derives from the first 29 amino acids of native GHRH, a fragment often called GRF(1-29). Four substitutions were introduced to slow enzymatic breakdown and extend activity relative to the natural sequence. The compound was developed by ConjuChem as part of a broader effort to improve the pharmacokinetic profile of peptide hormones. It is studied in laboratory and clinical research settings rather than appearing as a naturally occurring substance.

CJC-1295 Structure And Mechanism

Binding to GHRH receptors on pituitary somatotroph cells triggers cyclic AMP signaling and stimulates growth hormone synthesis and release. Because the peptide acts upstream of the pituitary, effects are mediated through endogenous growth hormone rather than direct receptor activation in peripheral tissues. Increases in insulin-like growth factor 1 are generally described as a downstream consequence. Most published human exposure data come from small early-stage studies, and the clinical significance of the pharmacokinetic profile remains incompletely characterized.

CJC-1295 is a synthetic analogue of growth hormone-releasing hormone, built on the 29-amino-acid GHRH(1-29) fragment. Four substitutions distinguish it from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes reduce enzymatic cleavage and extend the peptide's persistence in circulation. The compound is discussed in two forms, one carrying a drug affinity complex and one without it.

Cjc-1295 at a glance

PropertyValueNotes
Molecular weight (no linker)~3.37 kDaCalculated from peptide sequence
Molecular weight (with linker)~3.65 kDaIncludes albumin-binding moiety
AppearanceWhite to off-white powderTypically lyophilized
SolubilitySoluble in waterAlso dissolves in aqueous buffers
Common synonymsModified GRF(1-29), DAC:GRFUsage varies by source

Receptor Action and Pharmacokinetics

The attached maleimide group explains the unusual duration of the DAC version. After injection it reacts with the thiol of cysteine-34 on serum albumin, forming a stable covalent bond. The resulting conjugate is too large for rapid kidney filtration and is shielded from many peptidases. Reported half-lives for this form reach several days, whereas the version without the group is cleared in roughly half an hour. That gap is the main pharmacological difference between the two.

Downstream of growth hormone, the liver and other tissues increase production of insulin-like growth factor 1, a mediator of many growth-promoting effects. Studies have documented elevated levels of both hormones after dosing, and the rise from the long-acting form persists longer than that produced by shorter-acting analogues. What remains unclear is whether sustained elevation of these markers translates into meaningful clinical benefit, and whether prolonged exposure carries risks that short trials could not detect.

CJC-1295 acts at the growth hormone-releasing hormone receptor, a G-protein-coupled receptor found on somatotroph cells in the anterior pituitary. Binding triggers a rise in cyclic AMP and calcium entry, which promotes release of stored growth hormone. Because the peptide mimics the body's own releasing hormone, it amplifies existing secretory pulses rather than driving continuous output. The size of the response therefore depends partly on the subject's own hormonal rhythm and feedback state.

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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.

Mechanism and Pharmacokinetics

The albumin-binding version stays in circulation for days, because covalent attachment to serum albumin shields the peptide from rapid filtration and degradation. Reported half-lives for this form fall in the range of several days. The version without the linker is cleared in minutes, with estimates often near thirty minutes in animal work. These figures come from small studies and vary with assay method, species, and route, so they are best read as approximate rather than fixed constants.

Studies in this area generally track growth hormone pulses, insulin-like growth factor 1 concentrations, and occasionally body composition endpoints. Most published human data come from early, small trials, and questions about long-term effects remain open. Whether repeated exposure alters pituitary responsiveness over time is not settled. Analytical work relies on immunoassays for the hormones and on mass spectrometry for the peptide itself, because the two measurements answer different questions.

Further detail

===== Generic drug scandal ===== In 1989, a major scandal erupted involving the procedures used by the FDA to approve generic drugs for sale to the public. Charges of corruption in generic drug approval first emerged in 1988 during the course of an extensive congressional investigation into the FDA. The oversight subcommittee of the United States House Energy and Commerce Committee resulted from a complaint brought against the FDA by Mylan Laboratories Inc. of Pittsburgh. When its application to manufacture generics was subjected to repeated delays by the FDA, Mylan, convinced that it was being discriminated against, soon began its own private investigation of the agency in 1987. Mylan eventually filed suit against two former FDA employees and four drug-manufacturing companies, charging that corruption within the federal agency resulted in racketeering and violations of antitrust law. "The order in which new generic drugs were approved was set by the FDA employees even before drug manufacturers submitted applications," and, according to Mylan, this illegal procedure was followed to give preferential treatment to certain companies. During the summer of 1989, three FDA officials (Charles Y. Chang, David J. Brancat, and Walter Kletch) pleaded guilty to criminal charges of accepting bribes from generic drug makers, and two companies (Par Pharmaceutical and its subsidiary Quad Pharmaceuticals) pleaded guilty to giving bribes. Furthermore, it was discovered that several manufacturers had falsified data submitted in seeking FDA authorization to market certain generic drugs.

== Analysis == A wide range of instrumental techniques are employed in nuclear forensics. Radiometric counting techniques are useful when determining decay products of species with short half-lives. However, for longer half-lives, inorganic mass spec is a powerful means of carrying out elemental analysis and determining isotopic relationships. Microscopy approaches can also be useful in characterization of a nuclear material.

Liquefied gases, such as liquid nitrogen and liquid helium, are used in many cryogenic applications. Liquid nitrogen is the most commonly used element in cryogenics and is legally purchasable around the world. Liquid helium is also commonly used and allows for the lowest attainable temperatures to be reached. These liquids may be stored in Dewar flasks, which are double-walled containers with a high vacuum between the walls to reduce heat transfer into the liquid. Typical laboratory Dewar flasks are spherical, made of glass and protected in a metal outer container. Dewar flasks for extremely cold liquids such as liquid helium have another double-walled container filled with liquid nitrogen. Dewar flasks are named after their inventor, James Dewar, the man who first liquefied hydrogen. Thermos bottles are smaller vacuum flasks fitted in a protective casing. Cryogenic barcode labels are used to mark Dewar flasks containing these liquids, and will not frost over down to −195 degrees Celsius. Cryogenic transfer pumps are the pumps used on LNG piers to transfer liquefied natural gas from LNG carriers to LNG storage tanks, as are cryogenic valves.

population, comparable to White Americans. In 2018, the opioid crisis continued to disproportionately affect non-Hispanic Whites and Native Americans with the National Institutes of Health (NIH) reporting a rise in opioid morbidity and opioid related fatalities. During 2019–2020, non-Hispanic American Indian/Alaska Native and Black individuals experienced the greatest increases in drug overdose mortality rates. Additionally, American Indian/Alaska Native and Black individuals had the highest opioid overdose rate 2020 and 2021. The percentage of individuals with documentation of prior treatment for substance use disorders was low, especially among Black individuals, at 8.3%. Overall, Hispanics, Native Hawaiians, and Asians experienced the lowest rate of overdose deaths. Though previous statistics show that non-Hispanic White Americans have been affected by the opioid epidemic more than other racial/ethnic groups in the United States, recent statistics show that Black Americans are experiencing a sharper increase in opioid-overdose deaths. The annual percentage change of opioid overdose deaths among Black Americans increased to 26.16 from 2012 to 2018 while White Americans only experienced an 18.96 increase from 2013 to 2016 and even had an annual percentage change decrease to 5.07 from 2016 to 2018. The challenges that non-Hispanic Black Americans face have a disparate impact on the rates of opioid-overdose related deaths when compared to non-Hispanic White Americans who have not dealt with the challenges of structural racism.

== Genetics == Gilbert syndrome is a phenotypic effect, mostly associated with increased blood bilirubin levels, but also sometimes characterized by mild jaundice due to increased unconjugated bilirubin, that arises from several different genotypic variants of the gene for the enzyme responsible for changing bilirubin to the conjugated form. Gilbert's syndrome is characterized by a 70–80% reduction in the glucuronidation activity of the enzyme UGT1A1. The UGT1A1 gene is located on human chromosome 2. More than 100 polymorphisms of the UGT1A1 gene are known, designated as UGT1A1*n (where n is the general chronological order of discovery), either of the gene itself or of its promoter region. UGT1A1 is associated with a TATA box promoter region; this region most commonly contains the genetic sequence A(TA)6TAA; this variant accounts for about 50% of alleles in many populations. However, several allelic polymorphic variants of this region occur, the most common of which results from adding another dinucleotide repeat TA to the promoter region, resulting in A(TA)7TAA, which is called UGT1A1*28; this common variant accounts for about 40% of alleles in some populations, but is seen less often, around 3% of alleles, in Southeast and East Asian people and Pacific Islanders. In most populations, Gilbert syndrome is most commonly associated with homozygous A(TA)7TAA alleles. In 94% of GS cases, two other glucuronosyltransferase enzymes, UGT1A6 (rendered 50% inactive) and UGT1A7 (rendered 83% ineffective), are also affected.

Sources: en.wikipedia.org

Supporting material

== Honors and awards == Meldal was awarded the 2022 Nobel Prize in Chemistry, jointly with Carolyn R. Bertozzi and Karl Barry Sharpless, "for the development of click chemistry and bioorthogonal chemistry".

== History == Multiple epiphyseal dysplasia was described separately by Seved Ribbing and Harold Arthur Thomas Fairbank in the 1930s. In 1994, Ralph Oehlmann's group mapped MED to the peri-centromeric region of chromosome 19, using genetic linkage analysis. Michael Briggs' group mapped PSACH to the same area. COMP gene was firstly linked to MED and PSACH in 1995. In 1995, the group led by Knowlton did a "high-resolution genetic and physical mapping of multiple epiphyseal dysplasia and pseudoachondroplasia mutations at chromosome 19p13.1-p12." Research on COMP led to mouse models of the pathology of MED. In 2002, Svensson's group generated a COMP-null mouse to study the COMP protein in vivo. These mice showed no anatomical, histological, or even ultrastructural abnormalities and none of the clinical signs of PSACH or MED. Lack of COMP was not compensated for by any other protein in the thrombospondin family. This study confirmed that the disease is not caused by reduced expression of COMP. In 2007, Piròg-Garcia's group generated another mouse model carrying a mutation previously found in a human patient. With this new model, they were able to demonstrate that reduced cell proliferation and increased apoptosis are significant pathological mechanisms involved in MED and PSACH. In 2010, this mouse model allowed a new insight into myopathy and tendinopathy, which are often associated with PSACH and MED. These patients show increased skeletal muscle stress, as indicated by the increase in myofibers with central nuclei.

== Adverse effects == A 2011 Cochrane review found that, compared with other antidepressants, it is more likely to cause weight gain and sleepiness, but it is less likely to cause tremors than tricyclic antidepressants, and less likely to cause nausea and sexual dysfunction than selective serotonin reuptake inhibitors. Very common (≥10% incidence) adverse effects include constipation, dry mouth, sleepiness, increased appetite (17%) and weight gain (>7% increase in <50% of children). Common (1–10% incidence) adverse effects include weakness, confusion, dizziness, fasciculations (muscle twitches), peripheral edema (swelling, usually of the lower limbs), and abnormal lab results like elevated transaminases, elevated serum triglycerides, and elevated total cholesterol. Mirtazapine is not considered to have a risk of many of the side effects often associated with other antidepressants like the selective serotonin reuptake inhibitors and may improve certain ones when taken in conjunction with them. (Those adverse effects include decreased appetite, weight loss, insomnia, nausea and vomiting, diarrhea, urinary retention, increased body temperature, excessive sweating, pupil dilation and sexual dysfunction.) In general, some antidepressants, especially selective serotonin reuptake inhibitors, can paradoxically worsen some peoples' depression or anxiety or cause suicidal ideation.

On March 7, 2025, Duterte left for Hong Kong alongside Honeylet Avanceña, his daughter Veronica and his entourage. Although his lawyer Salvador Panelo said that his purpose of travel was to attend a KOJC-organized campaign sortie for Partido Demokratiko Pilipino among overseas Filipino workers, his departure coincided with reports that the release of an arrest warrant for Duterte from the International Criminal Court (ICC) was imminent. Others who attended the event include Duterte's daughter, Vice President Sara Duterte, Senators Ronald dela Rosa and Bong Go, and senatorial candidates Rodante Marcoleta and Vic Rodriguez. On March 11, 2025, upon his return from Hong Kong on a commercial flight, Duterte was arrested at Ninoy Aquino International Airport for crimes against humanity of murder, torture, and rape. The warrant was issued by the ICC, but coursed through Interpol. A top official of the Marcos administration earlier said that the government would honor its commitments to Interpol if an arrest warrant was issued, despite its policy of not cooperating with the ICC. Duterte questioned the warrant's legitimacy, asserting that the arrest did not follow standard procedures and that any prosecution should occur within the Philippines. His supporters rallied in major cities condemning the arrest, while activists hailed the arrest as a pivotal moment for justice. He was soon surrendered to the ICC in The Hague, Netherlands, where he was being held as of 11 March 2025.

Sources: en.wikipedia.org

Frequently asked questions

Is CJC-1295 a natural hormone?

No. It is a synthetic analogue modeled on the first 29 residues of human GHRH. The substitutions and any linker are laboratory modifications rather than features of the endogenous peptide.

Why do two versions share one name?

Early development used the albumin-binding form, and a shorter variant was later discussed under the same label. Because the two differ in half-life and handling, ambiguity arises whenever a source omits the variant designation.

What is the relationship to GRF(1-29)?

The compound derives from that fragment but is not identical to it. The parent fragment lacks the stabilizing substitutions, so its degradation rate and duration of action differ noticeably.

How does CJC-1295 differ from modified GRF(1-29)?

The two share the same 29-amino-acid backbone. CJC-1295 carries an additional albumin-binding moiety that markedly extends its residence time in circulation, while the form without that moiety clears faster. Literature sometimes applies the name loosely to either variant.

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