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Background And Molecular Design — Hands-On Walkthrough

By Editorial Desk · published 2025-08-03 · last reviewed 2025-09-03 · Blog

Everything below concerns Albumin binding. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.

Last reviewed on 2025-09-03. Where a claim depends on a specific study, the study is described rather than over-claimed.

Background and Molecular Design

CJC-1295 belongs to a family of synthetic peptides modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound is built from the first twenty-nine amino acids of the natural human sequence, a fragment that retains full receptor binding capacity. Native growth hormone-releasing hormone is degraded quickly in circulation, so the fragment alone has limited practical value. Early work therefore focused on chemical modifications that preserve receptor binding while slowing enzymatic breakdown. The result is a molecule described in the literature as a long-acting analog of the natural hormone.

Two forms circulate under the CJC-1295 name, and they differ by a single appended group. The version without a drug affinity complex carries four substitutions along the peptide chain, including a D-alanine near the amino terminus and replacements at three other positions. These changes block the enzyme dipeptidyl peptidase IV and remove a methionine residue that is prone to oxidation. The modified fragment is frequently labeled MOD GRF 1-29. Naming conventions are inconsistent across informal sources, which is a common source of confusion.

The second form adds a maleimide-bearing linker to the lysine at the carboxyl end. This group reacts with cysteine-34 on circulating serum albumin, forming a covalent bond that keeps the peptide in the bloodstream for far longer. ConjuChem developed the molecule as a way to extend the action of a peptide without frequent administration. The albumin attachment is the defining structural feature of the drug affinity complex version. Whether continuous exposure produces effects distinct from shorter pulses remains an unresolved research question.

Compound Identity and Development History

CJC-1295 is a synthetic peptide built as a long-acting analogue of growth hormone-releasing hormone. Its backbone matches the first twenty-nine residues of the natural human hormone, with four amino acid substitutions added to slow enzymatic breakdown. A reactive maleimide group, commonly termed the drug affinity complex, allows the peptide to attach to circulating albumin after administration. That albumin attachment keeps the molecule in the bloodstream for an extended period instead of being cleared within minutes.

The compound emerged from work at a Canadian biotechnology firm in the early 2000s. Early human studies examined its effect on growth hormone and insulin-like growth factor 1 in healthy volunteers and in people with HIV-associated fat redistribution. Reports described sustained increases in both markers after a single injection. Development did not advance to regulatory approval, and the clinical programme was later discontinued. The molecule is now encountered mainly as a research chemical rather than a marketed medicine.

Cjc-1295 at a glance

PropertyValueNotes
Molecular formulaC152H252N44O42Cited for the form without the drug affinity complex
Molecular weightAbout 3368 DaReported value for modified GRF(1-29)
AppearanceWhite to off-white powderLyophilised solid as usually supplied
SolubilitySoluble in water and polar solventsClarity depends on purity and salt content
Typical storage-20 C or below, dryProtect from light and repeated warming cycles

CJC-1295 Structure And Mechanism

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.

The drug affinity complex is a maleimidopropionic acid group attached to a lysine side chain. It reacts with the free thiol of cysteine-34 on circulating albumin, forming a covalent bond. This conjugation keeps the peptide in the bloodstream and shields it from rapid renal filtration and proteolysis. Reported circulation half-lives for the albumin-bound form fall in the range of roughly six to nine days in early human studies.

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Background and Naming Conventions

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.

Albumin Binding and Duration of Action

The distinguishing feature of the DAC form is a maleimide-containing group that reacts with the free thiol of cysteine-34 on human serum albumin. This reaction forms a covalent bond without enzymatic assistance, and it takes place after the peptide enters the bloodstream. Because albumin is abundant and long-lived, the attached peptide is carried through circulation far longer than an unmodified fragment would survive. The chemistry is a deliberate pharmacokinetic strategy rather than a change to receptor activity.

Enzymatic protection is a separate mechanism from plasma protein binding. The four substitutions in the backbone reduce recognition by dipeptidyl peptidase IV, which normally cleaves the natural hormone within minutes. Without the reactive group, this resistance still yields only a short window of activity, generally reported in the range of tens of minutes. With it, reported half-lives in early human work extended to several days. The size of that gap is the main practical distinction between the two materials.

Both forms act at the pituitary receptor for growth hormone-releasing hormone and increase growth hormone output, which in turn raises insulin-like growth factor 1. A long-acting analog produces sustained rather than pulsatile stimulation, and the physiological consequences of that pattern are not fully settled. Published human data on the extended form remain limited, and much of what circulates in discussion traces to early company reports rather than independent replication. How sustained exposure affects normal feedback remains an open question.

Background from the literature

=== Foot surgeries === Generally, foot surgery is usually reserved for patients with a walking or ambulatory potential. Foot surgery may also be indicated to assist brace and orthosis fitting and hence promote supported standing. The most common foot deformity in arthrogryposis is club feet or talipes equinovarus. In the early years of life the serial casting according to the Ponseti method usually yields good results. The Ponseti method can also be used as a first line treatment in older and more resistant cases. In such severe and neglected cases bony surgery in the form of foot osteotomies and arthrodesis is usually indicated. It is usually accompanied by soft tissue surgery in the form of release of contracted tendon and capsular structures. In older patients near skeletal maturity joint fusion or arthrodesis may be indicated as well. Less frequent patients with arthrogryposis may develop congenital vertical talus also known as rocker bottom foot. Similarly, congenital vertical talus is classically managed by serial casting according to the reversed Ponseti method. Resistant or recurrent cases may be offered an extensive soft tissue release. However this is fraught with risk of foot stiffness and pain in the long term. Talectomy or excision of the talus to give room for creation of plantigrade foot has been practiced. Naviculectomy or midtarsal resection arthroplasty represents a less invasive option with satisfactory short-term results.

=== International growth: 2010s === The market for electronic cigarettes rose rapidly during the early 2010s and it started gaining attention in mainstream media. International tobacco companies dismissed e-cigarettes as a fad at first, but, recognizing a potential new market sector that could make smoking obsolete, they began to produce and market their own brands of e-cigarettes and acquire existing e-cigarette companies. Tobacco companies bought established e-cigarette companies. Blu eCigs, a prominent US e-cigarette manufacturer, was acquired by Lorillard Inc. for $135 million in April 2012. Japan Tobacco invested in Ploom. British American Tobacco was the first tobacco business to sell e-cigarettes in the UK and launched the e-cigarette Vype in July 2013. Imperial Tobacco's Fontem Ventures acquired the intellectual property owned by Hon Lik through Dragonite International Limited for $US 75 million in 2013 and launched Puritane in partnership with Boots UK. On 1 October 2013 Lorillard Inc. acquired another e-cigarette company, this time the UK based company SKYCIG. SKY was rebranded as blu.

13 November The story of the 1968 My Lai Massacre was revealed to the public by freelance American investigative reporter Seymour Hersh, who was contributing to the Dispatch News Service. The New York Times published a similar report at the same time.

Sources: en.wikipedia.org

Further detail

Tyrannosaurus, like most dinosaurs, was long thought to have an ectothermic ("cold-blooded") reptilian metabolism. The idea of dinosaur ectothermy was challenged by scientists like Robert T. Bakker and John Ostrom in the early years of the "dinosaur renaissance", beginning in the late 1960s. T. rex itself was claimed to have been endothermic ("warm-blooded"), implying a very active lifestyle. Since then, several paleontologists have sought to determine the ability of Tyrannosaurus to regulate its body temperature. Histological evidence of high growth rates in young T. rex, comparable to those of mammals and birds, may support the hypothesis of a high metabolism. Growth curves indicate that, as in mammals and birds, T. rex growth was limited mostly to immature animals, rather than the indeterminate growth seen in most other vertebrates. Oxygen isotope ratios in fossilized bone are sometimes used to determine the temperature at which the bone was deposited, as the ratio between certain isotopes correlates with temperature. In one specimen, the isotope ratios in bones from different parts of the body indicated a temperature difference of no more than 4 to 5 °C (7 to 9 °F) between the vertebrae of the torso and the tibia of the lower leg. This small temperature range between the body core and the extremities was claimed by paleontologist Reese Barrick and geochemist William Showers to indicate that T. rex maintained a constant internal body temperature (homeothermy) and that it enjoyed a metabolism somewhere between ectothermic reptiles and endothermic mammals.

=== Earliest recorded cases === OI has been identified in an ancient Egyptian infant mummified in around 1000 BC, originally dismissed by archaeologists as containing the remains of a monkey. The Norse king Ivar the Boneless, who lived c. 800 CE, is speculated to have had OI as well. Nicolas de Malebranche is often credited as being the first person to describe the physical characteristics of OI in his 1688 book The Search after Truth, in which he describes a man who has had his "bones broken in the places a murderer's would be" all his life. His confident description of the pathology of the disorder, however, which creates what he termed «enfants monstrueux» ("monstrous children"), is scientifically void—he wrote that it was due to the mother's antepartum viewership of a public execution by breaking wheel. The earliest modern scientific studies of OI began in 1788 by Olof Jakob Ekman, who described the condition, which he termed "osteomalacia congenital", in his doctoral thesis and mentioned cases of it going back to 1678, all in the same family, through three generations. Ekman's description of the condition mentioned dwarfism, bone fragility, and bowing of the long bones. In 1831, Edmund Axmann gave a detailed description of it in himself and his two brothers, being the first to mention blue sclerae as a characteristic sign of OI. Jean Lobstein first described the mild form of the condition, today known as type I, in 1833, calling it "osteopsathyrosis idiopathica".

Hide glue is made from animal hide (animal skin) and is often used in woodworking. It may be supplied as granules, flakes, or flat sheets, which have an indefinite shelf life if kept dry. It is dissolved in water, heated and applied warm, typically around 60 °C (140 °F). Warmer temperatures quickly destroy the strength of hide glue. Commercial glue pots, simple water baths or double boilers may be used to keep the glue hot while in use. As hide glue cools, it gels quickly. At room temperature, prepared hide glue has the consistency of stiff gelatin, which is in fact a similar composition. Gelled hide glue does not have significant strength, so it is vital to apply the glue, fit the pieces, and hold them steady before the glue temperature drops much below 50 °C (120 °F). All glues have an open time, the amount of time the glue remains liquid and workable. Joining parts after the open time is expired results in a weak bond. Hide glue's open time is usually a minute or less. In practice, this often means having to heat the pieces to be glued, and gluing in a very warm room, though these steps can be dispensed with if the glue and clamp operation can be carried out quickly. Where hide glue is in occasional use, excess glue may be held in a freezer, to prevent spoilage from the growth of microorganisms. Hide glue has some gap filling properties, although modern gap-filling adhesives, such as epoxy resin, are better in this regard. Hide glue that is liquid at room temperature is also possible through the addition of urea.

Sources: en.wikipedia.org

Frequently asked questions

What is CJC-1295?

It is a synthetic peptide analogue of growth hormone-releasing hormone. Four substitutions in its sequence make it more resistant to enzymatic degradation than the natural hormone. In the version carrying a drug affinity complex, the peptide binds albumin and remains in circulation for days.

Is CJC-1295 an approved medicine?

No regulatory agency has approved CJC-1295 for clinical use. Human trials were conducted in the 2000s, but the development programme was discontinued before any marketing application succeeded. Material sold today is offered as a research chemical, and its purity depends on the supplier.

How does it differ from sermorelin?

Sermorelin is an unmodified fragment of growth hormone-releasing hormone and is cleared quickly. CJC-1295 contains substitutions that resist breakdown, and the form with a drug affinity complex persists much longer. Both act at the same receptor but differ substantially in duration of action.

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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