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Molecular Background And Naming — Explained

By Editorial Desk · published 2026-05-29 · last reviewed 2026-07-13 · Guide

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

Reviewed 2026-07-13. Anything still debated is marked as such rather than presented as settled.

Molecular Background and Naming

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.

Two related forms circulate in technical discussion under the same family name. The original version carries a drug affinity complex (DAC) that binds covalently to serum albumin after administration, and this linkage substantially extends circulation time. A second form, frequently written as modified GRF(1-29) or CJC-1295 without DAC, lacks that linker and clears much faster. The naming is a frequent source of confusion because the shorthand CJC-1295 can refer to either form depending on the source. Reports sometimes fail to specify which variant was studied.

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 Structure And Mechanism

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.

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

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.

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.

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Structure And Receptor Pharmacology

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.

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.

Further detail

=== In Anthropology === An anthropological lens challenges the idea that drug use is a universal problem, instead suggesting that perceptions of substance use and addiction depend on social, historical, political and cultural context. Drug policy and public responses vary globally, with disparities between the United Kingdom, Australia, and the United States. In the UK, drug use has become framed on crime prevention and coercion of drug users, demonstrating that definitions of harm are culturally and politically bound, questioning who health policies benefit. The USA has focused on the criminalisation of drug use, framing drug users as “morally reprehensible” and “deviant criminals”, shaping drug use as an issue of crime and social order. Australia’s 1985 adoption of harm minimisation strategies highlights that policy can shift alongside historical circumstances. The HIV/AIDS epidemic prompted a focus on safe injecting, rather than eradicating drug use. Maher and Dixon’s ethnographic research revealed that “attempts to suppress or control” drug use can shape how it is carried out, demonstrating that drug policy can shape experiences of harm. These cases corroborate Singer’s idea that drug use must be understood in its context, which challenges the narrative that drug-related harm is solely the users’ responsibility.

==== IR spectroscopy ==== One case study investigated the formation of gaseous intermediates in the decomposition of CCl4 in the presence of steam over La2O3 using Fourier-transform infrared spectroscopy. This experiment produced useful information about the reaction mechanism, active site orientation, and about which species compete for the active site.

== Historical precedents == High quality, portable, dense energy foods have long been a part of food preservation and long-distance travel. In indigenous North America, Pemmican provided long-term storage and preservation of food in a high density patty. In Europe, classical Greek soldiers made dishes like Pastelli, a high density honey and sesame seed bar that can transport and endure long distances. In India, Chikki is a dessert dish that concentrates sugar and nuts. In Aztec food traditions, Amaranth seed is combined with honey to create seed cakes, which are served in modern Mexico as alegría.

As of 2023, one dose costs $8 for users in San Francisco. It is pure white, odorless and flavorless. The potency of fentanyl has led to the mistaken belief that exposure to fentanyl by touch can cause an overdose, a myth that has been repeated by media outlets and even government publications. As a result, the Drug Enforcement Administration has recommended that officers not field test drugs if fentanyl is suspected, but instead collect and send samples to a laboratory for analysis. "Exposure via inhalation or skin absorption can be deadly," they state. However, the American College of Medical Toxicity and the American Academy of Clinical Toxicology stated that, as of 2017, they were not aware of "emergency responders developing signs or symptoms consistent with opioid toxicity from incidental contact with opioids.". A 2021 article in the journal Health & Justice reported that "many of the reported fentanyl exposure incidents among police share the symptoms of a panic attack rather an opioid overdose," and a 2020 article from the Journal of Medical Toxicology stated that "the consensus of the scientific community remains that illness from unintentional exposures is extremely unlikely, because opioids are not efficiently absorbed through the skin and are unlikely to be carried in the air." According to the United States Drug Enforcement Agency in 2023, China continued to be the primary source of fentanyl being imported into the United States, killing over 100 Americans every day.

Sources: en.wikipedia.org

Supporting material

=== Approaches === In keeping with the performance and mass range of available mass spectrometers, two approaches are used for characterizing proteins. In the first, intact proteins are ionized by either of the two techniques described above, and then introduced to a mass analyzer. This approach is referred to as "top-down" strategy of protein analysis as it involves starting with the whole mass and then pulling it apart. The top-down approach however is mostly limited to low-throughput single-protein studies due to issues involved in handling whole proteins, their heterogeneity and the complexity of their analyses. In the second approach, referred to as the "bottom-up" MS, proteins are enzymatically digested into smaller peptides using a protease such as trypsin. Subsequently, these peptides are introduced into the mass spectrometer and identified by peptide mass fingerprinting or tandem mass spectrometry. Hence, this approach uses identification at the peptide level to infer the existence of proteins pieced back together with de novo repeat detection. The smaller and more uniform fragments are easier to analyze than intact proteins and can be also determined with high accuracy, this "bottom-up" approach is therefore the preferred method of studies in proteomics. A further approach that is beginning to be useful is the intermediate "middle-down" approach in which proteolytic peptides larger than the typical tryptic peptides are analyzed.

Although commercial refrigeration quickly progressed, it had limitations that prevented it from moving into the household. First, most refrigerators were far too large. Some of the commercial units being used in 1910 weighed between five and two hundred tons. Second, commercial refrigerators were expensive to produce, purchase, and maintain. Lastly, these refrigerators were unsafe. It was not uncommon for commercial refrigerators to catch fire, explode, or leak toxic gases. Refrigeration did not become a household technology until these three challenges were overcome.

The oral bioavailability of amphetamine varies with gastrointestinal pH; it is well absorbed from the gut, and bioavailability is typically 90%. Amphetamine is a weak base with a pKa of 9.9; consequently, when the pH is basic, more of the drug is in its lipid soluble free base form, and more is absorbed through the lipid-rich cell membranes of the gut epithelium. Conversely, an acidic pH means the drug is predominantly in a water-soluble cationic (salt) form, and less is absorbed. Between 16-20% of amphetamine circulating in the bloodstream is bound to plasma proteins. Following absorption, amphetamine readily distributes into most tissues in the body, with high concentrations occurring in cerebrospinal fluid and brain tissue. The half-lives of amphetamine enantiomers differ and vary with urine pH. At normal urine pH, the half-lives of dextroamphetamine and levoamphetamine are 9–11 hours and 11–14 hours, respectively. Highly acidic urine will reduce the enantiomer half-lives to 7 hours; highly alkaline urine will increase the half-lives up to 34 hours. The immediate-release and extended release variants of salts of both isomers reach peak plasma concentrations at 3 hours and 7 hours post-dose respectively. Amphetamine is eliminated via the kidneys, with 30–40% of the drug being excreted unchanged at normal urinary pH. When the urinary pH is basic, amphetamine is in its free base form, so less is excreted.

=== Algae-derived fibers (Alginate) === Alginate is a polysaccharide generated by brown algae, seaweed and specific species of bacteria. Bacteria and seaweed alginate differ in composition, modifications, molecular mass, viscoelasticity, and polydispersity. These unique qualities lead to a wide range of applications, including alginate's development of nanoparticles, nanotubes, microspheres, and microcapsules. Furthermore, the different types of sponges, hydrogels, foams, elastomers, and fibers that can be created with its growth and processing. It is widely employed in many facets of industrial fabrication. Alginate is commonly employed as a gelling agent, thickener, and stabilizer in a large variety of food products. Its ability to form gels under mild conditions makes it particularly useful for encapsulating flavors, vitamins, and other active ingredients. It is also used to develop hydrogels, printing pastes and sizing agents in biomedical, textile, cosmetic and agricultural industries. In the textile industry specifically, textile coatings, binders and finishes are the bulk of what alginate is used for, rather than formulating threads itself it reinforces the strength of other materials.

=== Hormone claim retracted === Although the original cytokine function of PBEF has not been confirmed to date, others have since reported or suggested a cytokine-like function for this protein. In particular, Nampt/PBEF was recently re-identified as a "new visceral fat-derived hormone" named visfatin. It is reported that visfatin is enriched in the visceral fat of both humans and mice and that its plasma levels increase during the development of obesity. Noteworthy is that visfatin is reported to exert insulin-mimetic effects in cultured cells and to lower plasma glucose levels in mice by binding to and activating the insulin receptor. However, the physiological relevance of visfatin is still in question because its plasma concentration is 40 to 100-fold lower than that of insulin despite having similar receptor-binding affinity. In addition, the ability of visfatin to bind and activate the insulin-receptor has yet to be confirmed by other groups. On 26 October 2007, A. Fukuhara (first author), I.Shimomura (senior author) and the other co-authors of the paper, who first described Visfatin as a visceral-fat derived hormone that acts by binding and activating the insulin receptor, retracted the entire paper at the suggestion of the editor of the journal 'Science' and recommendation of the Faculty Council of Osaka University Medical School after a report of the Committee for Research Integrity.

Sources: en.wikipedia.org

Supporting material

Somalia borders Djibouti to the northwest, Ethiopia to the west, the Gulf of Aden to the north, the Somali Sea and Guardafui Channel to the east, and Kenya to the southwest. With a land area of 637,657 square kilometres, Somalia's terrain consists mainly of plateaus, plains and highlands. Its coastline is more than 3,333 kilometres in length, the longest of mainland Africa. Its maritime claims include territorial waters of 200 nautical miles (370 km; 230 mi). Somalia has several islands and archipelagos on its coast, including the Bajuni Islands and the Saad ad-Din Archipelago. Strategically located at the mouth of the Bab el Mandeb gateway to the Red Sea and the Suez Canal, the country occupies the tip of a region that, due to its resemblance on the map to a rhinoceros' horn, is commonly referred to as the Horn of Africa. In the far north, the rugged east–west ranges of the Ogo Mountains lie at varying distances from the Gulf of Aden coast. Hot conditions prevail year-round, along with periodic monsoon winds and irregular rainfall. Geology suggests the presence of valuable mineral deposits. Somalia is separated from Seychelles by the Somali Sea and is separated from Socotra by the Guardafui Channel. Somalia contains seven terrestrial ecoregions: Ethiopian montane forests, Northern Zanzibar–Inhambane coastal forest mosaic, Somali Acacia–Commiphora bushlands and thickets, Ethiopian xeric grasslands and shrublands, Hobyo grasslands and shrublands, Somali montane xeric woodlands, and East African mangroves.

=== Constrained risk-taking === Psychologist Paul Rozin suggests that eating ordinary chilies is an example of a "constrained risk" like riding a roller coaster, in which extreme sensations like pain and fear can be enjoyed because individuals know that these sensations are not actually harmful. This method lets people experience extreme feelings without any significant risk of bodily harm.

== History == Reslizumab was initially developed by Chuan-Chu Chou at Schering-Plough and was previously known as SCH-55700. In 1993, Chou and his group at Schering-Plough were granted the patent for the design, cloning and expression of the reslizumab drug. Ception Therapeutics acquired the drug and continued its development under the name CTx55700. In 2010, Ception Therapeutics was acquired by Cephalon for $250 million and the drug continued under development under the codename CEP-38072. In 2011, Teva Pharmaceuticals acquired Cephalon for $6.8 billion and continued the development of reslizumab.

==== Eliminated in primary ==== Earnest Clayton, public health professional Peter Filler, teacher and nominee for the 2nd district in 2024 Todd Ivey, physician Marty Rocha, deputy sheriff and nominee for Texas's 28th House of Representatives district in 2024 Terry Virts, retired United States Air Force pilot and NASA astronaut (previously ran for U.S. Senate)

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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