If you have been reading about cjc-1295 and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2025-12-14. Numbers and descriptions here follow the published literature rather than marketing material.
Two principal forms appear in the literature and in research supply. One carries a drug affinity complex, a maleimide-based group that forms a covalent bond with circulating albumin. This linkage slows clearance and produces a long-lasting elevation of peptide levels. The other form lacks that group and is often labeled MOD GRF(1-29). It has a much shorter circulation time. Both variants retain the same core receptor-binding sequence. Reported half-lives differ substantially between the two.
At the pituitary, the peptide binds the growth hormone-releasing hormone receptor on somatotroph cells. Receptor activation raises intracellular cyclic AMP and triggers release of stored growth hormone. Somatostatin and other hypothalamic signals modulate this response. Negative feedback from insulin-like growth factor 1 also influences output. The same regulatory architecture operates with the native hormone. Whether the synthetic analog alters feedback dynamics over repeated exposure remains an open question. Most published receptor work uses cell models rather than intact human systems.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular weight, DAC form | About 3647 Da | Varies with salt form |
| Molecular weight, non-DAC form | About 3358 Da | MOD GRF(1-29) |
| Solubility class | Water soluble | Also dissolves in polar solvents |
| Reported half-life, DAC form | About five to eight days | Values from human studies |
| Common synonyms | CJC-1295; MOD GRF(1-29) | Name depends on variant |
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.
Clearance profiles diverge sharply between the two versions. The albumin-binding molecule stays in plasma for several days, whereas the unmodified analog is largely gone within about half an hour in reported work. Cleavage by dipeptidyl peptidase IV is a major contributor to the short life of the unmodified sequence. These gaps mean the two versions cannot be substituted for each other in study design or in reading results side by side.
Reports on this compound commonly follow serum growth hormone and insulin-like growth factor 1 across defined time windows. Protocols differ in sampling frequency, assay platform, and participant characteristics, which makes direct comparison between publications difficult. Some work focuses on pulsatile release patterns instead of average concentrations. Whether repeated exposure alters endogenous hormone rhythms over long periods remains an open question, and the formal literature is thinner than the volume of informal commentary implies.
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.
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Water extraction: Coffee beans are soaked in water. The water, which contains many other compounds in addition to caffeine and contributes to the flavor of coffee, is then passed through activated charcoal, which removes the caffeine. The water can then be put back with the beans and evaporated dry, leaving decaffeinated coffee with its original flavor. Supercritical carbon dioxide extraction: Supercritical carbon dioxide is an excellent nonpolar solvent for caffeine, and is safer than the organic solvents that are otherwise used. The extraction process is simple: CO2 is forced through the green coffee beans at temperatures above 31.1 °C and pressures above 73 atm. Under these conditions, CO2 is in a "supercritical" state: It has gaslike properties that allow it to penetrate deep into the beans but also liquid-like properties that dissolve 97–99% of the caffeine. The caffeine-laden CO2 is then sprayed with high-pressure water to remove the caffeine. The caffeine can then be isolated by charcoal adsorption (as above) or by distillation, recrystallization, or reverse osmosis. Extraction by organic solvents: Certain organic solvents such as ethyl acetate present much less health and environmental hazard than chlorinated and aromatic organic solvents used formerly. Another method is to use triglyceride oils obtained from spent coffee grounds. Decaffeination does not happen completely; some caffeine remains in the coffee beans. Some commercially available decaffeinated coffee products contain considerable levels.
=== Structure of the eye === Cornea, at the surface of the eye, is considered to be made of plywood-like structure of collagen, due to the self-organization properties of sufficiently dense collagen. Yet, the collagenous orientation in lamellae is still under debate in this tissue. Keratoconus cornea can also be imaged by SHG to reveal morphological alterations of the collagen. Third-Harmonic Generation (THG) microscopy is moreover used to image the cornea, which is complementary to SHG signal as THG and SHG maxima in this tissue are often at different places.
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=== Cellulose casings === Cellulose, usually from cotton linters or wood pulp, is processed to make viscose, which is then extruded into clear, tough casings for making wieners and franks. They also are shirred for easier use and can be treated with dye to make "red hots". The casing is peeled off after cooking, resulting in "skinless" franks. Cellulosic viscose solutions are combined with wood or for example abacá pulp to make large diameter fibrous casings for bologna, cotto salami, smoked ham and other products sliced for sandwiches. This type is also permeable to smoke and water vapor. They can be flat or shirred, depending on application, and can be pretreated with smoke, caramel color, or other surface treatments.
Collagen is the main component of the extracellular matrix (ECM). The collagen superfamily consists of 28 different types of collagen. Although the function and hierarchical structure of these collagens may vary, they all share the defining structural feature known as the triple helix, where three left handed polyproline II-type (PPII) helices assemble to form a right-handed supercoiled helical motif. Short synthetic peptides known as collagen mimetic peptides (CMPs) or collagen-like peptides (CLPs) have played a major role in elucidating the 3D structure of the collagen triple helix, its folding kinetics, and thermal stability as small triple helical models. CMPs, CLPs, and CHPs are all very similar in terms of their amino acid sequences but only when CMPs or CLPs are heated above their melting temperatures, do they exist in the dissociated, single-stranded state and can be considered as CHPs.
=== Membranes === Membranes can be either of connective tissue or epithelial tissue. Connective tissue membranes include the meninges (the three membranes covering the brain and spinal cord) and synovial membranes that line joint cavities. Mucous membranes and serous membranes are epithelial with an underlying layer of loose connective tissue.
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The aldehyde groups of the triose sugars are oxidised, and inorganic phosphate is added to them, forming 1,3-bisphosphoglycerate. The hydrogen is used to reduce two molecules of NAD+, a hydrogen carrier, to give NADH + H+ for each triose. Hydrogen atom and ion balance and charge balance are both maintained because the phosphate (Pi) group actually exists in the form of a hydrogen phosphate anion (HPO2−4), which dissociates to contribute the extra H+ ion and gives a net charge of −3 on both sides. Here, arsenate ([AsO4]3−), an anion akin to inorganic phosphate may replace phosphate as a substrate to form 1-arseno-3-phosphoglycerate. This, however, is unstable and readily hydrolyzes to form 3-phosphoglycerate, the intermediate in the next step of the pathway. As a consequence of bypassing this step, the molecule of ATP generated from 1–3 bisphosphoglycerate in the next reaction will not be made, even though the reaction proceeds. As a result, arsenate is an uncoupler of glycolysis.
The East Prussian plebiscite (German: Volksabstimmung in Ostpreußen), also known as the Allenstein and Marienwerder plebiscite or Warmia, Masuria and Powiśle plebiscite (Polish: Plebiscyt na Warmii, Mazurach i Powiślu), was a plebiscite for the self-determination of the regions of southern Warmia (Ermland), Masuria (Mazury, Masuren) and Powiśle, which had been in parts of the East Prussian Government Region of Allenstein and of the West Prussian Government Region of Marienwerder in accordance with Articles 94 to 97 of the Treaty of Versailles. Prepared in early 1920, the plebiscite took place on 11 July 1920 and was conducted by German authorities under Inter-Allied control. The plebiscite reported that most voters had selected East Prussia over Poland (over 97% in the Allenstein Plebiscite Area and 92% in the Marienwerder Plebiscite Area). As a result, most of the territories in question remained in the Free State of Prussia and therefore in Germany.
ribosome A macromolecular complex made of both RNA and protein which serves as the site of protein synthesis by translation. Ribosomes have two subunits, each of which consists of one or more strands of ribosomal RNA bound to various ribosomal proteins: the small subunit, which reads the messages encoded in messenger RNA molecules, and the large subunit, which links amino acids in sequence to form a polypeptide chain. Ribosomes are essential and ubiquitous in all cell types and are used by all known forms of life.
Semiconducting CNTs are more strongly attracted by gel than metallic CNTs. While it shows potential, this application is limited to the separation of semiconducting (n,m) species. ATPE uses two water-soluble polymers such as polyethylene glycol (PEG) and dextran. When mixed, two immiscible aqueous phases form spontaneously, and each of the two phases shows a different affinity to CNTs. Partition depends on the solvation energy difference between two similar phases of microscale volumes. By changing the separation system or temperatures, and adding strong oxidants, reductants, or salts, the partition of CNTs species into the two phases can be adjusted. Despite the progress that has been made to separate and purify CNTs, many challenges remain, such as the growth of chirality-controlled CNTs, so that no further purification is needed, or large-scale purification.
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It is a synthetic peptide modeled on growth hormone-releasing hormone. The molecule is used in research on pituitary growth hormone secretion. It differs from the natural hormone through several stabilizing substitutions.
The DAC form carries a maleimide group that binds albumin and extends circulation time. The non-DAC form lacks this group and clears much faster. Both share the same receptor-binding core.
It targets the growth hormone-releasing hormone receptor on pituitary somatotroph cells. Activation raises cyclic AMP and promotes growth hormone release. Normal feedback pathways remain part of the response.
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.