en · de · es · fr · pt
cjc-1295-notes.peptides1004.com › Blog › Persistence, Stability And Measurement — Beginner to Advanced

Persistence, Stability And Measurement — Beginner to Advanced

By Editorial Desk · published 2025-07-27 · last reviewed 2025-09-10 · Blog

This is a working overview of GRF(1-29), written for readers who want more than a one-paragraph summary but less than a textbook.

This page was last updated on 2025-09-10 and is reviewed periodically as new material appears.

Persistence, Stability and Measurement

Lyophilized peptide powder is comparatively stable when kept dry, cold, and protected from light. Once dissolved, the molecule is vulnerable to deamidation, oxidation, and aggregation, with the rate depending on pH, buffer composition, and temperature. Alkaline conditions and repeated freeze-thaw cycles accelerate loss of the intact peptide. The methionine present in the native sequence is a known oxidation site, which is one reason it was replaced in the modified fragment. Suppliers typically recommend cold storage of solutions and use within a short window.

Analytical confirmation usually relies on reversed-phase high-performance liquid chromatography for purity and on liquid chromatography coupled to mass spectrometry for identity. Mass data reveal the expected molecular mass and can flag truncated or oxidized species. Amino acid analysis and peptide mapping provide sequence-level verification. Immunoassays are used in some biological matrices, but antibodies raised against one releasing-hormone analog may cross-react with another. Reported purity figures depend heavily on the method used, so comparisons between suppliers require matching the analytical approach.

The two variants differ dramatically in how long they persist in circulation. The form lacking the albumin-binding group has a plasma half-life measured in tens of minutes, comparable to the natural hormone fragment. The version carrying the drug affinity complex binds albumin and shows a half-life of roughly six to eight days in human studies. That figure comes from small trials that tracked hormone levels over extended periods. The physiological consequences of sustained versus pulsatile stimulation are still debated and the literature does not settle the point.

Identity and Naming History

CJC-1295 is the name used for a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound was described by a Canadian drug discovery company in the mid-2000s as a long-acting research tool. Two closely related molecules share the name in practice: one carries a drug affinity complex, or DAC, group, and one does not. The distinction matters because the two behave differently in circulation.

The peptide backbone corresponds to GRF(1-29), the first 29 residues of native growth hormone-releasing hormone, which retains most of the receptor-activating activity of the full-length molecule. Four substitutions distinguish the analog from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes slow cleavage by dipeptidyl peptidase IV, the enzyme that degrades native hormone in plasma within minutes. The outcome is improved enzymatic stability combined with a still brief residence time when no additional modification is present.

Naming in this area is inconsistent, and readers should treat product labels with care. In much of the literature and in vendor catalogs, the unqualified term refers to the albumin-binding version, while the version lacking the DAC group appears as modified GRF(1-29), mod GRF(1-29), or the same name with a without-DAC qualifier. Because one abbreviation has been applied to both materials, the only reliable way to identify a sample is to check the stated sequence and the presence of the linker.

Cjc-1295 at a glance

PropertyValueNotes
Molecular massApproximately 3.4 to 3.6 kDaDepends on whether the affinity complex is attached
AppearanceWhite to off-white lyophilized powderFreeze-dried solid, often in a sealed vial
SolubilitySoluble in water and aqueous buffersDissolution rate varies with pH and buffer salt
Typical storageBelow minus 20 degrees Celsius, dry and darkDissolved material is usually kept cold and used promptly
Common analytical methodsReversed-phase HPLC and mass spectrometryPeptide mapping and amino acid analysis add sequence detail

Compound Identity and Development History

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.

Two forms circulate in research settings and are frequently confused. One carries the drug affinity complex and is often written as CJC-1295 with DAC; the other lacks that group and is usually called modified GRF(1-29). The two share the same core sequence but differ sharply in how long they persist in blood. Products labelled only as CJC-1295 normally refer to the version carrying the complex. Documentation that omits the distinction leaves the intended molecule ambiguous.

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.

Related pages on this site

Analytical Measurement And Stability

Identity and purity are established with reversed phase high performance liquid chromatography coupled to mass spectrometry. The chromatographic step separates the target peptide from truncated sequences and deletion products, while the mass measurement confirms the expected molecular weight to within a fraction of a dalton. Because the two common variants differ by the presence of the linker, mass alone can distinguish them in the unconjugated state. Amino acid analysis and peptide mapping are used when sequence level confirmation is required.

Lyophilized material is generally stable for extended periods when held at minus twenty degrees Celsius or below and protected from moisture and light. In solution the peptide is more labile; bond hydrolysis, aggregation and oxidation of susceptible residues all proceed faster at ambient temperature. Repeated freeze and thaw cycles should be avoided because they promote clumping and loss of soluble material. The conjugated variant adds a further consideration, since the maleimide group can hydrolyze in aqueous buffer and lose its ability to react with albumin.

Laboratory handling centers on minimizing exposure to water, heat and oxygen before use. Working solutions are typically prepared in sterile water or a mild buffer, and any residual particulate matter is removed by filtration. When the powder dissolves slowly, a small proportion of acetonitrile or dilute acetic acid is sometimes added as a co-solvent. Containers are kept sealed and desiccated between uses. Records of lot number, reconstitution date and storage conditions support later comparison of results across experiments.

CJC-1295 Background and Mechanism

CJC-1295 is a synthetic peptide designed to mimic growth hormone-releasing hormone (GHRH), the endogenous signal that prompts the pituitary gland to release growth hormone. The compound is a modified fragment of the natural hormone, spanning the first twenty-nine amino acids of GHRH with several substitutions that slow enzymatic breakdown. Two variants circulate in research settings: one carrying a drug affinity complex (DAC) and one without it. The DAC-free form is frequently labelled Mod GRF(1-29) in catalogs and discussion forums.

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.

Further detail

== Introduction == Banting lived at the house in London for ten months, beginning in June, 1920. He attempted a private medical practice and when it was unsuccessful, he began working at the University of Western Ontario; his research for a lecture there was what inspired his 25 word idea that provided the key to discovering insulin, and prevented the certain death of those affected by diabetes. Banting returned to the University of Toronto to begin his research on insulin in the spring of 1921. Banting House is dedicated to the story behind the discovery of insulin, as well as Banting's life and career. Its galleries focus on everything from his time spent in London, to his contributions in both World Wars, to his efforts as an artist. Some notable artifacts include Banting's original art, desk, medicine cabinet, and bed frame, as well as his Military Cross, the KBE, and his official replica of the Nobel Prize. Banting House was designated a National Historic Site of Canada in 1997.

=== Disorders of amino-acid transport and metabolism === 270 Disorders of amino-acid transport and metabolism 270.0 Disturbances of amino-acid transport Cystinosis Cystinuria Hartnup disease 270.1 Phenylketonuria (PKU) 270.1 Tetrahydrobiopterin deficiency 270.2 Other disturbances of aromatic amino-acid metabolism Albinism Alkaptonuria Hypertyrosinemia Ochronosis Waardenburg syndrome 270.3 Disturbances of branched-chain amino-acid metabolism Isobutyryl-coenzyme A dehydrogenase deficiency Isovaleric acidemia Maple syrup urine disease Methylmalonic acidemia Propionic acidemia 270.4 Disturbances of sulphur-bearing amino-acid metabolism Homocystinuria 270.5 Disorders of histidine metabolism Carnosinemia Histidinemia Hyperhistidinemia Imidazole aminoaciduria Urocanic aciduria 270.6 Disorders of urea cycle metabolism Citrullinemia Hyperammonemia 270.7 Disorders of straight-chain amino-acid metabolism Hyperlysinemia Pipecolic acidemia Saccharopinuria 270.8 Other specified disorders of amino-acid metabolism Trimethylaminuria

The Drug Prevention Network of Canada states that harm reduction has "...come to represent a philosophy in which illicit substance use is seen as largely unpreventable, and increasingly, as a feasible and acceptable lifestyle as long as use is not 'problematic'", an approach which can increase "acceptance of drug use into the mainstream of society". They say harm reduction "...sends the wrong message to ... children and youth" about drug use. In 2008, the Declaration of World Forum Against Drugs criticized harm reduction policies that "...accept drug use and do not help drug users to become free from drug abuse", which the group say undermines "...efforts to limit the supply of and demand for drugs." They state that harm reduction should not lead to less efforts to reduce drug demand. Pope Benedict XVI criticised harm reduction policies with regards to HIV/AIDS, saying that it was "a tragedy that cannot be overcome by money alone, that cannot be overcome through the distribution of condoms, which even aggravates the problems". This position was in turn widely criticised for misrepresenting and oversimplifying the role of condoms in preventing infections. A March 2025 study exploring the association of safer supply and decriminalization policy with opioid overdose outcomes in British Columbia, Canada, found that neither policy "appeared to mitigate the opioid crisis, and both were associated with an increase in opioid overdose hospitalizations."

Sources: en.wikipedia.org

Supporting material

The period from 1958 to 1968 saw tremendous growth in aviation. Improvements in aviation safety and accident investigation procedures were rapidly advancing. In 1963, the Civil Aeronautics Board, under the leadership of then Deputy Director Bobbie R. Allen, established the National Aircraft Accident Investigation School in Oklahoma City. The ICAO's third accident investigation division meeting, held in Montreal, Canada, in January 1965, laid the foundation for accident investigations throughout the world. The proposals were presented by the Director of the Civil Aeronautics Board Bureau of Safety, Bobbie R. Allen, who headed the U.S. delegation. The U.S. formally adopted the proposals at the White House on December 1, 1965. The top 10 countries with the highest number of fatal civil airliner accidents from 1945 to 2021 are the United States, Russia, Canada, Brazil, Colombia, United Kingdom, France, Indonesia, Mexico, and India. The United Kingdom is noted to have the highest number of air crashes in Europe, with a total of 110 air crashes within the time period, and Indonesia is the highest in Asia at 104, followed by India at 95.

Human ASH1L protein is 2969 amino acids long with a molecular weight of 333 kDa. ASH1L has an associated with SET domain (AWS), a SET domain, a post-set domain, a bromodomain, a bromo-adjacent homology domain, and a plant homeodomain finger (PHD finger). Human and Drosophila Ash1 share 66% and 77% similarity in their SET and PHD finger domains, respectively. A bromodomain is not present in Drosophila Ash1. The SET domain is responsible for ASH1L's histone methyltransferase (HMTase) activity. Unlike other proteins that contain a SET domain at their C terminus, ASH1L has a SET domain in the middle of the protein. The crystal structure of the human ASH1L catalytic domain, including the AWS, SET, and post-SET domains, has been solved to 2.9 angstrom resolution. The structure shows that the substrate binding pocket is blocked by a loop from the post-SET domain, and because mutation of the loop stimulates ASH1L HMTase activity, it was proposed that this loop serves a regulatory role.

Pyocyanin (PCN−) is one of the many toxic compounds produced and secreted by the Gram negative bacterium Pseudomonas aeruginosa. Pyocyanin is a blue secondary metabolite, turning red below pH 4.9, with the ability to oxidise and reduce other molecules and therefore kill microbes competing against P. aeruginosa as well as mammalian cells of the lungs which P. aeruginosa has infected during cystic fibrosis. Since pyocyanin is a zwitterion at blood pH, it is easily able to cross the cell membrane. There are three different states in which pyocyanin can exist: oxidized (blue), monovalently reduced (colourless) or divalently reduced (red). Mitochondria play an important role in the cycling of pyocyanin between its redox states. Due to its redox-active properties, pyocyanin generates reactive oxygen species.

Silicon (14Si) has 25 known isotopes, with mass number ranging from 22 to 46. 28Si (the most abundant isotope, at 92.24%), 29Si (4.67%), and 30Si (3.07%) are stable. The longest-lived radioisotope is 32Si, which occurs naturally in tiny quantities from cosmic ray spallation of argon. Its half-life has been determined to be approximately 157 years; it beta decays with energy 0.21 MeV to 32P, which in turn beta-decays, with half-life 14.269 days to 32S; neither step has gamma emission. After 32Si, 31Si has the second longest half-life at 157.2 minutes. All others have half-lives under 7 seconds.

Sources: en.wikipedia.org

Notes from published material

Hughes Helicopters was renamed McDonnell Douglas Helicopter Systems later in August 1984. Although the direct link with Hughes was broken, the helicopter designs created by Hughes Helicopters would continue to be produced by Boeing Rotorcraft Systems, MD Helicopters, and Schweizer RSG.

=== Electronation and de-electronation === The electrochemist John Bockris proposed the words electronation and de-electronation to describe reduction and oxidation processes, respectively, when they occur at electrodes. These words are analogous to protonation and deprotonation. IUPAC has recognized the terms electronation and de-electronation.

Maúrtua further added that Castillo met Maduro during the VI Summit of CELAC, where many Latin American leaders were present. The Foreign Minister stated that in such multilateral events, spontaneous meetings are natural. Subsequently, the Free Peru caucus accused Maúrtua of trying to impose his political agenda on the President, and called for Maúrtua's resignation: "The foreign minister remained silent... in the face of the audacity of his Vice Foreign Minister Luis Enrique Chávez to contradict the president in his decision to maintain friendly relations and cooperation with Venezuela and the Maduro government. Therefore, having transgressed the provisions of Article 118, paragraph 11 of the Political Constitution, our caucus demands the resignation of both the minister and the vice minister." On 15 October 2021, following the appointment of the Vásquez cabinet, Richard Rojas Garcia was appointed as Peru's ambassador to Venezuela. This in effect established official diplomatic relations with Venezuela. Some media outlets have claimed that Rojas is the right-hand man of Vladimir Cerrón. However, soon afterward a judge ruled that Rojas could not leave the country for 6 months, due to his alleged link with members of "Los Dinámicos del Centro." Afterward, Foreign Minister Óscar Maúrtua claimed that Rojas' appointment as ambassador to Venezuela never took place, "since the corresponding process was not concluded. In this sense, Peru is proceeding to inform the Government of Venezuela that the proposed appointment of Mr.

Sources: en.wikipedia.org

Frequently asked questions

What is the difference between the forms with and without a drug affinity complex?

The version carrying the affinity complex bears a maleimide group that binds serum albumin, which extends its circulation time to several days. The version without it lacks this group and clears within roughly half an hour. The two are chemically related but behave very differently once in the body.

Is CJC-1295 the same as MOD GRF 1-29?

In common usage the name without the affinity complex is often equated with MOD GRF 1-29, a fragment carrying four stabilizing substitutions. Strictly speaking, the term originally referred to the albumin-binding version. The overlap in naming causes frequent ambiguity in both informal and technical writing.

How is the compound identified in a laboratory?

Reversed-phase chromatography separates the peptide from related impurities and yields a purity estimate. Mass spectrometry confirms the molecular mass and detects modifications such as oxidation. Sequence-level checks rely on peptide mapping or amino acid analysis when stronger confirmation is needed.

Is this compound a naturally occurring hormone?

No. It is a laboratory-made analog of growth hormone-releasing hormone. The natural hormone is a 44-residue peptide, while the analog is built on a shorter 29-residue fragment.

Network