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Background And Molecular Design — Background and Details

By Editorial Desk · published 2026-03-23 · last reviewed 2026-04-28 · Guide

Everything below concerns GRF(1-29). We keep the language plain, cite what the science says, and separate well-supported claims from open questions.

Updated 2026-04-28. Numbers and descriptions here follow the published literature rather than marketing material.

Background and Molecular Design

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.

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.

CJC-1295 is a synthetic peptide analog of growth hormone-releasing hormone, constructed on the 29-amino-acid fragment designated GRF(1-29). The name began as an internal development code during the 1990s and later spread through research supply catalogs and discussion forums. The molecule does not occur in nature; its sequence is engineered rather than isolated from tissue. Two related compounds are sold under this single label, and they differ by one appended chemical group that strongly influences how long the peptide remains in circulation.

Cjc-1295 at a glance

PropertyValueNotes
Molecular classSynthetic peptideAnalog of growth hormone-releasing hormone
Chain length29 amino acidsBased on the GRF(1-29) fragment
AppearanceWhite to off-white lyophilized powderCommon research supply form
SolubilitySoluble in water and aqueous buffersPowder requires reconstitution before use
Typical storage−20 °C or belowKept away from light and moisture

Mechanism and Pharmacokinetics

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.

Binding of the peptide to the growth hormone-releasing hormone receptor on pituitary somatotrophs triggers a G protein coupled cascade that raises cyclic AMP and opens calcium channels. The result is greater secretion of growth hormone into the bloodstream. Because the peptide acts at the same receptor as the natural hypothalamic hormone, its effect is amplified pulse size rather than an entirely separate release pathway. Receptor binding alone does not determine the response, since somatostatin tone and other inputs modulate the final output.

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.

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Persistence, Stability and Measurement

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.

Receptor Action and Clearance

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.

Once in circulation, the peptide binds the growth hormone-releasing hormone receptor displayed on pituitary somatotroph cells. Receptor activation couples to Gs proteins, elevates intracellular cyclic AMP, and drives protein kinase A signaling inside the cell. That cascade increases discharge of growth hormone into the bloodstream. The analog therefore operates through a receptor pathway that already exists for the body's own releasing hormone, rather than through an engineered artificial target.

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.

Notes from published material

== Downstream signaling == By interacting with their specific receptors, IFNs activate signal transducer and activator of transcription (STAT) complexes; STATs are a family of transcription factors that regulate the expression of certain immune system genes. Some STATs are activated by both type I and type II IFNs. However each IFN type can also activate unique STATs. STAT activation initiates the most well-defined cell signaling pathway for all IFNs, the classical Janus kinase-STAT (JAK-STAT) signaling pathway. In this pathway, JAKs associate with IFN receptors and, following receptor engagement with IFN, phosphorylate both STAT1 and STAT2. As a result, an IFN-stimulated gene factor 3 (ISGF3) complex forms—this contains STAT1, STAT2 and a third transcription factor called IRF9—and moves into the cell nucleus. Inside the nucleus, the ISGF3 complex binds to specific nucleotide sequences called IFN-stimulated response elements (ISREs) in the promoters of certain genes, known as IFN stimulated genes ISGs. Binding of ISGF3 and other transcriptional complexes activated by IFN signaling to these specific regulatory elements induces transcription of those genes. A collection of known ISGs is available on Interferome, a curated online database of ISGs (www.interferome.org); Additionally, STAT homodimers or heterodimers form from different combinations of STAT-1, -3, -4, -5, or -6 during IFN signaling; these dimers initiate gene transcription by binding to IFN-activated site (GAS) elements in gene promoters.

The product, α‑ketoadipate, is decarboxylated in the presence of NAD+ and coenzyme A to yield glutaryl-CoA, however the enzyme involved in this is yet to be fully elucidated. Some evidence suggests that the 2-oxoadipate dehydrogenase complex (OADHc), which is structurally homologous to the E1 subunit of the oxoglutarate dehydrogenase complex (OGDHc) (E.C 1.2.4.2), is responsible for the decarboxylation reaction. Finally, glutaryl-CoA is oxidatively decarboxylated to crotonyl-CoA by glutaryl-CoA dehydrogenase (E.C 1.3.8.6), which goes on to be further processed through multiple enzymatic steps to yield acetyl-CoA; an essential carbon metabolite involved in the tricarboxylic acid cycle (TCA).

=== Lungs === Fibrothorax Pulmonary fibrosis Cystic fibrosis Idiopathic pulmonary fibrosis (idiopathic meaning 'of unknown cause') Radiation-induced lung injury (following radiation therapies commonly used to treat cancer)

Pyroglutamic acid (also known as PCA, 5-oxoproline, pidolic acid) is a ubiquitous but understudied natural amino acid derivative in which the free amino group of glutamic acid or glutamine cyclizes to form a lactam. The names of pyroglutamic acid conjugate base, anion, salts, and esters are pyroglutamate, 5-oxoprolinate, or pidolate.

Sources: en.wikipedia.org

Background from the literature

Although Liu's family was anxious of their future under communist rule and considered fleeing to Hong Kong, Liu Wenhui encouraged them to stay in China and claimed the new government would treat them well. Mao Zedong appointed Liu as a Vice Chairman of the Southwest Military and Political Committee, where he served until 1954. He was also elected a member of the National Committee of the Chinese People's Political Consultative Conference and a member of the National People's Congress, and was also appointed to the Central Military Commission. In June 1950, his 24th Army was merged with the 62nd Army of the People's Liberation Army. His nephew, Liu Yuanxuan, served as its deputy commander. In 1955, Liu was awarded the Order of Liberation, First Class for his role in the Chinese Civil War.

=== The Healing Foundation === In 1998, as Treasurer of the British Association of Plastic, Reconstructive, and Aesthetic Surgeons (BAPRAS), Brough and his fellow Trustees established The Healing Foundation. Building on the groundwork laid by the Phoenix Appeal, The Healing Foundation aimed to advance research into surgical and psychological healing techniques for individuals with disfiguring conditions. Various UK medical membership bodies provided support to The Healing Foundation as Partner Member Organisations. These partnerships bolstered the charity's credibility, networking capabilities, and financial resources.These organisations were BAPRAS, the British Association of Aesthetic Surgeons, the British Psychological Society, the Craniofacial Society of Great Britain and Ireland, the British Burns Association, and the British Society for Surgery of the Hand.

Ado Jimada Gana Muhammad OON (born 18 January 1967) is a Nigerian medical doctor and public health administrator who serves as Global Programme Director of the D-8 Health and Social Protection Programme. He previously served as the Executive Director/CEO of the Nigeria's National Primary Health Care Development Agency (NPHCDA), the government agency responsible for developing national primary health care (PHC) policy and supporting states and local government areas (LGAs) to implement them. Muhammad was appointed to that position on 1 November 2011, by the administration of President Goodluck Jonathan. Prior to his appointment, Muhammad served as a special assistant to the permanent secretary, in the State House, Abuja. Muhammad succeeded Muhammad Ali Pate who was appointed as the Minister of State for Health in 2011.

=== Social Security === On March 18, 2025, the Social Security Administration announced they would be implementing tighter identity requirements starting March 31, with this date pushed forward to April 14. The new policy requires takes away the telephone option and requires individuals to either apply online or appear in-person at a field office. Applications for SSDI, Medicare, or SSI are exempted from this in-person requirement, along with applicants subject to extreme situations "such as terminal cases or prisoner pre-release scenarios". This new policy comes at a time the Trump administration is closing some field offices and laying off some Social Security staff. In late March, Wired reported that DOGE was putting together a team to migrate the Social Security base code from COBOL to a more modern programming language, with the goal of achieving this in a matter of months, whereas most experts say it should take several years to do and test this safely. It was reported in mid-April that the Trump administration had placed on the "Death Master File", renamed the "Ineligible Master File", more than 6,000 persons who are legal immigrants whom officials claim are either on a terrorism watch list or have an FBI criminal record. The White House, however, did not provide evidence for this claim. Social Security will "clawback" money from a disabled or retired person's monthly payments in cases in which overpayments are discovered.

== Organization and leadership == The National Institutes of Health (NIH) is composed of 27 Institutes and Centers, most of which include research programs led by a Scientific Director and conducted by federal researchers and their trainees at one of several NIH campus locations. Collectively, these research programs encompass the Intramural Research Program (IRP). The IRP includes the United States National Library of Medicine, an international resource for researchers, and the NIH Clinical Center, the world's largest clinical research hospital. Intramural researchers are affiliated with individual Laboratories, Branches or Centers, which are typically organized around common thematic research goals and approaches, much like a department or center at an academic institution. Within these larger structures, Principal Investigators run Sections or Units devoted to their independent research goals. Core facilities, supported by staff scientists and clinicians, are among the shared resources available to IRP researchers. Scientific interests are not bound by the organizational structure. There exists a full spectrum of scientific interest groups (called SIGs) that brings researchers from different Institutes and Centers together around common areas of scientific interest where ideas can be shared and collaborations initiated. In addition, institutes come together to work cooperatively on major initiatives focused on unraveling the complexities of disease.

Sources: en.wikipedia.org

Frequently asked questions

Does this compound occur naturally in the body?

No. It is a laboratory-synthesized analog built on a fragment of the natural hormone. The natural peptide is shorter-lived and lacks the stabilizing substitutions found in the synthetic version.

What does the abbreviation DAC refer to?

DAC stands for drug affinity complex, a chemical group that binds the peptide to serum albumin. The binding slows clearance and lengthens the time the molecule stays in plasma compared with the unmodified analog.

Why do different sources report different half-lives for the same name?

Because two distinct molecules are discussed under one informal label. The albumin-binding version clears over several days, while the form without that group clears within roughly half an hour. Mixing results from both creates inconsistent figures.

How long does the albumin-binding form remain active?

Reported values cluster in the range of several days, reflecting slow release from the albumin complex. Estimates differ across species and assay platforms. The figure describes circulation time in study settings rather than a fixed property.

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