en · de · es · fr · pt
cjc-1295-notes.peptides5388.com › Topic › Structure And Receptor Pharmacology — Evidence Review

Structure And Receptor Pharmacology — Evidence Review

By Editorial Desk · published 2025-09-08 · last reviewed 2025-10-27 · Topic

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

Updated 2025-10-27. Numbers and descriptions here follow the published literature rather than marketing material.

Structure And Receptor Pharmacology

CJC-1295 belongs to a class of synthetic peptides modeled on growth hormone releasing hormone, a forty-four amino acid signal produced by the hypothalamus. The compound is built from the first twenty-nine residues of the natural sequence, with four substitutions introduced at positions 2, 8, 15 and 27. These changes were designed to slow enzymatic breakdown while preserving receptor activation. The result is a peptide that is shorter than native GHRH and considerably more resistant to ordinary clearance pathways in circulation.

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.

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.

Cjc-1295 at a glance

PropertyValueNotes
Peptide classSynthetic GHRH analogueBuilt on a 29 residue sequence
Primary targetGHRH receptor (GHRHR)Class B G protein coupled receptor
Unconjugated half lifeMinutesLimited by protease degradation
Key modificationFour residue substitutionsPositions 2, 8, 15 and 27
Common synonymModified GRF(1-29)Usually denotes the form without DAC

Handling, Stability and Analysis

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.

Related pages on this site

Background and Naming Conventions

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.

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.

Background from the literature

== Legal status == The US Drug Enforcement Administration issued a notice of intent to publish a temporary order to schedule isotonitazene in Schedule I of the Controlled Substances Act, which came into effect on 20 August 2020.

==== Hospitalized patients ==== Remdesivir was approved for medical use in the United States in October 2020. The US Food and Drug Administration (FDA) approved remdesivir based on the agency's analysis of data from three randomized, controlled clinical trials that included participants hospitalized with mild-to-severe COVID‑19. The FDA granted approval and reissued the revised EUA to Gilead Sciences Inc. The FDA approved remdesivir based primarily on evidence from three clinical trials (NCT04280705, NCT04292899, and NCT04292730) of 2043 hospitalized participants with COVID‑19. The trials were conducted at 226 sites in 17 countries including the United States. In November 2020, the World Health Organization (WHO) updated its guideline on therapeutics for COVID‑19 to include a conditional recommendation against the use of remdesivir, triggered by results from the WHO Solidarity trial. Meanwhile, the Public Health Agency of Canada's COVID‑19 Clinical Pharmacology Task Group recommended that remdesivir only be administered to hospitalized patients as part of a randomized controlled trial due to limited information on risks and benefits. In January 2022, the Canadian component of the WHO Solidarity Trial reported that in-hospital people with COVID‑19 treated with remdesivir had 17% lower relative risk of death (18.7% versus 22.6% death rates) and 47% reduced relative risk for needing oxygen and mechanical ventilation (8.0% versus 15.0%) compared to people receiving standard-of-care treatments.

Bancroft, EA (October 2007). "Antimicrobial resistance: it's not just for hospitals". JAMA. 298 (15): 1803–1804. doi:10.1001/jama.298.15.1803. PMC 2536104. PMID 17940239. Larson, E (2007). "Community factors in the development of antibiotic resistance". Annual Review of Public Health. 28 (1): 435–447. doi:10.1146/annurev.publhealth.28.021406.144020. PMID 17094768.

Sources: en.wikipedia.org

Further detail

== Amphiphiles == Amphiphiles are molecules that have both hydrophobic and hydrophilic domains. Detergents are composed of amphiphiles that allow hydrophobic molecules to be solubilized in water by forming micelles and bilayers (as in soap bubbles). They are also important to cell membranes composed of amphiphilic phospholipids that prevent the internal aqueous environment of a cell from mixing with external water.

24998Cf + 157N → 260105 + 4 n These results did not confirm the JINR findings regarding the 9.4 MeV or 9.7 MeV alpha decay of 260105, leaving only 261105 as a possibly produced isotope. JINR then attempted another experiment to create element 105, published in a report in May 1970. They claimed that they had synthesized more nuclei of element 105 and that the experiment confirmed their previous work. According to the paper, the isotope produced by JINR was probably 261105, or possibly 260105. This report included an initial chemical examination: the thermal gradient version of the gas-chromatography method was applied to demonstrate that the chloride of what had formed from the SF activity nearly matched that of niobium pentachloride, rather than hafnium tetrachloride. The team identified a 2.2-second SF activity in a volatile chloride portraying eka-tantalum properties, and inferred that the source of the SF activity must have been element 105. In June 1970, JINR made improvements on their first experiment, using a purer target and reducing the intensity of transfer reactions by installing a collimator before the catcher. This time, they were able to find 9.1 MeV alpha activities with daughter isotopes identifiable as either 256103 or 257103, implying that the original isotope was either 260105 or 261105.

General Dan Caine, Chairman of the Joint Chiefs of Staff, said in a 3 January press conference that the US military had spent months planning and rehearsing the operation, with forces positioned and ready by early December. In late December, the US escalated its military efforts against Venezuela onto land, including striking a remote northern port reportedly used by Tren de Aragua for smuggling. At that time, Maduro rejected an offer from the US to go into exile in Turkey. According to The New York Times, Maduro's public displays downplaying the seriousness of the American threats in the weeks before the operation, such as through public dancing on a stage to electronic music sampling one of his speeches in which Maduro said "No crazy war", were a factor in Trump deciding to begin the operation. President Trump stated that the operation had been ready to launch several days earlier but was postponed due to poor weather and cloud cover, which made flying into Caracas hazardous. General Caine, added that US forces waited for conditions to improve to minimize the risk to civilian populations and explained that the mission proceeded only after the weather "broke just enough" to allow aircraft to maneuver safely into position.

Sources: en.wikipedia.org

Frequently asked questions

Is CJC-1295 the same as modified GRF(1-29)?

The names are often used interchangeably in casual writing, but they are not strictly identical. Modified GRF(1-29) refers to the unconjugated analogue carrying only the four substitutions. The version sold as CJC-1295 with DAC includes the albumin binding linker and clears much more slowly.

What does the acronym DAC refer to?

DAC stands for drug affinity complex, a term describing the maleimidopropionic acid linker. This group forms a covalent bond with the cysteine residue on serum albumin after administration. The resulting adduct is what extends the circulating half life from minutes to days.

Does this peptide occur naturally in the body?

No. It is entirely synthetic and does not correspond to any known endogenous peptide. The design starts from human growth hormone releasing hormone and introduces deliberate substitutions. Any biological effect comes from mimicking the natural hormone at its receptor.

What distinguishes CJC-1295 from natural GHRH?

The synthetic peptide keeps the receptor-binding region of GHRH but carries substitutions that resist enzymatic cleavage. In the DAC version, an added group also anchors the molecule to albumin, extending its presence in the bloodstream.

Network