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Background And Receptor Mechanism — Quick Reference

By Editorial Desk · published 2026-03-07 · last reviewed 2026-04-01 · News

GHRH analog raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.

Reviewed 2026-04-01. Anything still debated is marked as such rather than presented as settled.

Background and Receptor Mechanism

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.

CJC-1295 is a synthetic peptide belonging to the growth hormone-releasing hormone analog family. It comprises twenty-nine amino acid residues derived from the N-terminal region of natural GHRH. The molecule incorporates several non-natural substitutions that increase resistance to enzymatic degradation. These modifications extend its activity compared with the native hormone fragment. Researchers use it to study pituitary growth hormone secretion in laboratory and clinical settings. This compound is distinct from native GHRH in its stability profile.

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.

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 weight, DAC formAbout 3647 DaVaries with salt form
Molecular weight, non-DAC formAbout 3358 DaMOD GRF(1-29)
Solubility classWater solubleAlso dissolves in polar solvents
Reported half-life, DAC formAbout five to eight daysValues from human studies
Common synonymsCJC-1295; MOD GRF(1-29)Name depends on variant

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.

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Background and Molecular Features

The core sequence keeps the receptor-binding region of GHRH while replacing four positions that are vulnerable to dipeptidyl peptidase-4 and other proteases. Substitutions at positions 2, 8, 15, and 27 raise metabolic stability relative to the natural hormone. The N-terminal residues remain essential for activity, so changes there generally lower potency. Molecular weight sits near 3368 daltons for the tetrasubstituted analog without the linker, while the albumin-binding form is heavier because of the added maleimide group.

CJC-1295 is a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. Its sequence corresponds to the first twenty-nine residues of human GHRH, with four substitutions that slow enzymatic breakdown. Early descriptions placed the compound in research on growth hormone deficiency and related conditions, and later literature groups it with the long-acting GHRH analogs. The name appears in both laboratory and popular fitness writing, where it sometimes labels chemically different peptides.

Albumin Binding and Duration of Action

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.

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.

Handling Storage And Analytical Methods

Peptide degradation proceeds mainly through hydrolysis, oxidation of methionine, and deamidation of asparagine or glutamine residues. The maleimide group on the albumin-binding variant can also react with thiols or hydrolyze in aqueous media. Because these pathways accelerate with temperature and pH extremes, handling conditions strongly influence measured stability. Stability data in the public literature are limited and often generated under differing conditions, so general statements about shelf life should be read as approximate.

Research material is normally supplied as a freeze-dried powder in sealed vials. In that state the peptide is comparatively robust, but prolonged exposure to warmth, moisture, or light accelerates degradation. Storage at minus twenty degrees Celsius or lower, with desiccant and protection from light, is the commonly described practice. Vials should be allowed to reach room temperature before opening to limit condensation on the powder. Moisture uptake during handling is a recognized source of variability in later measurements.

Reference notes

== Selected works == Marks, Vincent; Rose, Frank Clifford (1965). Hypoglycaemia. Blackwell. Marks, Vincent; Feldman, Stanley (2006). Panic Nation: Exposing the myths we're told about food and health. Kings Road Publishing. ISBN 978-1-85782-840-5. Marks, Vincent; Richmond, Caroline (2007). Insulin Murders. Taylor & Francis. ISBN 978-1-85315-760-8. Marks, Vincent; Cantor, Thomas; Mesko, Dusan; Pullmann, Rudolf; Nosalova, Gabriela (2012). Differential Diagnosis by Laboratory Medicine: A Quick Reference for Physicians. Springer Science & Business Media. ISBN 978-3-642-55600-5. Hubbard, Ron; Marks, Vincent (2013). Clinical Applications of Monoclonal Antibodies. Springer Science & Business Media. ISBN 978-1-4613-1573-5.

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Dupilumab, sold under the brand name Dupixent, is a monoclonal antibody blocking interleukin 4 and interleukin 13 receptor signalling (IL-4R, IL-13R), used for allergic diseases such as atopic dermatitis (eczema), asthma and nasal polyps which result in chronic sinusitis. It is also used for the treatment of eosinophilic esophagitis, prurigo nodularis and chronic obstructive pulmonary disease. The most common side effects reported by the US Food and Drug Administration (FDA) include injection site reactions, upper respiratory tract infections, joint pain, and herpes viral infections. The most common side effects reported by the European Medicines Agency (EMA) include injection-site reactions (such as redness, swelling including due to fluid build-up, itching and pain), conjunctivitis (redness and discomfort in the eye) including conjunctivitis due to allergy, joint pain, cold sores, and increased blood levels of a type of white blood cell called eosinophils. It was developed by Regeneron Pharmaceuticals and Sanofi Genzyme. It received approval from the US Food and Drug Administration (FDA) for moderate-to-severe atopic dermatitis in 2017, and for asthma in 2018. The FDA considers it to be a first-in-class medication. Dupilumab is the first treatment for eosinophilic esophagitis approved by the U.S. Food and Drug Administration (FDA). Eosinophilic esophagitis is a chronic inflammatory disorder in which eosinophils, a type of white blood cell, are found in the tissue of the esophagus. Dupilumab is a monoclonal antibody that acts to inhibit part of the inflammatory pathway.

=== Bengali === Currently, the longest word in Bengali is the 33-letter-long আত্মশক্তিকরণেরসময়সীমাবদ্ধতার্থীয়তারপ্রতিবন্ধিতাক্ষরিতাবিশেষজ্ঞান, which translates to "The Boundary of Time for Self-Empowerment and Specialized Knowledge for its Corresponding Characters". Another long word often cited is the 11-letter-long অঘটনঘটনপটীয়সী, which means "one who is very skilled in doing unexpected things" or "skilled at unexpected incidents".

Sources: en.wikipedia.org

Reference notes

Glucose concentrations in the atmosphere are detected via collection of samples by aircraft and are known to vary from location to location. For example, glucose concentrations in atmospheric air ranges from 0.8 to 20.1 pg/L in inland China, to 10.3 to 142 pg/L in East coastal China.

=== Intrauterine administration === A one-year progesterone intrauterine device (IUD) for hormonal birth control was previously available in the United States and a few other countries under the brand name Progestasert. It was marketed between 1976 and 2001. The IUD was never widely used due to a relatively high contraceptive failure rate of 2.9% and the requirement of annual replacement. It contained 38 mg progesterone and released 65 μg progesterone into the uterus per day (totaling up to about 35 mg after one year). For comparison, a woman's body produces on average about 25 mg progesterone per day during the luteal phase. While effective as a form of contraception and for decreasing menstrual bleeding and discomfort, long-lived IUDs can fundamentally only deliver small amounts of progesterone per day, and hence intrauterine progesterone cannot achieve adequate circulating progesterone levels and is unsuitable as a form of systemic therapy. Aside from progesterone, IUDs of progestins, such as levonorgestrel (Mirena/Levosert/Skyla), are available as well.

There are six conditionally essential amino acids whose synthesis can be limited under special pathophysiological conditions, such as prematurity in the infant or individuals in severe catabolic distress: arginine, cysteine, glycine, glutamine, proline and tyrosine. Dietary sources of protein include grains, legumes, nuts, seeds, meats, dairy products, fish, and eggs.

is the velocity gradient perpendicular to the direction of shear. For a Newtonian fluid, the viscosity, by definition, depends only on temperature, not on the forces acting upon it. If the fluid is incompressible the equation governing the viscous stress (in Cartesian coordinates) is

The three-member tribunal was unanimous in its decision. The tribunal repeated prior criticisms of the governance of the Essendon's supplements program, which had been seen in the ASADA interim report and the Switkowski report. As a result of the verdict, the provisional suspensions on the players were lifted, and all affected players were eligible to play in Round 1. ASADA and the AFL were given a window of 21 days to appeal the decision. The verdict was handed down in private, and few other details about the reasons for the decision were released.

Sources: en.wikipedia.org

Frequently asked questions

What is CJC-1295?

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.

How do the DAC and non-DAC forms differ?

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.

What receptor does it act on?

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.

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.

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