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Structure And Receptor Pharmacology — Reference Sheet

By Editorial Desk · published 2026-06-29 · last reviewed 2026-08-01 · Info

GHRH receptor is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.

Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.

Structure And Receptor Pharmacology

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.

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.

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

CJC-1295 Structure And Mechanism

The drug affinity complex is a maleimidopropionic acid group attached to a lysine side chain. It reacts with the free thiol of cysteine-34 on circulating albumin, forming a covalent bond. This conjugation keeps the peptide in the bloodstream and shields it from rapid renal filtration and proteolysis. Reported circulation half-lives for the albumin-bound form fall in the range of roughly six to nine days in early human studies.

Binding to GHRH receptors on pituitary somatotroph cells triggers cyclic AMP signaling and stimulates growth hormone synthesis and release. Because the peptide acts upstream of the pituitary, effects are mediated through endogenous growth hormone rather than direct receptor activation in peripheral tissues. Increases in insulin-like growth factor 1 are generally described as a downstream consequence. Most published human exposure data come from small early-stage studies, and the clinical significance of the pharmacokinetic profile remains incompletely characterized.

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Molecular Background and Naming

The peptide backbone includes a D-alanine at position two, which resists cleavage by dipeptidyl peptidase IV, and several other substitutions that reduce degradation. Its molecular weight is roughly 3.4 kDa without the linker and about 3.6 kDa with it. The molecule is water soluble and is normally supplied as a lyophilized powder. Precise sequence and mass values depend on which variant is described, so technical documents usually state the exact form being referenced.

CJC-1295 is a synthetic peptide designed as a long-acting analogue of growth hormone-releasing hormone (GHRH). Its structure derives from the first 29 amino acids of native GHRH, a fragment often called GRF(1-29). Four substitutions were introduced to slow enzymatic breakdown and extend activity relative to the natural sequence. The compound was developed by ConjuChem as part of a broader effort to improve the pharmacokinetic profile of peptide hormones. It is studied in laboratory and clinical research settings rather than appearing as a naturally occurring substance.

Mechanism and Pharmacokinetics

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.

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.

Reference notes

In each department, in each province of Peru occupied by the Colombians, small dictators exercised their functions, widely empowered to fleece the people (...) Prototype of those little dictators who in 1824 sowed terror in Peru, is that Manterola appointed governor of Huamachuco by Bolívar, who carried out his functions accompanied by his mistress, and at the same time that he looted the unfortunate towns of his jurisdiction and tortured his neighbors." Bolívar was also accused of carrying out a geopolitics with a clear anti-Peruvian direction in Gran Colombia, with absolute opposition to the interests of said political society, both in its form of the Viceroyalty of Peru and of the Republic of Peru, denouncing a mixture of admiration and envy of Peru's economic privileges, as well as suspicion for its population, which he constantly described as contemptuous, even before intervening in its political affairs, since this antipathy would have been clearly distilled since the years of the famous Jamaica Letter. (…) The Viceroyalty of Peru, whose population amounts to a million and a half inhabitants, is undoubtedly the most submissive and from which the most sacrifices have been made for the king's cause, (…) Chile can be free. Peru, on the contrary, contains two enemy elements of every fair and liberal nature: gold and slaves [referring to the Indians]. The first corrupts everything; the second is corrupted by itself. The soul of a servant [referring to the common people of Peru] rarely manages to appreciate healthy freedom; he rages in riots or humbles himself in chains.

High-throughput experimentation involves increasing throughput by scaling up the number of experiments that can be run in parallel using a common sample form factor and technique. When space or materials are limited, minor factors must be assigned to progressively smaller fractions to increase the number of replicates. Cloud labs, on the other hand, do not fundamentally scale up a single experiment but rather increase the number of types of experiments that can be run in parallel. For example, with a cloud lab, a scientist could simultaneously attempt dozens of different purification methods that each uses completely unique equipment sets. HTE work cells can sometimes be accessed remotely to trigger a run on a library or digitally monitor a run. However, this remote monitoring or screen triggering does not impact the development that must take place in advance of a run. Often with HTE, scientists must group samples into libraries that use the same or very similar form factor containers such that the work cell can more easily traffic and address each sample in an integrated manner. Therefore, scientists need to standardize sample form factors of samples and handle the sample prep offline of the work cell. Cloud labs can work with samples in hundreds or even thousands of unique containers, providing additional flexibility relative to traditional labs (even those that are using HTE), and allowing processing of a larger number of samples.

=== Peptide synthesis/ACTH === The first chemical synthesis of an active peptide hormone, the nine amino acid cyclic peptide, oxytocin, was achieved in 1954 by du Vigneaud for which he was awarded the Nobel Prize. At the same time, the isolation and structure determination of the anterior pituitary hormone, ACTH, was being pursued in three laboratories. The peptide was eventually determined to be 39 amino acids in length, however enzymatic and mild acid cleavage suggested that a structure comprising only the first 24 amino acids had full biological activity. It was apparent from the outset that ACTH contained the amino acid Arginine and thus methods had to be developed for the incorporation of this basic amino acid into peptides. Hofmann and his group set about this task. Their efforts led to the synthesis of the melanocyte stimulating hormone, β-MSH, which corresponds to the first 13 amino acids of ACTH and to the synthesis of a fully active ACTH peptide corresponding to the amino acid sequence of the first 23 amino acids. In the course of the peptide synthetic work on ACTH, a novel chain cleavage was observed at an acyl-proline linkage while removing protecting groups using metallic sodium in liquid ammonia. This unexpected reaction has subsequently proved useful in special analytical cases.

=== Monoamine oxidase inhibitors === Monoamine oxidase inhibitors (MAOIs) are first-generation antidepressants effective for anxiety treatment but their dietary restrictions, adverse effect profile and availability of newer medications have limited their use. MAOIs include phenelzine, isocarboxazid and tranylcypromine. Pirlindole is a reversible MAOI that lacks dietary restriction.

== History == The efficacy of bulevirtide was demonstrated in a multi-center, randomized, open-label, parallel-arm phase III trial. In Trial MYR301, participants were randomly assigned to immediate treatment with bulevirtide 8.5 mg once daily for 144 weeks or to delayed treatment with an observational period of 48 weeks followed by bulevirtide 8.5 mg once daily for 96 weeks.

Sources: en.wikipedia.org

Notes from published material

Notably, fecal ssRNA was identified as a natural Piezo1 ligand, and ssRNA-stimulated 5-HT synthesis from the gut was evoked in a MyD88/TRIF-independent manner. Colonic infusion of RNase A suppressed gut motility and increased bone mass. These findings suggest gut ssRNA as a master determinant of systemic 5-HT levels, indicating the ssRNA-Piezo1 axis as a potential prophylactic target for treatment of bone and gut disorders. Studies in 2008, 2010 and 2019 have opened the potential for serotonin research to treat bone mass disorders.

=== Endoscopy === After Edlich learned about endoscopes in Asia, he received an endoscope for gastroscopic visualization of the patient's stomach. As a surgical resident, Edlich was the first physician to do a gastroscopy at the University of Minnesota Medical Center. Edlich's picture was featured on the cover of Postgraduate Medicine, the Journal of Applied Medicine, in November 1968. His experiences with gastroscopy led to the first minimally invasive surgical procedure at the University of Minnesota Hospital, an endoscopic gastrostomy. Edlich soon realized the limitations of the thick, narrow-diameter latex Ewald tubes that were being used to evacuate blood clots from the patient's stomach before endoscopic examination. Edlich devised a thin-walled, transparent, plastic tube for evacuation of blood clots from a patient's stomach.

== Slurry ice generators == Slurry ice is generated using a unique type of ice-making technology. Conventional ice generators produce sharp edged, dry ice fragments, not the small, spherical crystals found in slurry ice. In traditional brine chiller systems, crystals forming inside the solution would block or damage the system.

=== Measuring methods for contents of cannabinoids === Measuring methods for cannabinoids are based on the extraction of fluids from the hemp plant. Research and studies conducted at the University of Wuppertal (Germany) have shown that extracts contain much less of the initial contents of the hemp plant present in the juice. Besides, with extracts there is a risk of residues of solvents. There are no specific measuring methods for the quantities of cannabinoids in hemp juice accepted by all states. The EU is working on the development of a commonly accepted procedure. An alternative procedure used for the extraction of fluids first filters and centrifuges the hemp juice. The findings however showed no traces of cannabinoids because the characteristic contents of the hemp plant solely can be found in the unfiltered hemp juice.

Sources: en.wikipedia.org

Further detail

=== Daniel Van Deventer === Daniel Van Deventer (Alex Akpobome), nicknamed “DVD,” is a Pierpoint trader transferred from New York to London during plans to consolidate the two offices. A former protégé of Eric Tao, DVD’s rapid rise places him in direct competition with Eric, ultimately contributing to Eric’s demotion after the loss of Felim Bichan as a client. DVD assumes Eric’s responsibilities as CPS MD and begins a sexual relationship with Harper, encouraging her to consider relocating to New York as the London office faces closure. He later suspends Harper after secretly listening in on a call in which she helps Jesse Bloom unload positions at Pierpoint’s expense. DVD grows disillusioned with Pierpoint after being instructed by Adler to ignore Nicole Craig’s sexual assault of Venetia Berens, and sympathizes with Harper upon learning she was also assaulted by Nicole. He agrees to leave the firm with Harper, Eric, and Rishi, but is ultimately betrayed when Harper and Eric strike a deal with Adler to preserve a reduced London operation by branding DVD and Rishi as disloyal. DVD is fired along with much of the London office, discovering his dismissal only when his security badge stops working.

Bukele stated in June 2019 that his government would no longer recognize Nicolás Maduro as the president of Venezuela, instead recognizing Juan Guaidó as Venezuela's legitimate president during Venezuela's presidential crisis. On 3 November of that year, he expelled Maduro-appointed Venezuelan diplomats from El Salvador. Bukele considers Maduro to be a dictator. Bukele rejected the results of the 2024 Venezuelan presidential election as a "fraud" ("fraude") and stated that he would not restore relations with Venezuela unless there were "real elections" ("elecciones de verdad"). Bukele refused to recognize the presidency of Manuel Merino in Peru in November 2020, calling Merino's government "putschist" ("golpista"). He and the Legislative Assembly denounced the results of the 2021 Nicaraguan general election, that were seen by several governments as fraudulent. El Salvador has abstained from resolutions critical of Nicaragua at the Organization of American States since 2022, with Bukele's government citing "non-interference" ("no injerencia") as justification. In 2024, El Salvador was the only country to abstain on an OAS resolution to condemn Ecuador for raiding the Mexican embassy in Quito to arrest former Ecuadorian vice president Jorge Glas.

Three types of Marines are featured in the game: the soldier will simply provide fire support for the player with a submachine gun, shotgun or machine gun, the combat medic is capable of healing the player and other non-player characters, while the engineer can cut through doors and remove obstacles, allowing the player and their squad to proceed unhindered. A selection of enemies from Half-Life populate the game, including alien creatures such as headcrabs and Vortigaunts. A variety of new alien non-player characters, labelled "Race X", appear as well. The player also encounters human opponents in the form of a detachment of black operations units who have been sent to destroy the base in the wake of the failure of the U.S. Marines to eliminate the alien threat. A limited selection of Half-Life's weaponry is allocated to the player to defend themselves with, although several new weapons such as a sniper rifle, combat knife and a variety of alien weaponry are also present.

==== Biomolecules ==== The isotopic composition of biomolecules preserved in the sedimentary record can be used as a proxy for paleoenvironment reconstructions. Since water is the main hydrogen source for photoautotrophs, the HIC of their biomass can be related to the composition of their growth water and thereby used to gain insight into some properties of ancient environments. Studying hydrogen isotopes can be very valuable, as hydrogen is more directly related to climate than other relevant stable isotope systems. However, hydrogen atoms bonded to oxygen, nitrogen, or sulfur are exchangeable with environmental hydrogen, which makes this system less straightforward [ref to earlier H exchange section]. To study the HIC of biomolecules, it is preferable to use compounds where the hydrogen is largely bound to carbon, and thus not exchangeable on experimental timescales. By this criterion, lipids are a much better subject for hydrogen isotope studies than sugars or amino acids. The net fractionation between source water and lipids is denoted εl/w:

Postprandial somnolence (colloquially known as food coma or after-meal dip) is a benign state of drowsiness or lassitude following a meal, a general state of sleepiness and low energy related to activation of the parasympathetic nervous system in response to mass in the gastrointestinal tract. While there are numerous theories surrounding this behavior, such as decreased blood flow to the brain, neurohormonal modulation of sleep through digestive coupled signaling, or vagal stimulation, very few have been explicitly tested. To date, human studies have loosely examined the behavioral characteristics of postprandial sleep, demonstrating potential shifts in EEG spectra and self-reported sleepiness. To date, the only clear animal models for examining the genetic and neuronal basis for this behavior are the fruit fly, the mouse, and the nematode Caenorhabditis elegans.

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.

How does CJC-1295 raise growth hormone levels?

It binds the growth hormone-releasing hormone receptor on pituitary somatotroph cells. Receptor activation raises cyclic AMP and promotes release of stored growth hormone granules. Because the peptide persists longer than natural releasing hormone, stimulation is prolonged rather than brief.

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