If you have been reading about MOD GRF 1-29 and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-09-26. Where a claim depends on a specific study, the study is described rather than over-claimed.
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 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.
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.
Two related peptides circulate under the CJC-1295 label, and they differ mainly in how long they persist in circulation. The version carrying a drug affinity complex includes a maleimidopropionic acid linker that forms a covalent bond with serum albumin. The other version, usually written as modified GRF(1-29) or tetrasubstituted GRF(1-29), lacks that linker and is cleared quickly. Mixing the two produces inconsistent readings of published half-life values, because the linker rather than the receptor-facing sequence drives most of the difference.
| Property | Value | Notes |
|---|---|---|
| Molecular weight (with DAC) | ~3647 Da | Calculated from the full amino acid sequence |
| Molecular weight (without DAC) | ~3368 Da | Mod GRF(1-29) variant |
| Appearance | White lyophilized powder | Typical form supplied for research |
| Solubility | Soluble in water | Dissolves in aqueous buffers |
| Receptor target | GHRH receptor | Expressed on pituitary somatotroph cells |
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.
Lyophilized material is typically stored at minus twenty degrees Celsius or lower. Keeping the vial dry and protected from light preserves peptide integrity. Repeated freeze-thaw cycles can cause aggregation or loss of activity. Once dissolved, solutions are generally kept at two to eight degrees Celsius. Stability data for reconstituted solutions vary, and long-term behavior is not fully established. Working aliquots reduce the number of times a stock container is opened.
Reverse-phase high-performance liquid chromatography is the standard tool for purity assessment. The technique separates the target peptide from truncated or modified byproducts. Mass spectrometry confirms molecular weight and supports sequence verification. Electrospray ionization and matrix-assisted laser desorption are both used. Amino acid analysis provides an independent check on composition. Purity values are commonly reported as area percentage from the chromatogram. Residual trifluoroacetate and water content are also measured in many quality programs.
Batch-to-batch consistency depends on solid-phase peptide synthesis and subsequent purification. Coupling efficiency, resin choice, and cleavage conditions all affect the final profile. Counter-ion content and moisture can shift the apparent mass of a batch. Documentation typically includes a certificate of analysis with chromatograms and spectra. Independent verification by a second laboratory is sometimes requested. Whether a given certificate reflects the actual vial contents depends on chain of custody. Analytical methods themselves carry uncertainty that should be stated alongside results.
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.
The I1 receptor appears to be a G protein-coupled receptor that is localized on the plasma membrane. It may be coupled to PLA2 signalling and thus prostaglandin synthesis. In addition, activation inhibits the sodium-hydrogen antiporter and enzymes of catecholamine synthesis are induced, suggesting that the I1 receptor may belong to the neurocytokine receptor family, since its signaling pathways are similar to those of interleukins. It is found in the neurons of the reticular formation, the dorsomedial medulla oblongata, adrenal medulla, renal epithelium, pancreatic islets, platelets, and the prostate. They are notably not expressed in the cerebral cortex or locus coeruleus. Animal research suggests that much of the antihypertensive action of imidazoline drugs such as clonidine is mediated by the I1 receptor. In addition, I1 receptor activation is used in ophthalmology to reduce intraocular pressure. Other putative functions include promoting Na+ excretion and promoting neural activity during hypoxia.
P2Y purinoceptor 13 is a protein that in humans is encoded by the P2RY13 gene. The product of this gene, P2Y13, belongs to the family of G-protein coupled receptors. This family has several receptor subtypes with different pharmacological selectivity, which overlaps in some cases, for various adenosine and uridine nucleotides. This receptor is activated by ADP. Two transcript variants encoding the same protein have been identified for this gene.
== External links == Along the ancient silk routes: Central Asian art from the West Berlin State Museums, an exhibition catalog from The Metropolitan Museum of Art (fully available online as PDF), which contains material from Kizil Caves The Oases of the Northern Tarim Basin Revealing the Beauty of the Kizil Caves "Sackler Gallery exhibition in 2002– Caves as Canvas: Hidden Images of Worship Along the Ancient Silk Road". Smithsonian Institution. Archived from the original on 2003-01-03. Retrieved 2012-08-11. Kizil Paintings in the Hermitage Museum Kizil Paintings in the Dahlem Museum Archived 2024-12-06 at the Wayback Machine
Sources: en.wikipedia.org
=== Without feline features === In ancient Assyria, bas-reliefs of shedu bulls with the crowned bearded heads of kings guarded the entrances of temples. Many Greek mythological creatures who are archaic survivals of previous mythologies with respect to the classical Olympian mythology, like the centaurs, are similar to the Sphinx.
== History == The suspensory muscle of the duodenum was first named in 1853 by Václav Treitz, as the musculus suspensorius duodeni (in Latin), and described as consisting of a lower muscular portion with a broad base, and an upper tendinous portion blending with connective tissue around the origins of the superior mesenteric and coeliac arteries. It is commonly termed the ligament of Treitz by clinicians and as the suspensory muscle of the duodenum by anatomists. It has also been likened to "a polar ice cap ... a structure that many refer to but few have seen."
Specifically when set up in a loop with a buffering liquid between the incoming and outgoing fluid running in a circuit, and with active transport pumps on the outgoing fluid's tubes, the system is called a countercurrent multiplier, enabling a multiplied effect of many small pumps to gradually build up a large concentration in the buffer liquid. Other countercurrent exchange circuits where the incoming and outgoing fluids touch each other are used for retaining a high concentration of a dissolved substance or for retaining heat, or for allowing the external buildup of the heat or concentration at one point in the system. Countercurrent exchange circuits or loops are found extensively in nature, specifically in biologic systems. In vertebrates, they are called a rete mirabile, originally the name of an organ in fish gills for absorbing oxygen from the water. It is mimicked in industrial systems. Countercurrent exchange is a key concept in chemical engineering thermodynamics and manufacturing processes, for example in extracting sucrose from sugar beet roots. Countercurrent multiplication is a similar but different concept where liquid moves in a loop followed by a long length of movement in opposite directions with an intermediate zone. The tube leading to the loop passively building up a gradient of heat (or cooling) or solvent concentration while the returning tube has a constant small pumping action all along it, so that a gradual intensification of the heat or concentration is created towards the loop.
O'Mahoney (1907), United States senator from Wyoming James W. Mott (1909), U.S. congressman from Oregon Emanuel Celler (1910), 39th dean of the United States House of Representatives; U.S. congressman from New York William Langer (1910), United States senator and governor of North Dakota Laurence Steinhardt (1913), former U.S. ambassador to Sweden, Peru, the Soviet Union, Turkey, Czechoslovakia and Canada; the first U.S. ambassador to be killed in office Henry Frank Holthusen (1915), lawyer, diplomat, U.S. ambassador to Czechoslovakia nominee Samuel Irving Rosenman (1915), 1st White House counsel to presidents Franklin D. Roosevelt and Harry S. Truman, name partner of Katten Muchin Rosenman Frederic René Coudert Jr. (1918), U.S. congressman from New York Harold F. Linder (1921), president of the Export-Import Bank of the United States 1961–1968; former U.S ambassador to Canada Arthur Levitt Sr. (1921), longest-serving New York state comptroller; father of Arthur Levitt, chairman of the United States Securities and Exchange Commission Joseph Zaretzki (1922), majority leader of the New York State Senate 1966–1974 Louis M. Rousselot (1923), assistant secretary of defense for health and environment 1970–1971 Joseph Campbell (1924), fourth comptroller general of the United States Arthur F. Burns (1925), chairman of the Federal Reserve and U.S. ambassador to West Germany Bernard M. Shanley (1925), White House counsel 1953–1955; secretary to the president of the United States under Dwight D. Eisenhower 1955–1957 Joseph F.
Sources: en.wikipedia.org
=== Humans and other mammals === Humans and other mammals have chitinase and chitinase-like proteins that can degrade chitin; they also possess several immune receptors that can recognize chitin and its degradation products, initiating an immune response. Chitin is sensed mostly in the lungs or gastrointestinal tract where it can activate the innate immune system through eosinophils or macrophages, as well as an adaptive immune response through T helper cells. Keratinocytes in skin can also react to chitin or chitin fragments.
Theravadins in general eat meat. If Buddhist monks "see, hear or know" a living animal was killed specifically for them to eat, they must refuse it or else incur an offense. However, this does not include eating meat which was given as alms or commercially purchased. In the Theravada canon, Shakyamuni Buddha did not make any comment discouraging them from eating meat (except specific types, such as human, elephant, horse, dog, snake, lion, tiger, leopard, bear, and hyena flesh) but he specifically refused to institute vegetarianism in his monastic code when a suggestion had been made. In several Sanskrit texts of Mahayana Buddhism, Buddha instructs his followers to avoid meat. However, each branch of Mahayana Buddhism selects which sutra to follow, and some branches, including the majority of Tibetan and Japanese Buddhists, actually do eat meat. Meanwhile, Chinese, Korean, Vietnamese Buddhism (in some sectors of East Asian Buddhism) monks and nuns are expected to abstain from meat, and traditionally, to abstain from eggs and dairy as well. Different Buddhist traditions have differing teachings on diet, which may also vary for ordained monks and nuns compared to others. Many interpret the precept "not to kill" to require abstinence from meat, but not all. In Taiwan, su vegetarianism excludes not only all animal products but also vegetables in the allium family (which have the characteristic aroma of onion and garlic): onion, garlic, scallions, leeks, chives, or shallots.
In exclusive arrangements, the distributor is expected to work closely with the manufacturer and add value to the product through service level, after sales care or client support services. Another definition of exclusive arrangement is an agreement between a supplier and a retailer granting the retailer exclusive rights within a specific geographic area to carry the supplier's product. Summary of strategic approaches to distribution
Sources: en.wikipedia.org
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.
The maleimide group forms a covalent link with albumin, an abundant blood protein. This attachment slows clearance, so a single administration persists much longer than the unmodified peptide. The feature is the main reason the two variants are handled differently in study design.
It is not an approved therapeutic product in major regulatory jurisdictions. It appears in research chemical catalogs and scientific literature rather than pharmacy shelves. Clinical development was limited and did not reach approval.
Natural GHRH is degraded quickly by dipeptidyl peptidase-4 and related enzymes, giving it a half-life measured in minutes. CJC-1295 carries substitutions that slow that breakdown, so it stays intact longer. Both act at the same pituitary receptor and produce the same class of signal.