This is a working overview of CJC-1295, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-08-31 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular weight, DAC form | About 3647 Da | Varies with salt form |
| Molecular weight, non-DAC form | About 3358 Da | MOD GRF(1-29) |
| Solubility class | Water soluble | Also dissolves in polar solvents |
| Reported half-life, DAC form | About five to eight days | Values from human studies |
| Common synonyms | CJC-1295; MOD GRF(1-29) | Name depends on variant |
CJC-1295 belongs to a family of synthetic peptides modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound is built from the first twenty-nine amino acids of the natural human sequence, a fragment that retains full receptor binding capacity. Native growth hormone-releasing hormone is degraded quickly in circulation, so the fragment alone has limited practical value. Early work therefore focused on chemical modifications that preserve receptor binding while slowing enzymatic breakdown. The result is a molecule described in the literature as a long-acting analog of the natural hormone.
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.
=== Side-effects === Although patients at high risk of bleeding were excluded from the phase III clinical study (PROWESS), 25% of patients treated with drotrecogin and 18% of those receiving placebo experienced at least one bleeding event (principally ecchymoses or GI bleeding) during the 28-day study period. During treatment, serious bleeding events (e.g., intracranial hemorrhage, any life-threatening bleeding event, any bleeding event requiring administration of at least 3 units of packed red blood cells daily for 2 consecutive days) occurred in 2.4% of patients treated with drotrecogin and in 1% of those receiving placebo. No significant differences between geriatric patients and younger patients regarding bleeding events in the drotrecogin group were found. No non-bleeding side-effects were observed. A second study, encompassing approximately 1700 adult patients, was completed in 2011 and showed a comparable side-effect profile.
=== 1849–1950: Early history === Pfizer was founded in 1849 as Charles Pfizer & Company by Charles Pfizer and Charles F. Erhart, two cousins who had immigrated to the United States from Ludwigsburg, Germany. The business produced chemical compounds, and was headquartered on Bartlett Street in Williamsburg, Brooklyn, where it produced an antiparasitic called santonin. This was an immediate success, although it was production of citric acid that led to Pfizer's growth in the 1880s. Pfizer continued to buy property in the area (by now the Williamsburg district of the city of Brooklyn, New York and beginning in 1898, the City of Greater New York) to expand its lab and factory, retaining offices on Flushing Avenue until the 1960s; the Brooklyn plant ultimately closed in 2009. Following its success with citric acid, Pfizer (at the now-demolished 295 Washington Avenue) and Erhart (at 280 Washington Avenue) established their main residences in the nearby Clinton Hill district, known for its concentration of Gilded Age wealth. In 1881, Pfizer moved its administrative headquarters to 81 Maiden Lane in Manhattan, presaging the company's expansion to Chicago, Illinois, a year later. By 1906 sales exceeded $3 million. World War I caused a shortage of calcium citrate. Pfizer imported the compound from Italy for the manufacture of citric acid, and due to the disruption in supply, the company began a search for an alternative. They found this in the form of a fungus capable of fermenting sugar to citric acid.
=== Canada, United States, Mexico === Ractopamine use as a feed additive is authorized in the United States, Canada, and Mexico. In the US, ractopamine is allowed to be used at a feed concentration of 5–20 mg/kg feed for finishing pigs and in dosages of 5–10 mg/kg feed for finishing pigs heavier than 109 kg. The maximum residue limit for ractopamine for meat in the US is 50 parts per billion (ppb), or five times the standard set by the Codex Alimentarius. Ractopamine was approved by the FDA in 1999 for use in swine, in 2003 for use in cattle, and in 2008 for use in turkeys. In 2015, the USDA approved of a new label, "No ractopamine — a beta-agonist growth promotant" to be used. The Canadian Food Inspection Agency (CFIA) maintains the Canadian Ractopamine-Free Pork Certification Program (CRFPCP) so that Canadian exports to Asian countries are not disallowed by their authorities. Hundreds of commercial feed facilities, including some from overseas, are enrolled in the CRFPCP, a programme that is essentially based on self-certification and backed up by a randomized testing policy. Currently, the label for USDA organic means no synthetic compounds can be used other than those on the list of allowed synthetics; therefore, ractopamine would not be allowed in certified organic production.
Sources: en.wikipedia.org
== Discovery == In 1902, Léon Teisserenc de Bort from France and Richard Assmann from Germany, in separate but coordinated publications and following years of observations, published the discovery of an isothermal layer at around 11–14 km (6.8-8.7 mi), which is the base of the lower stratosphere. This was based on temperature profiles from mostly unmanned and a few manned instrumented balloons.
== Environmental contamination == BPF is pervasive in the environment, appearing in river water, drinking water, and agricultural soil samples. Biodegradation appears to be the most promising route for removal of BPA and related bisphenols. One degradation process converts BPA to the corresponding benzophenone (HOC6H4)2CO, which is relatively labile.
=== Traditional medicine and research === The bark, sap, roots, leaves, seeds, and flowers are used in traditional medicine. Research has examined how it might affect blood lipid profiles and insulin secretion. Extracts from leaves contain various polyphenols, which are under basic research to determine their potential effects in humans. Despite considerable preliminary research to determine if moringa components have bioactive properties, no high-quality evidence has been found to indicate that it has any effect on health or diseases.
Sources: en.wikipedia.org
== Committees == CLSI documents are developed by committees consisting of experts in medical testing or related aspects. Each CLSI committee produces consensus documents related to a specific discipline.
PKS, carbon-carbon bond formation through Claisen condensation reaction NRPs, the C domain catalyzes the amide bond formation between the amino acid it adds to the chain (on the PCP of one module) and the nascent peptide (on the PCP of the next module).
Another possibility is that the forelimbs held struggling prey while it was killed by the tyrannosaur's enormous jaws. This hypothesis may be supported by biomechanical analysis. T. rex forelimb bones exhibit extremely thick cortical bone, which has been interpreted as evidence that they were developed to withstand heavy loads. The biceps brachii muscle of an adult T. rex was capable of lifting 199 kilograms (439 lb) by itself; other muscles such as the brachialis would work along with the biceps to make elbow flexion even more powerful. The M. biceps muscle of T. rex was 3.5 times as powerful as the human equivalent. A T. rex forearm had a limited range of motion, with the shoulder and elbow joints allowing only 40 and 45 degrees of motion, respectively. In contrast, the same two joints in Deinonychus allow up to 88 and 130 degrees of motion, respectively, while a human arm can rotate 360 degrees at the shoulder and move through 165 degrees at the elbow. The heavy build of the arm bones, strength of the muscles, and limited range of motion may indicate a system evolved to hold fast despite the stresses of a struggling prey animal. In the first detailed scientific description of Tyrannosaurus forelimbs, paleontologists Kenneth Carpenter and Matt Smith dismissed notions that the forelimbs were useless or that Tyrannosaurus was an obligate scavenger. The idea that the arms served as weapons when hunting prey have also been proposed by Steven M.
== History == The first reported chemical synthesis of HMB was published in 1877 by the Russian chemists Michael and Alexander Zaytsev. HMB was isolated from the bark of Erythrophleum couminga (a Madagascan tree) in 1941 by Leopold Ružička. The earliest reported isolation of HMB as a human metabolite was by Tanaka and coworkers in 1968 from a patient with isovaleric acidemia. The effects of HMB on human skeletal muscle were first discovered by Steven L. Nissen at Iowa State University in the mid-1990s. Nissen founded a company called Metabolic Technologies, Inc. (MTI) around the time of his discovery, which later acquired six HMB-related patents that the company has used to license the right to manufacture and incorporate HMB into dietary supplements. When it first became available commercially in the late 1990s, HMB was marketed solely as an exercise supplement to help athletes and bodybuilders build muscle. MTI subsequently developed two HMB-containing products, Juven and Revigor, to which Abbott Nutrition obtained the market rights in 2003 and 2008 respectively. Since then, Abbott has marketed Juven as a medical food and the Revigor brand of HMB as an active ingredient in food products (e.g., certain formulations of Ensure) and other medical foods (e.g., certain formulations of Juven).
Sources: en.wikipedia.org
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.
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.
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.
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.