GRF(1-29) 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 2026-06-29. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | Analog of growth hormone-releasing hormone |
| Chain length | 29 amino acids | Based on the GRF(1-29) fragment |
| Appearance | White to off-white lyophilized powder | Common research supply form |
| Solubility | Soluble in water and aqueous buffers | Powder requires reconstitution before use |
| Typical storage | −20 °C or below | Kept away from light and moisture |
== Further reading == Moskin, Julia (August 19, 2014). "Brisket Is Worth the Wait". The New York Times. Retrieved March 17, 2015. Green, Aliza (2005). Field Guide to Meat. Philadelphia: Quirk Books. ISBN 1-931686-79-3.
== Use in health == The primary usage of whey protein supplements is for muscle growth and development. Eating whey protein supplements before exercise will not assist athletic performance, but it will enhance the body's protein recovery and synthesis after exercise because it increases the free amino acids in the body's free amino acid pool. The antioxidant activity of whey protein helps to reduce oxidative stress associated with hypothyroidism. In 2010, a panel of the European Food Safety Authority (EFSA) panel examined the effects of whey protein on weight loss (via both fat loss and increased satiety) and strength and muscle building. The panel concluded that there's no evidence supporting any weight loss claims and that whey protein is roughly as effective for building strength, muscle and lean body mass as other protein sources. Although whey proteins are responsible for some milk allergies, the major allergens in milk are the caseins.
Concurrently, a line of work led by Mary Higby Schweitzer, Jack Horner, and colleagues reported various occurrences of preserved soft tissues and proteins within dinosaur bone fossils. Various mineralized structures that likely represented red blood cells and collagen fibres had been found by Schweitzer and others in tyrannosaurid bones as early as 1991. However, in 2005, Schweitzer and colleagues reported that a femur of Tyrannosaurus preserved soft, flexible tissue within, including blood vessels, bone matrix, and connective tissue (bone fibers) that had retained their microscopic structure. This discovery suggested that original soft tissues could be preserved over geological time, with multiple mechanisms having been proposed. Later, in 2009, Schweitzer and colleagues reported that a Brachylophosaurus femur preserved similar microstructures, and immunohistochemical techniques (based on antibody binding) demonstrated the presence of proteins such as collagen, elastin, and laminin. Both specimens yielded collagen protein sequences that were viable for molecular phylogenetic analyses, which grouped them with birds as would be expected. The extraction of fragmentary DNA has also been reported for both of these fossils, along with a specimen of Hypacrosaurus. In 2015, Sergio Bertazzo and colleagues reported the preservation of collagen fibres and red blood cells in eight Cretaceous dinosaur specimens that did not show any signs of exceptional preservation, indicating that soft tissue may be preserved more commonly than previously thought.
. It is unitless. A "high-resolution" mass analyzer typically has resolution >1 million. Concretely, that means it can resolve two peaks at ~1 kDa, differing by just ~1 mDa. The absolute accuracy is the ratio of the m/z measurement error to the true m/z. It is defined as
Epistles 13–14 of the first part of the Epistles of Wisdom focus on Jesus, detailing his ministry, his crucifixion by the Jews, and his descent from the cross. According to these epistles, Hamza bin Ali took him down from the cross and allowed him to return to his family, with the aim of preparing people to preach his religion. The epistle titled "Excuses and Warnings" foretells that, as a sign of the end times, Messiah Jesus "the son of Joseph and Mary", will appear in Egypt. The Jews will seize control of Jerusalem and seek revenge on the inhabitants of both Jerusalem and Acre. Subsequently, Messiah Jesus will expel the Jews from Jerusalem, and Christians will dominate Muslims until the Day of Judgment, when the divine Al-Hakim bi-Amr Allah returns to judge humanity. The author of the epistle "The Report of the Jewish and Christians" (Khabar al-Yahud wal Nasara), part of first volume of the Epistles of Wisdom, appears to have been a Druze individual. The account itself identifies him as Hamza ibn Ali, a supporter of al-Hakim's divinity and the founder of the Druze faith. Hamza ibn Ali reportedly died after al-Hakim's disappearance in 1021. In the 18th century, the Orientalist Jean Michel de Venture de Paradis mentioned obtaining a manuscript discovered in a Druze village. This manuscript contained, among other things, a description of a dialogue between al-Hakim and leaders of the Christian and Jewish communities. Additionally, it included eight letters written by al-Hakim's lieutenant, Hamza ibn Ali, with the final one titled "The Report of the Jewish and Christians".
Sources: en.wikipedia.org
To reduce the cost to the military of maintaining stockpiles of certain pharmaceuticals, the United States Department of Defense (DoD) and the Food and Drug Administration (FDA) operate a joint initiative known as the Shelf Life Protection Program (SLEP), which evaluates the long-term effectiveness of medications stockpiled by the DoD and other government agencies. Under the program, medications are tested for safety and stability for extended periods of time in controlled storage conditions. In many cases, medications tested were found to be effective for years past their printed expiry dates; a 2006 study by the Journal of Pharmaceutical Sciences found that two-thirds of 122 medications tested through SLEP remained effective for an average of at least four additional years. In 2016, the DoD reported that the program had helped save the department US$2.1 billion on replacing stockpiled medications. While testing and stability assessment found that 88% of the lots were effective at least one year after their expiration date, with an average extension of 66 months, the additional stability period was very variable. For antibiotics studied, the mean extension for ciprofloxacin was 55 months, and for amoxicillin 23 months.
The Golden Gate assembly protocol was defined by Engler et al. 2008 to define a DNA assembly method that would give a final construct without a scar sequence, while also lacking the original restriction sites. This allows the protein to be expressed without containing unwanted protein sequences which could negatively affect protein folding or expression. By using the BsaI restriction enzyme that produces a 4 base pair overhang, up to 240 unique, non-palindromic sequences can be used for assembly. Plasmid design and assembly In Golden Gate cloning, each DNA fragment to be assembled is placed in a plasmid, flanked by inward facing BsaI restriction sites containing the programmed overhang sequences. For each DNA fragment, the 3' overhang sequence is complementary to the 5' overhang of the next downstream DNA fragment. For the first fragment, the 5' overhang is complementary to the 5' overhang of the destination plasmid, while the 3' overhang of the final fragment is complementary to the 3' overhang of the destination plasmid. Such a design allows for all DNA fragments to be assembled in a one-pot reaction (where all reactants are mixed together), with all fragments arranged in the correct sequence. Successfully assembled constructs are selected by detecting the loss of function of a screening cassette that was originally in the destination plasmid. MoClo and Golden Braid The original Golden Gate Assembly only allows for a single construct to be made in the destination vector .
=== Sources === Altringham, J. D. (2011). Bats: From Evolution to Conservation. Oxford University Press. ISBN 978-0-19-920711-4. Fenton, M. B. (2001). Bats. Checkmark Books. ISBN 978-0-8160-4358-3. Fenton, M. B.; Simmons, N. B. (2015). Bats: A World of Science and Mystery. University of Chicago Press. ISBN 978-0-226-06512-0. Neuweiler, Gerhard (2000). The Biology of Bats. Oxford University Press. ISBN 978-0-19-509950-8. Laird, Tessa (2018). Bat. Reaktion Books. ISBN 978-1-78023-937-8.
== Discovery == Collagen XXIII was first identified and isolated from rat prostate carcinoma cells by Jacqueline Banyard, Lere Bao and Bruce R. Zetter in 2003. They also identified this protein in human tissue. They concluded that at the nucleotide level, human and rat collagen XXIII alpha 1 show 76% identity. Furthermore, cellular localization of collagen XXIII was determined by immunofluorescence staining, using an antibody that recognizes the carboxyl terminus of the protein. It was demonstrated that the carboxyl terminus of collagen XXIII is present on the cell surface.
Corneal abrasion – a medical condition involving the loss of the surface epithelial layer of the eye's cornea as a result of trauma to the surface of the eye. Corneal dystrophy – a condition in which one or more parts of the cornea lose their normal clarity due to a buildup of cloudy material. Corneal ulcer – an inflammatory or infective condition of the cornea involving disruption of its epithelial layer with involvement of the corneal stroma. Corneal neovascularization – excessive ingrowth of blood vessels from the limbal vascular plexus into the cornea, caused by deprivation of oxygen from the air. Fuchs' dystrophy – cloudy morning vision. Keratitis – inflammation of the cornea. Keratoconus – a degenerative disease, the cornea thins and changes shape to be more like a cone. Corneal foreign body – a foreign object present in the cornea, one of the most common preventable occupational hazards.
Sources: en.wikipedia.org
Examples of primary intention include: well-repaired lacerations, well reduced bone fractures, healing after flap surgery. Early removal of dressings from clean or clean-contaminated wounds does affect primary healing of wounds.
=== Biological === Thorium is odourless and tasteless. The chemical toxicity of thorium is low because thorium and its most common compounds (mostly the dioxide) are poorly soluble in water, precipitating out before entering the body as the hydroxide. Some thorium compounds are chemically moderately toxic, especially in the presence of strong complex-forming ions such as citrate that carry the thorium into the body in soluble form. If a thorium-containing object has been chewed or sucked, it loses 0.4% of thorium and 90% of its dangerous daughters to the body. Three-quarters of the thorium that has penetrated the body accumulates in the skeleton. Absorption through the skin is possible, but is not a likely means of exposure. Thorium's low solubility in water also means that excretion of thorium by the kidneys and faeces is rather slow. Tests on the thorium uptake of workers involved in monazite processing showed thorium levels above recommended limits in their bodies, but no adverse effects on health were found at those moderately low concentrations. No chemical toxicity has yet been observed in the tracheobronchial tract and the lungs from exposure to thorium. People who work with thorium compounds are at a risk of dermatitis. It can take as much as thirty years after the ingestion of thorium for symptoms to manifest themselves. Thorium has no known biological role. However, a study by Tonietti et al. showed that some microorganisms can mobilize thorium through bioleaching processes.
=== "The Dark Alliance" === In 1996, the journalist Gary Webb published a series of articles for the San Jose Mercury News tying the Reagan administration to the trafficking of illegal narcotics into the United States. The three-part expose by Webb, "The Dark Alliance," claimed that in an effort to support the Sandinista National Liberation Front (FDN) financially, the CIA supported narcotics trafficking into the US by top members of the Nicaraguan rebel group, the Contras. Webb alleged that the fallout from the operation was the large scale spread of the crack epidemic in the United States. A California-based drug dealer, "Freeway," Rick Ross testified that Norwin Meneses and Danillo Blandon Reyes, two members of the FDN, supplied him with cocaine for much of the 1980s. He testified that at its peak, the drug ring operated from California to Michigan and as far south as Louisiana. The State Department knew of the operation and interfered with local police investigation to prevent the prosecution of FDN-linked trafficking. In 1990 Reyes testified that his "cocaine sales were for a time C.I.A. approved." Blandón testified that the CIA notified him of a raid on his home in 1986. Neither Meneses or Blandón ever received prison sentences for their roles in the scandal. The response to Webb's writings were mixed. Journalists from both The Washington Post and The Los Angeles Times credited Webb with an important piece of journalism. David Corn of The Washington Post wrote that Webb "deserves credit for pursuing an important piece of recent history and forcing the C.I.A.
Lambert (2026) reevaluates the affinites of "Platybelodon" barnumbrowni from the Late Miocene of Nebraska (United States), transferring the species to the genus Protanancus (the first record of the genus from North America), as well as describing "Serbelodon" burnhami and an unnamed taxon from the Bone Valley of Florida as sharing affinities with Protanancus. Armaroli et al. (2026) reconstruct the ecology and habitat use of straight-tusked elephants from the Neumark-Nord site (Germany) on the basis of the study of the strontium isotopic composition of their remains and on the basis of proteomic analysis, reporting evidence indicating that the studied elephant assemblage included both male and female individuals from geographically separated populations that migrated to the lake basins of Neumark-Nord, and evidence of seasonal mobility of the studied individuals, including probable evidence of two male individuals dwelling in mountainous areas within 300 km of Neumark-Nord. Farrell et al. (2026) identify fossil material of a straight-tusked elephant from the mid-Pleistocene North Bridge Acheulian site north of Gesher Benot Ya'aqov (Israel), and interpret its tooth wear and isotopic composition of its tooth enamel, coupled with the studies of local palynological assemblages and climatic reconstructions, as indicative of a mixed-feeding strategy of the studied individual, as well as indicating that it lived in a mosaic woodland-wetland habitat with a Mediterranean climate. Kusaka et al.
Sources: en.wikipedia.org
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.
DAC stands for drug affinity complex, a chemical group that binds the peptide to serum albumin. The binding slows clearance and lengthens the time the molecule stays in plasma compared with the unmodified analog.
Because two distinct molecules are discussed under one informal label. The albumin-binding version clears over several days, while the form without that group clears within roughly half an hour. Mixing results from both creates inconsistent figures.
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.