If you have been reading about incretin 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 2025-08-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
Clinical development of this compound followed earlier short-acting GLP-1 analogues that required frequent injection. Once-weekly subcutaneous formulations entered use after 2017, and an oral formulation using a permeation enhancer later became available. The oral version pairs the peptide with sodium N-(8-[2-hydroxybenzoyl] amino) caprylate, a carrier that improves uptake across the gastric epithelium. Interest has expanded from glycaemic control into weight management and metabolic liver disease. Regulatory status and approved indications differ between countries, and the product remains subject to ongoing safety monitoring.
Semaglutide is a synthetic peptide that acts as an agonist at the glucagon-like peptide-1 receptor. It is a structural analogue of human GLP-1(7-37), modified to resist enzymatic degradation by dipeptidyl peptidase-4. The peptide backbone contains alpha-aminoisobutyric acid at position 8, a substitution that stabilises the helix and slows cleavage. A fatty diacid side chain attached through a linker at lysine 34 promotes binding to serum albumin, which extends the circulating half-life. These two modifications together allow less frequent administration than native GLP-1 requires.
Activation of the GLP-1 receptor couples to Gs signalling and raises intracellular cyclic AMP in pancreatic beta cells. The resulting insulin release depends on prevailing glucose concentrations, so the effect is greater when glucose is elevated. Receptor engagement also suppresses glucagon secretion and slows gastric emptying, which flattens post-meal glucose excursions. In the central nervous system, signalling in hypothalamic and brainstem regions is associated with reduced appetite and lower energy intake. Studies continue to examine effects on cardiac, renal and hepatic endpoints; whether those benefits are independent of weight change remains an open question.
The semaglutide sequence is a 31-residue analogue of human GLP-1, altered at three positions relative to the parent hormone. Aminoisobutyric acid replaces alanine at position 8, arginine replaces lysine at position 34, and a lipophilic diacid is attached to lysine 26 through a short linker. These features are reported consistently in the structural literature. The position 8 substitution blocks recognition by dipeptidyl peptidase-4, while the attached chain drives strong, reversible association with a carrier protein in blood.
Receptor activation raises intracellular cyclic AMP through Gs coupling, which promotes glucose-dependent insulin release and suppresses glucagon secretion when blood glucose is elevated. Effects outside the pancreas include slower gastric emptying and altered appetite signalling in the hypothalamus and hindbrain. The relative contribution of each tissue to overall metabolic outcomes remains an area of active investigation. Central mechanisms in particular are inferred mainly from animal models and indirect human measures rather than direct observation.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C187H291N45O59 | Parent peptide; salt forms also reported |
| Molecular mass | about 4113.6 Da | Average mass of the free peptide |
| Peptide length | 31 amino acids | Backbone related to GLP-1(7-37) |
| Key substitution | Aib at position 8 | Blocks DPP-4 cleavage |
| Albumin binding | Via C-18 diacid side chain | Prolongs circulation time |
Semaglutide is a synthetic peptide analog of glucagon-like peptide-1 (GLP-1), a hormone released from intestinal L-cells after food intake. The compound belongs to the incretin mimetic class and acts at GLP-1 receptors distributed across pancreatic, gastrointestinal, cardiovascular, and central nervous system tissues. Compared with native GLP-1, the molecule carries structural changes that extend its activity from minutes to roughly one week. It is studied for glycemic control in type 2 diabetes and for weight management, and its effects on cardiovascular and other outcomes remain active research areas.
Receptor binding triggers G protein signaling that raises intracellular cyclic AMP in pancreatic beta cells. Insulin release follows in a glucose-dependent manner, so secretion increases when blood glucose is elevated and diminishes when it is not. The same signaling suppresses glucagon release from alpha cells and slows gastric emptying, which blunts the post-meal glucose rise. In the brain, receptor activation in regions such as the arcuate nucleus is associated with reduced appetite and lower energy intake. How much each of these effects contributes to overall weight change is not fully settled.
Semaglutide is a synthetic peptide analogue of glucagon-like peptide-1, a gut hormone released by intestinal L cells after food intake. The natural hormone acts on pancreatic and central receptors but is degraded within minutes by dipeptidyl peptidase-4 and other peptidases. Semaglutide belongs to the class of long-acting GLP-1 receptor agonists, a group distinguished by structural changes that slow breakdown and extend circulation time. Its development followed earlier short-acting analogues and reflects a general strategy in peptide drug design: preserve receptor activity while blocking proteolytic clearance.
Three structural changes define the molecule. At position 8 an alpha-aminoisobutyric acid residue replaces alanine, which blocks dipeptidyl peptidase-4 cleavage. At position 34 arginine replaces lysine, and at position 26 a lysine carries a C18 fatty diacid attached through a short linker. The fatty chain binds serum albumin, and this albumin association reduces renal filtration and enzymatic attack. The unchanged backbone retains the receptor contacts that produce signalling. The free base has the formula C187H291N45O59 and a molecular weight near 4114 daltons.
Receptor activation follows the canonical Gs pathway: binding increases intracellular cyclic AMP, which promotes protein kinase A activity. In pancreatic beta cells this amplifies glucose-dependent insulin release, so secretion rises when blood glucose is high and changes little when it is low. The same signalling suppresses glucagon release from alpha cells and slows gastric emptying. Receptors in the hypothalamus and brainstem are thought to contribute to reduced appetite and lower energy intake. Which of these effects dominates clinical outcomes remains an area of active study.
A meta-analysis provided preliminary evidence that men treated with supplements containing selenium, zinc, omega-3 fatty acids, coenzyme Q10 or carnitines reported improvements in total sperm count, concentration, motility, and morphology. A review concluded that omega-3 taken through supplements and diet might improve semen quality in infertile men. A 2021 review also supported selenium, zinc, omega-3 fatty acids, coenzyme Q10 or carnitines, but warned that "excessive use of antioxidants may be detrimental to the spermatic function and many of the over-the-counter supplements are not scientifically proven to improve fertility." There is low quality and insufficient evidence for the use of oral antioxidant supplements as a viable treatment for subfertile woman. A review provided evidence that taking dehydroepiandrosterone before starting an in vitro fertilization series may increase pregnancy rates and decrease miscarriage likelihood.
=== Medicine === Sodium calcium edetate, an EDTA derivative, is used to bind metal ions in the practice of chelation therapy, such as for treating mercury and lead poisoning. It is used in a similar manner to remove excess iron from the body. This therapy is used to treat the complication of repeated blood transfusions, as would be applied to treat thalassaemia.
Some species try to bite immediately. Some will use their heads as sledgehammers and literally smash an opponent, some will rush or swim toward the threat from a distance, even chasing the opponent onto land or galloping after it. The main weapon in all crocodiles is the bite, which can generate very high bite force. Many species also possess canine-like teeth. These are used primarily for seizing prey, but are also used in fighting and display.
The Banting Postdoctoral Fellowship Program is administered by the Canadian Institutes of Health Research, the Natural Sciences and Engineering Research Council of Canada, and the Social Sciences and Humanities Research Council of Canada. The fellowship provided up to two years of funding at $70,000 per year to researchers in health, natural sciences, engineering, social sciences and humanities.
Sources: en.wikipedia.org
=== Biomedical === Nanoscale particles are used in biomedical applications as drug carriers or imaging contrast agents in microscopy. Anisotropic nanoparticles are a good candidate in biomolecular detection. Moreover, nanoparticles for nucleic acid delivery offer an unprecedented opportunity to overcome some drawbacks related to the delivery, owing to their tunability with diverse physico-chemical properties, they can readily be functionalized with any type of biomolecules/moieties for selective targeting. Using nanoparticles in cancer treatment is being extensively researched. Certain characteristics of the tumor microenvironment, including leaky vasculature and poor lymphatic drainage, lead to the accumulation of NPs in the tumor. This is known as the enhanced permeability and retention (EPR) effect, and is a type of passive targeting. Additionally, ligands that bind to certain expressed or over-expressed receptors in the tumor microenvironment can be conjugated to the surface of nanoparticles to actively target the tumor. The accumulation of nanoparticles in the tumor can reduce adverse side effects, which is a major drawback of chemotherapy. In drug delivery, the acidic pH of the tumor microenvironment is often exploited to increase the release of the drug from pH-sensitive materials. Additionally, some NPs can generate heat under laser irradiation (photothermal therapy) or alternating magnetic field (magnetic hyperthermia), which can both kill cancer cells, and release drugs loaded in the nanoparticle.
As a second lieutenant in 1966, Noriega spent many months taking courses at the School of the Americas. The school was located at the United States Army's Fort Gulick in the Panama Canal Zone. Journalist John Dinges has suggested that Torrijos sent Noriega to the school to help him "shape up" and live up to Torrijos's expectations. Despite performing poorly in his classes, he was promoted to the rank of first lieutenant in 1966, and Torrijos found him a job as an intelligence officer in the "North Zone" of the National Guard. Shortly afterward, he returned to the School of the Americas for more training. At the school, Noriega participated in courses on infantry operations, counterintelligence, intelligence, and jungle warfare. He also took a course in psychological operations at Fort Bragg in North Carolina. Noriega's job required him to penetrate and disrupt the trade unions that had formed in the United Fruit Company's workforce, and he proved adept at this work. His new superior officer Boris Martínez was a fervent anti-communist, and enforced strict discipline on Noriega. Reports have suggested that he continued to pass intelligence to the U.S. during this period, about the plantation workers' activities. In 1967 the administration of U.S. President Lyndon B. Johnson concluded that Noriega would be a valuable asset, as he was a "rising star" in the Panamanian military. Later, as the de facto leader of Panama, Noriega maintained a close relationship with the School of the Americas, partly due to the school's presence in Panama.
== Litigation science == "Litigation science" describes analysis or data developed or produced expressly for use in a trial versus those produced in the course of independent research. This distinction was made by the U.S. 9th Circuit Court of Appeals when evaluating the admissibility of experts. This uses demonstrative evidence, which is evidence created in preparation of trial by attorneys or paralegals.
Sources: en.wikipedia.org
The movement for a single-island region started in the 1980s when officials of both provinces proposed a one-island, one-region unit. Negros Occidental and Negros Oriental are the only provinces in the Philippines situated in the same island but belonging to two different administrative regions with regional offices located in neighboring Panay and Cebu. The movement to unite the two provinces in Negros island was sustained in the 1990s and 2010s. The campaign for the creation of a region in Negros had gains when President Benigno Aquino III directed the Department of the Interior and Local Government (DILG) to study the establishment of a new region. with the government agency later endorsing the move. NEDA affirmed by saying that its studies show that the proposed region is economically viable. On May 29, 2015, President Aquino signed Executive Order 183, which created the Negros Island Region. It separated Negros Occidental and its capital Bacolod from Western Visayas (Region VI) and Negros Oriental from Central Visayas (Region VII) to form the island region, which made the total number of regions of the Philippines into 18.
It is a member of the family of heme-containing peroxidases. Heme peroxidases catalyse the hydrogen peroxide-dependent oxidation of a wide range of different, usually organic, substrates in biology. This enzyme belongs to the family of oxidoreductases, specifically those acting on a peroxide as acceptor (peroxidases). The systematic name of this enzyme class is L-ascorbate:hydrogen-peroxide oxidoreductase. Other names in common use include L-ascorbic acid peroxidase, L-ascorbic acid-specific peroxidase, ascorbate peroxidase, and ascorbic acid peroxidase. This enzyme participates in the ascorbate and aldarate metabolism. APXs are important in cellular antioxidant networks in photosynthetic organisms; they are the primary component of the ascorbate-glutathione cycle and are important for peroxide scavenging and redox signaling.
Pauling did, however, work on research for the military. He was a principal investigator on 14 OSRD contracts. The National Defense Research Committee called a meeting on October 3, 1940, wanting an instrument that could reliably measure oxygen content in a mixture of gases, so that they could measure oxygen conditions in submarines and airplanes. In response Pauling designed the Pauling oxygen meter, which was developed and manufactured by Arnold O. Beckman, Inc. After the war, Beckman adapted the oxygen analyzers for use in incubators for premature babies. In 1942, Pauling successfully submitted a proposal on "The Chemical Treatment of Protein Solutions in the Attempt to Find a Substitute for Human Serum for Transfusions". His project group, which included Joseph B. Koepfli and Dan H. Campbell, developed a possible replacement for human blood plasma in transfusions: polyoxy gelatin (Oxypolygelatin). Other wartime projects with more direct military applications included work on explosives, rocket propellants and the patent for an armor-piercing shell. In October 1948, Pauling, along with Lee A. DuBridge, William A. Fowler, Max Mason, and Bruce H. Sage, was awarded a Presidential Medal for Merit by President Harry S. Truman. The citation credits him for his "imaginative mind", "brilliant success", and "exceptionally meritorious conduct in the performance of outstanding services". In 1949, he served as president of the American Chemical Society.
Sources: en.wikipedia.org
It belongs to the incretin mimetic class and acts as a long-acting glucagon-like peptide-1 receptor agonist. The class includes several peptides with different half-lives and routes of administration.
The side chain enables reversible binding to albumin in the bloodstream, which protects the peptide from rapid renal clearance. This extends the interval between administrations compared with unmodified GLP-1.
No. It shares much of the native sequence but carries substitutions and an added side chain. These changes increase stability against enzymatic breakdown.
It is a synthetic peptide of 31 amino acids, built to resemble the natural incretin hormone GLP-1. Because of its size and composition it is handled analytically like other therapeutic peptides, using chromatographic and mass spectrometric methods rather than the techniques typical of small organic drugs.