This is a working overview of incretin, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-08-12. Anything still debated is marked as such rather than presented as settled.
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.
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.
The company that developed the compound filed it as a long-acting analogue, and it gained first approval in 2017 for type 2 diabetes. Later authorisations from several regulators extended the indication to chronic weight management, and the World Health Organization added the glucagon-like peptide-1 receptor agonist drug class to its model list of essential medicines in 2023. Production uses solid-phase peptide synthesis followed by side-chain conjugation and chromatographic purification. Supply constraints and cost differences across regions are well documented. Literature on long-term outcomes continues to grow, with many trials reporting surrogate endpoints rather than hard clinical endpoints.
Semaglutide is a synthetic peptide of thirty-one amino acids that shares roughly ninety-four percent sequence identity with human glucagon-like peptide-1. Two substitutions resist enzymatic cleavage by dipeptidyl peptidase-4, and a fatty diacid side chain attached through a linker promotes binding to serum albumin. That albumin binding slows renal clearance and extends the circulating half-life from minutes to approximately one week. The structural changes are well established in the published literature. Whether the same modifications affect receptor signalling bias in ways that matter clinically remains an open question.
Pharmacological activity arises from agonism at the glucagon-like peptide-1 receptor, a G protein-coupled receptor expressed in the pancreas, the gastrointestinal tract, and the brainstem. Receptor activation raises intracellular cyclic adenosine monophosphate and enhances insulin release in a glucose-dependent manner, an effect that diminishes when blood glucose concentration is low. Other effects include slowed gastric emptying and hypothalamic satiety signalling. These pathways are described well. Receptor desensitisation rates across tissues, relative to the endogenous hormone, are still under investigation, and reported findings differ between laboratories.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C187H291N45O59 | free base, without counter-ion |
| Molecular weight | About 4114 Da | peptide backbone plus attached lipid chain |
| Plasma half-life | About 165 hours | supports once-weekly dosing in humans |
| Plasma protein binding | Greater than 99 percent | attributed mainly to serum albumin |
| Receptor target | GLP-1 receptor | Gs-coupled, raises intracellular cyclic AMP |
Large randomised trials in adults with type 2 diabetes and in adults with obesity have reported reductions in body weight and improvements in several cardiovascular risk markers. One outcome trial found a lower incidence of major adverse cardiovascular events in participants with diabetes and established cardiovascular disease. Gastrointestinal effects such as nausea and vomiting are the most frequently reported adverse events and often diminish over time. Changes in lean body mass during weight loss are an area of ongoing investigation. Effects in adolescents and in pregnancy are less well characterised, and current labelling advises against use during pregnancy.
Semaglutide is a synthetic peptide analogue of glucagon-like peptide-1, a gut hormone released after nutrient intake. The molecule contains 31 amino acid residues and differs from the native sequence at several positions. A non-natural residue at position eight resists the enzyme that normally truncates the hormone, while a lysine-linked fatty diacid side chain promotes binding to serum albumin. These two modifications extend the circulating half-life from minutes to roughly one week. The peptide is produced by solid-phase synthesis followed by selective acylation, and its identity and purity are confirmed by spectrometric and chromatographic techniques.
The primary target is the GLP-1 receptor, a class B G protein-coupled receptor expressed on pancreatic beta cells, in the gut, and in several brain regions. Receptor activation raises intracellular cyclic AMP, which potentiates glucose-dependent insulin secretion and lowers glucagon release when blood glucose is elevated. Signalling in the hypothalamus and brainstem is associated with reduced appetite and slower gastric emptying. Because the insulinotropic effect depends on prevailing glucose levels, the hypoglycaemic risk of the peptide alone is described as low in most study settings. The relative contribution of peripheral and central actions remains an active research question.
Two principal therapeutic variants exist under separate regulatory filings, one indicated for glycemic control in type 2 diabetes and one for chronic weight management. Both use the same active molecule; differences lie in formulation strength, titration schedule, and labeling. Regulatory agencies in the United States and European Union approved injectable forms in 2017 and 2018 respectively. An oral tablet formulation received approval later, using a carrier molecule to enhance absorption across the gastric epithelium. Labeling differs by jurisdiction and by indication.
The distinction between established facts and open questions matters here. That the peptide binds the GLP-1 receptor and stimulates insulin release in a glucose-dependent manner is well documented. How individual variability in receptor density, gastric emptying rate, and gut microbiome composition shapes response remains an active research area. Long-term outcomes beyond five years of continuous use are not yet fully characterized in published trials, and several extension studies are ongoing.
Semaglutide is a synthetic peptide analog of glucagon-like peptide-1, a hormone released from intestinal L cells after food intake. The molecule is a 31-amino-acid backbone modified at three positions to resist cleavage by dipeptidyl peptidase-4, the enzyme that degrades native GLP-1 within minutes. A lysine residue at position 26 carries a linker and a C18 fatty diacid, which promotes binding to serum albumin and slows renal clearance. These changes extend the circulating half-life from roughly two minutes to about one week in humans.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 or 280 nanometres is widely used to assess purity and to resolve related impurities. Liquid chromatography coupled to mass spectrometry confirms identity through the protonated molecular ion and fragment ions formed in tandem experiments. Capillary electrophoresis and peptide mapping after enzymatic digestion supply complementary information on charge variants and modification sites. Circular dichroism and nuclear magnetic resonance can report on secondary structure in solution. Absolute quantification usually depends on an external standard, and reported purity depends on the detection wavelength and integration parameters chosen.
Lyophilised material appears as a white to off-white cake or powder that is hygroscopic, and containers are usually equilibrated to room temperature before opening to limit condensation. Dissolution is performed in water, phosphate-buffered saline, or a mildly alkaline buffer, since solubility rises above neutral pH. Gentle inversion or low-speed mixing is preferred, because vigorous vortexing can promote surface denaturation and aggregation. Complete dissolution may require several minutes, and brief sonication is sometimes applied. Passing the solution through a 0.22 micrometre membrane removes particulates but does not by itself sterilise the liquid.
== See also == International relations since 1989 Iran–Saudi Arabia proxy conflict Iran–Israel proxy conflict Artificial intelligence arms race Arms race Nuclear arms race Digital Revolution Postmodernism Cold peace Interwar period Road to Now Ongoing armed conflicts
Heavy water reactors and some graphite moderated reactors can use natural uranium, but light water reactors must use low enriched uranium because of the higher neutron absorption of light water. Uranium enrichment removes some of the uranium-238 and increases the proportion of uranium-235. Highly enriched uranium (HEU), which contains an even greater proportion of uranium-235, is sometimes used in the reactors of nuclear submarines, research reactors and nuclear weapons.
=== Effects on identity === Human enhancement technologies can impact human identity by affecting one's self-conception. The argument does not necessarily come from the idea of improving the individual but rather changing who they are and becoming someone new. Altering an individual identity affects their personal story, development and mental capabilities. The basis of this argument comes from two main points: the charge of inauthenticity and the charge of violating an individual's core characteristics. Gene therapy has the ability to alter one's mental capacity, and through this argument, has the ability to affect their narrative identity. An individual's core characteristics may include internal psychological style, personality, general intelligence, necessity to sleep, normal aging, gender and being Homo sapiens. Technologies threaten to alter the self fundamentally to the point where the result is, essentially, a different person entirely. For example, extreme changes in personality may affect the individual's relationships because others can no longer relate to the new person. The capability approach focuses on a normative framework that can be applied to how human enhancement technologies affects human capabilities. The ethics of this does not necessarily focus on the make up of the individual but rather what it allows individuals to do in today's society.
=== Psychological and behavioral === Psychological and behavioral therapies are used across all forms of addiction, both alone and together with medication; commonly used approaches include CBT, motivational interviewing, contingency management (which provides tangible rewards for verified abstinence), and twelve-step facilitation. For stimulant use disorder, contingency management (particularly when combined with a community reinforcement approach) has the strongest supporting evidence among psychosocial treatments. For alcohol use disorder, structured twelve-step facilitation programs that encourage participation in Alcoholics Anonymous are at least as effective as other established therapies such as CBT for sustaining abstinence and may lower health-care costs. The creative arts therapies, including art therapy, music therapy, drama and dance, are sometimes offered alongside conventional treatment, and artwork produced during treatment has been used informally to aid assessment and track progress. A 2018 systematic review found insufficient evidence that visual art, drama, or dance and movement therapies reduce substance misuse, though music therapy showed some promise in preparing people to engage with treatment. Proposed benefits include providing a non-verbal outlet for difficult emotions and strengthening engagement in treatment.
== Co-discovery of insulin == Best moved in 1915 to Toronto, Ontario, where he started studying towards a bachelor of arts degree at University College, University of Toronto. In 1918, he enlisted in the Canadian Army serving with the 2nd Canadian Tank Battalion. After the war, he completed his degree in physiology and biochemistry. As a 22-year-old medical student at the University of Toronto he worked as an assistant to the surgeon Dr. Frederick Banting and contributed to the discovery of the pancreatic hormone insulin, which led to an effective treatment for diabetes. In the spring of 1921, Banting travelled to Toronto to visit John Macleod, professor of physiology at the University of Toronto, and asked Macleod if he could use his laboratory to isolate pancreatic extracts from dogs. Macleod was initially sceptical, but eventually agreed before leaving on holiday for the summer. Before leaving for Scotland he supplied Banting with ten dogs for experiment and two medical students, Charles Best and Edward Clark Noble, as lab assistants. It was reported that Best and Noble flipped a coin to see who would assist Banting during the first period of four weeks. According to Best, however, this was the product of a journalist’s imagination, or "newspaper fiction". Nonetheless, Frederick Banting is known to have mentioned this story when discussing the discovery of insulin.
Sources: en.wikipedia.org
Between 3.5 and 5 million people associate themselves with the Cossack cultural identity across the world, even though the majority have little to no connection to the original Cossack people because cultural ideals and legacy changed greatly with time. Cossack organizations operate in Russia, Ukraine, Belarus, Kazakhstan, Canada, and the United States.
=== Systemicity and translocation === Insecticides may be systemic or non-systemic (contact insecticides). Systemic insecticides penetrate into the plant and move (translocate) inside the plant. Translocation may be upward in the xylem, or downward in the phloem or both. Systemicity is a prerequisite for the pesticide to be used as a seed-treatment. Contact insecticides (non-systemic insecticides) remain on the leaf surface and act through direct contact with the insect. Insects feed from various compartments in the plant. Most of the major pests are either chewing insects or sucking insects. Chewing insects, such as caterpillars, eat whole pieces of leaf. Sucking insects use feeding tubes to feed from phloem (e.g. aphids, leafhoppers, scales and whiteflies), or to suck cell contents (e.g. thrips and mites). An insecticide is more effective if it is in the compartment the insect feeds from. The physicochemical properties of the insecticide determine how it is distributed throughout the plant.
In Bangladesh, a member of parliament is an individual who serves in the unicameral Jatiya Sangsad or House of the Nation. Members of the Jatiya Sangsad are elected at a general election, usually held once every five years unless Parliament is dissolved sooner by the president on the advice of the prime minister. Under the Constitution of Bangladesh, an individual is required to be a citizen of Bangladesh and must have attained the age of 25 years in order to qualify for election to Parliament. The Parliament consists of 300 directly elected members from general seats elected by use of first past the post who represent single-constituencies, while 50 seats are reserved exclusively for women and are allocated on a proportional basis. After an election, the Election Commission allocates reserved seats to parties based on the number of general seats they won. A party then presents a list of candidates, each requiring a presenter and a seconder. If the number of candidates presented and seats allocated is equal, then there is no election and the reserved seats are filled in accordance with the candidate lists prepared by parties. In the event there are more candidates than seat allocations, the 300 MPs elected from general seats vote through use of the single transferable vote system to determine the reserved seats. In reality, there has never been an election for reserved seats as parties have never nominated more candidates than they have been allocated. In order to form a Government, a political party or alliance usually requires a simple majority in Parliament.
The company was founded by Herbert Hyman (1931–2014) in September 1963, as a coffee service for offices. His wife Mona (whom he married in 1966) and he honeymooned in Sweden where they discovered quality coffee. This sparked the decision to import, roast and sell gourmet coffee in Los Angeles, opening the first Coffee Bean store in 1968 in the Los Angeles neighborhood of Brentwood. Innovations included selling whole beans and touting their country of origin and allowing customers to observe the beans being roasted and then to sample varieties before making a purchase. By the 1970s the firm had expanded to 10 stores in Southern California and had added exotic teas to the menu. In the summer of 1987 an employee brought a blender to a Westwood store where he mixed together ice, coffee extract and chocolate powder, paving the way for the company's signature Ice Blended drinks. With the invention of the Ice Blended, the chain saw a surge in popularity. The drink was a predecessor to the Starbucks Frappuccino. In 1991, when it was first planning to expand into Los Angeles, Starbucks tried to purchase the firm, but Hyman turned them down. The opening of Starbucks stores in Los Angeles unexpectedly helped Coffee Bean's business, by driving curious customers to the area. In 1996, the Hymans sold the Asian franchise rights to Singaporean brothers Victor Sassoon and Sunny Sassoon. The Sassoons quickly expanded the company in the US and internationally, opening the first outlet in Singapore in 1996, and in Malaysia the following year.
Tolperisone (trade name Mydocalm among others) is a centrally acting skeletal muscle relaxant used for the treatment of increased muscle tone associated with neurological diseases. It has been used since the 1960s.
Sources: en.wikipedia.org
Native GLP-1 is a short-lived peptide cleared within one to two minutes by dipeptidyl peptidase-4 and related enzymes. Semaglutide keeps the receptor-binding backbone but adds substitutions and a lipid chain. These changes block the main cleavage site and allow reversible albumin binding, extending the half-life to roughly 165 hours.
Albumin is the most abundant protein in plasma and carries molecules that bear fatty-acid chains. Binding shields the peptide from renal filtration and from peptidases, keeping a circulating reservoir. Slow release from this reservoir produces sustained receptor occupancy and supports infrequent dosing.
The insulinotropic effect is glucose-dependent, meaning secretion increases mainly when glucose is elevated. This property is often described as lowering the chance of hypoglycaemia when the compound is used alone. Other glucose-lowering agents used at the same time can still cause low blood glucose.
It is a glucagon-like peptide-1 receptor agonist, often grouped with the incretin mimetics. Its backbone is modified from the human hormone to resist enzymatic degradation and to bind albumin. These two features distinguish it from the native peptide.