The short version of GLP-1 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-09-04 and is reviewed periodically as new material appears.
Native GLP-1 is degraded rapidly by dipeptidyl peptidase-4. Semaglutide resists this cleavage because alanine at position 8 is replaced by alpha-aminoisobutyric acid. A second substitution at position 34 introduces arginine, which further stabilizes the peptide. The most distinctive modification is a spacer and C18 fatty diacid attached at lysine 26, enabling strong albumin affinity. These three changes together produce a half-life measured in days rather than minutes, and the same structural logic underlies other long-acting analogs in this class.
Semaglutide is a synthetic peptide analog of glucagon-like peptide-1, a hormone released from intestinal L-cells after food intake. It contains 31 amino acids and differs from native GLP-1 through modifications that slow enzymatic breakdown. The peptide was developed to extend the short circulating half-life of endogenous GLP-1, which is measured in minutes. Researchers introduced the compound in the early 2010s. Two backbone changes and a fatty acid side chain define its structure, distinguishing it from earlier GLP-1 receptor agonists.
The compound binds the GLP-1 receptor on pancreatic beta cells and other tissues, activating a G-protein signaling cascade that raises intracellular cyclic AMP. This action increases glucose-dependent insulin secretion when blood glucose is elevated, while binding also slows gastric emptying and reduces glucagon release. In the central nervous system, receptor activation in the hypothalamus and brainstem contributes to reduced appetite. The fatty acid chain binds albumin, which protects the peptide from renal filtration and enzymatic degradation. This albumin binding is central to its extended circulation time.
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.
Serum protein binding dominates the pharmacokinetic profile. The attached chain associates strongly with albumin, shielding the peptide from enzymatic attack and slowing filtration by the kidney. This interaction extends the circulation half-life to roughly one week in humans, which supports weekly administration intervals. An oral version pairs the peptide with an absorption enhancer that transiently alters gastric epithelium, permitting limited uptake; bioavailability by that route is substantially lower than by injection.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | 31 amino acids |
| Backbone modification | Aib at position 8 | Blocks DPP-4 cleavage |
| Fatty acid chain | C18 diacid | Supports albumin binding |
| Native half-life | 1 to 2 minutes | Endogenous GLP-1 |
| Analog half-life | Approximately one week | Extended by albumin binding |
Stability studies focus on deamidation of asparagine and glutamine residues, oxidation of methionine, and aggregation into higher-order species. The fatty acid side chain adds susceptibility to oxidative change and can promote self-association at high concentration. Lyophilised material is comparatively robust when kept cold and dry, while aqueous solutions require refrigeration and protection from light. Forced degradation experiments under heat, acid, base, and peroxide conditions establish the specificity of each analytical method. Which degradation route dominates under real storage conditions depends on the formulation and stays formulation-specific.
Handling guidance for research quantities calls for single-use aliquots, an inert atmosphere where practical, and avoidance of repeated freeze-thaw cycles that accelerate aggregation. Certificates of analysis typically report purity by peak area, water content, counter-ion identity, and residual solvent levels. In the scientific literature the compound is usually described by its full amino acid sequence, its registry number, or its structural class rather than by any proprietary label. Reporting standards vary between journals, and reviewers increasingly request raw chromatograms alongside tabulated purity figures. Whether current purity thresholds are adequate for every experimental context is debated.
Reversed-phase high-performance liquid chromatography with ultraviolet detection is the dominant approach for peptide purity assessment, usually paired with mass spectrometry to confirm molecular mass and sequence. Peptide mapping by enzymatic digestion and tandem mass spectrometry locates modifications such as deamidation and oxidation. Quantitation in plasma matrices can be performed by LC-MS/MS after solid-phase extraction. Method validation follows general guidance on accuracy, precision, linearity, and limits of detection. Comparability of results between laboratories, when no shared reference standard is available, remains an open question.
Lyophilized semaglutide powder is typically held at minus twenty degrees Celsius for long-term storage. At that temperature, solid-state degradation reactions proceed slowly and the peptide remains intact for extended periods. Repeated freeze-thaw cycles are best avoided because they promote aggregation and can shift the proportion of monomeric peptide present. Working aliquots are often prepared so that each portion is thawed only once, and desiccant is placed inside the vial to limit moisture uptake.
Identity and purity are usually assessed by reverse-phase high-performance liquid chromatography coupled to mass spectrometry. Retention time and observed mass are compared against a reference standard run under identical conditions. Impurity profiles reveal deamidation products, oxidized methionine variants, and truncated fragments that arise during synthesis or storage. Peptide mapping through enzymatic digestion confirms the primary sequence, while amino acid analysis offers an independent check on overall composition.
This assumption arose from the dopamine hypothesis that maintains that both schizophrenia and bipolar disorder are a result of excessive dopamine activity. Furthermore, psychomotor stimulants like cocaine that increase dopamine levels can cause psychotic symptoms if taken in excess. Chlorpromazine and other typical antipsychotics are primarily blockers of D2 receptors. An almost perfect correlation exists between the therapeutic dose of a typical antipsychotic and the drug's affinity for the D2 receptor. Therefore, a larger dose is required if the drug's affinity for the D2 receptor is relatively weak. A correlation exists between average clinical potency and affinity of the antipsychotics for dopamine receptors. Chlorpromazine tends to have a greater effect at serotonin receptors than at D2 receptors, which is notably the opposite effect of the other typical antipsychotics. Therefore, chlorpromazine's effects on dopamine and serotonin receptors are more similar to the atypical antipsychotics than to the typical antipsychotics. Chlorpromazine and other antipsychotics with sedative properties such as promazine and thioridazine are among the most potent agents at α-adrenergic receptors. Furthermore, they are also among the most potent antipsychotics at histamine H1 receptors. This finding is in agreement with the pharmaceutical development of chlorpromazine and other antipsychotics as anti-histamine agents.
10 August – 2022 monkeypox outbreak: Evidence of human-to-dog transmission is reported.On 4 August, a preprint reports that early post-exposure ring vaccination despite high efficacy "did not completely prevent breakthrough infections".On 15 August, a preprint suggests the virus has potential to infect a diverse range of native animals across Europe.On 16 August, a review recommends a 'living guideline' framework for needed clinical management research.On 19 August, a CDC study summarizes current knowledge about the transmission of monkeypox.Wastewater surveillance, which substantially expanded during the COVID-19 pandemic is used to detect monkeypox, with one team of researchers describing their qualitative detection method on 31 August.
Therefore, the development of devices facilitating the transition from samples at higher pressure and in condensed phase (solid or liquid) into a vacuum system has been essential to develop MS as a potent tool for identification and quantification of organic compounds like peptides. MS is now in very common use in analytical laboratories that study physical, chemical, or biological properties of a great variety of compounds. Among the many different kinds of mass analyzers, the ones that find application in LC–MS systems are the quadrupole, time-of-flight (TOF), ion traps, and hybrid quadrupole-TOF (QTOF) analyzers.
=== RluA === The RluA domain of these proteins can identify the substrate through a different protein binding to the substrate and then particular bonds to the RluA domain. PUS 5 is not well studied and located pseudouridine synthase and similar to Pus 2 does not have a mitochondrial signal targeting sequence. The protein modifies U2819 of mitochondrial 21S rRNA. Also suspected that Pus 5 modifies some uridines in the mRNA, but again more data is needed to confirm. PUS 6 has one that only modifies U31 of cytoplasmic and mitochondrial tRNA. Pus 6 is also known to modify mRNA. PUS 8 also known as Rib2/Pus8p modifies cytoplasmic tRNA at position U32. On the C-terminus there is a DRAP-deaminase domain related to the biosynthesis of riboflavin. The RluA and DRAP or deaminase domain related to riboflavin synthase have completely separate functions in the protein and it is not known whether they interact with each other. PUS 8 is necessary in yeast, but that is suspected to be related to the riboflavin synthesis and not the pseudouridine modification. PUS 9 and PUS 8 catalyze the same position in mitochondrial tRNA instead of cytoplasmic. It is the only PUS protein that contains a mitochondrial targeting signal domain on the N-terminus. Studies suggest that PUS 9 can modify mRNAs, which would mean less substrate specificity.
=== Hematopoietic stem cell transplant === Bronchiolitis obliterans affects up to 5.5% of people who have received HSCT. One of the biggest risk factors after HSCT is the development of GVHD with a 14% risk. Other risk factors post transplant including tobacco use, age of donor, age of recipient, lower baseline FEV1/FVC ratio, non-caucasian race, peripheral and lower circulating IgG levels. Studies have, however, shown mixed results regarding these other risk factors. There has been an association shown between the increased use of peripheral stem cells and the risk of developing bronchiolitis obliterans. Also, research has shown an increased risk for developing the disease within the first year of transplant if the person is infected with respiratory syncytial virus or parainfluenza virus within the first 100 days post transplant.
Sources: en.wikipedia.org
=== Br === Roscoe Brady (1923–2016). American biochemist at the National Institute of Neurological Disorders and Stroke, who identified many enzyme defects responsible for metabolic diseases. Member Natl. Acad. Sci. USA. Herman Branson (1914–1995). American physicist and biochemist who participated at Caltech in the discovery of the α-helix Sydney Brenner (1927–2019). South African biochemist at Cambridge, and later Berkeley, known for work on the genetic code and more recently for establishing Caenorhabditis elegans as a model organism. Nobel prize in Physiology or Medicine (2002) Roger Brent (b. 1955). American molecular biologist at the University of Washington known for work on gene regulation and systems biology Kenneth Breslauer (b. 1947). American biochemist at Rutgers University (born in Sweden of German parents), who has studied DNA damage and repair, including why certain mutations escape repair and result in cancer. Bernard Brodie (1907–1989). American biochemist and pharmacologist at the National Heart Institute, regarded as the founder of modern pharmacology. He studied drug metabolism and the mechanisms of drug effects. Member Natl. Acad. Sci. USA. Adrian John Brown FRS (1852–1920). British expert on brewing and malting at the University of Birmingham. He was a pioneer of enzyme kinetics and proposed an explanation of enzyme saturation. Patrick O. Brown (b. 1954). American biochemist at Stanford.
Sydney Harbour A unit of volume used in Australia for water. One Sydney Harbour is the amount of water in Sydney Harbour: approximately 562 gigalitres (562,000,000 cubic metres, or 0.562 cubic kilometres); or in terms of the more unusual measures above, about 357 Melbourne Cricket Grounds, 238,000 Olympic Swimming pools, or 476,000 acre-feet. The Grand Canyon With a volume measure approximately 4 orders of magnitude greater than Sydney Harbour, the volume of the Grand Canyon may be used to visualize even larger things, like the magma chamber underneath Yellowstone and other things. According to the National Park Service, the volume of the Grand Canyon is 4.17 trillion cubic metres (5.45 trillion cubic yards) which is 4,170 km3 (1,000 mi3).
== Signs and symptoms == Muscle dysfunction and weakness – This occurs in major muscles, but also may manifest as: diplopia, low cardiac output, dysphagia, and respiratory depression due to respiratory muscle weakness. Mental status changes – This may range from irritability to gross confusion, delirium, and coma. White blood cell dysfunction, causing worsening of infections. Instability of cell membranes due to low adenosine triphosphate (ATP) levels – This may cause rhabdomyolysis with increased serum levels of creatine phosphokinase, and also hemolytic anemia. Increased affinity for oxygen in the blood caused by decreased production of 2,3-bisphosphoglyceric acid. If hypophosphatemia is chronic; rickets in children or osteomalacia in adults may develop.
On August 23, 1879, 26 members of the Christian Scientists' Association were granted a charter to form the Church of Christ (Scientist). Services were held in people's homes in Lynn and later in Hawthorne Hall, Boston. On January 31, 1881, Eddy was granted a charter to form the Massachusetts Metaphysical College to teach "pathology, ontology, therapeutics, moral science, metaphysics, and their application to the treatment of disease." The college lived wherever Eddy did; a new sign appeared on 8 Broad Street. In October 1881 there was a revolt. Eight church members resigned, signing a document complaining of Eddy's "frequent ebullitions of temper, love of money, and the appearance of hypocrisy." Only a few students remained, including Calvin Frye, who became Eddy's most loyal personal assistant. They appointed Eddy pastor of the church in November 1881, and drew up a resolution in February 1882 that she was "the chosen messenger of God to the nations." Despite the support, the resignations ended Eddy's time in Lynn. The church was struggling and her reputation had been damaged by the disputes. By now 61 years old, she decided to move to Boston, and in early 1882 rented a house at 569 Columbus Avenue, a silver plaque announcing the arrival of the Massachusetts Metaphysical College.
Sources: en.wikipedia.org
Dorothy Anderson, Administrative Officer, Department of Social Security. John Elwyn Anderson. For services to the community, particularly Lifesaving, in South Wales. Royan Stuart Anderson, Constable, Operational Support Unit, British Transport Police. For services to Public Transport. Timothy John Anderson, Sergeant, Derbyshire Constabulary. For services to the Police. Edmund Robert Askey. For services to Tourism in Blackpool, Lancashire. Charles Keith Atkinson. For services to Young People in Nottinghamshire and to Rowing. Elizabeth Atkinson, Member, Northumberland County Council. For services to Local Government. Marjone Oxnard Atkinson. For services to the community on the Pennywell Estate, Sunderland, Tyne and Wear. Peggy Baerlein. For services to the Lister Hospital, Hertfordshire. Beryl Bailey, Support Grade Band 1, Home Office. Peter Edwin Bailey, lately Senior Doorkeeper, House of Lords. Albert John Baker. For services to War Pensions Committees in London. Elsie Evelyn Baker. For services to the Girls' Brigade on Guernsey. Kenneth Walter Ball, lately Honorary Secretary, British Transport Pensioners' Federation. For services to the Railway Industry. Jack Bonner Barlow. For services to Local Councils in the former South Glamorgan and to the community in Sully. Andrew Brown Barr. For services to the Royal Agricultural Benevolent Institution and to the Essex Agricultural Society. Dennis Gordon Bartholomew. For services to the community in Whiston, South Yorkshire. Haydn Sydney Bateman, Auxiliary Coastguard-in-charge, Her Majesty's Coastguard, St Govans, Dyfed.
Regardless of their mechanism, the menstrual disturbances associated with spironolactone can usually be controlled well by concomitant treatment with a birth-control pill, due to the progestin component.
=== 27 May === A spokeswoman for the German Defence Ministry confirmed that Ukraine had formally asked to be supplied with the Taurus KEPD 350 cruise missile. In Kharkiv Oblast, a woman was killed and another civilian was injured by Russian shelling in Kupiansk. Mikhail Vedernikov, Governor of Russia's Pskov Oblast, claimed that two drones struck an administrative building for a nearby oil pipeline, causing an explosion. No casualties were reported, however the building was damaged. The attack occurred less than ten kilometres from the Belarus border. In Kursk Oblast, a construction worker was reported to have been killed by Ukrainian shelling near the village of Plekhovo, a few kilometers from the international border. Another civilian, a security guard was killed by shelling in Shebekino, Belgorod Oblast. The Russian Defence Ministry claimed that its forces had intercepted two Storm Shadow missiles, 19 drones and several HIMARS and HARM missiles from Ukraine in the past 24 hours. The German Foreign Ministry confirmed that hundreds of its educational and cultural workers, including employees at the German school in Moscow and at the local branch of the Goethe Institute were to be expelled from Russia starting in June after it imposed a limit on the number of German employees in retaliation for the expulsion of Russian diplomats and staff from Germany.
Sources: en.wikipedia.org
It is a synthetic analog of GLP-1 produced through medicinal chemistry to resist enzymatic degradation. The design goal was longer circulation than the native hormone.
A fatty acid side chain attaches the peptide to serum albumin, which shields it from kidney filtration and protease activity. This interaction is the main reason its circulation time is extended.
No. The native hormone is GLP-1, and semaglutide is an engineered variant with three deliberate structural alterations. It does not appear in unmodified biological sources.
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.