The short version of GLP-1 analogue fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-08-29 and is reviewed periodically as new material appears.
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.
Quantification and purity assessment rely on separation methods coupled to optical or mass detection. Reversed-phase high-performance liquid chromatography resolves the intact peptide from related impurities and is the standard assay technique. Size-exclusion chromatography measures aggregates, while ion-exchange chromatography separates charge variants produced by deamidation. Mass spectrometry confirms identity and detects mass shifts of a few daltons. In biological matrices, liquid chromatography with tandem mass spectrometry is often used because immunoassays can cross-react with endogenous GLP-1 or with circulating fragments.
As a peptide, semaglutide is sensitive to conditions that break amide bonds or modify side chains. Deamidation of asparagine and glutamine residues, oxidation of methionine and tryptophan, and non-covalent aggregation are the main degradation routes described in published stability work. Rate depends strongly on pH, buffer species, ionic strength, temperature and exposure to light. Formulators therefore choose a defined solution pH and often add excipients such as phosphate buffer, propylene glycol and phenol, each of which plays a separate role in pH control, tonicity or preservation.
Storage guidance for the finished injectable product distinguishes the unused state from the in-use state. Before first use, pens are kept refrigerated between 2 and 8 degrees Celsius, protected from light, and never frozen, since freezing can disrupt the peptide or the device. After first use, label instructions in several markets permit storage at room temperature up to about 30 degrees Celsius for a limited number of days. Solid research-grade material is normally held at or below minus 20 degrees Celsius, often with desiccant, and allowed to equilibrate before opening.
| 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 |
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.
Storage at minus 20 degrees Celsius or lower in a desiccated container preserves the peptide for extended periods, while working solutions are commonly held at two to eight degrees Celsius for short intervals. Light exposure and repeated freeze-thaw cycles accelerate degradation, so dividing material into single-use aliquots is generally recommended. Adsorption to glass and plastic surfaces can lower the measured concentration of dilute solutions, particularly below one milligram per millilitre. The degradation routes most often reported for GLP-1 analogues are deamidation, methionine oxidation, and backbone hydrolysis. Relative rates under specific conditions are frequently described only for individual formulations.
容器与密封系统同样参与稳定性表现。硅油涂层、胶塞材质与顶空氧含量可能改变聚集速率与氧化水平。分析结果因此需要在完整包装形式下评估，而不能仅凭原料药数据推断。法规文件通常要求同时提交批次数据与代表性容器中的稳定性趋势。
关于降解产物的免疫原性风险，文献中仍有讨论空间。体外聚集水平与临床免疫反应之间的定量关系尚未确立。多数公开研究只报告理化指标，缺少长期随访的对应数据。这一问题在生物类似物比对中尤其受到关注。
市售注射用制剂通常要求在二至八摄氏度冷藏保存，并避免光照与冻结。部分多剂量笔在首次使用后允许在不超过三十摄氏度的环境中存放有限周数，具体期限由辅料与防腐剂体系决定。反复冻融会促进肽链聚集并改变可见颗粒计数，因此应予避免。冻干粉末在干燥、避光、低温条件下更为稳定。溶液配制后宜使用低吸附容器，以减少肽类在塑料或玻璃表面的损失。
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.
Immunology/Serology uses the process of antigen-antibody interaction as a diagnostic tool. Compatibility of transplanted organs may also be determined with these methods. Immunohematology, or blood bank determines blood groups, and performs compatibility testing on donor blood and recipients. It also prepares blood components, derivatives, and products for transfusion. This area determines a patient's blood type and Rh status, checks for antibodies to common antigens found on red blood cells, and cross matches units that are negative for the antigen. Urinalysis tests urine for many analytes, including microscopically. If more precise quantification of urine chemicals is required, the specimen is processed in the clinical biochemistry lab. Histopathology processes solid tissue removed from the body (biopsies) for evaluation at the microscopic level. Cytopathology examines smears of cells from all over the body (such as from the cervix) for evidence of inflammation, cancer, and other conditions. Molecular diagnostics includes specialized tests involving DNA and RNA analysis. Cytogenetics involves using blood and other cells to produce a DNA karyotype. This can be helpful in cases of prenatal diagnosis (e.g. Down's syndrome) as well as in some cancers which can be identified by the presence of abnormal chromosomes. Surgical pathology examines organs, limbs, tumors, fetuses, and other tissues biopsied in surgery such as breast mastectomies.
== Veterinary use == Buprenorphine is commonly used as a long-lasting post-operative analgesic in small animal veterinary practice. Buprenorphine can be administered via subcutaneous, transdermal, intravenous, or intramuscular routes. Buprenorphine provides analgesia for 6–8 hours in dogs and 4–8 hours in cats when administered as an intramuscular or intravenous injection. Buprenorphine as a partial agonist of the mu-receptor has less adverse effects than full agonists. A transdermal application can provide analgesia for up to 4 days in cats. The oral-transmucosal route has been investigated due to the potential for client administration but variability in bio-availability and other issues limit this usage. When used in combination with local anaesthetics or a non-steroidal anti-inflammatory drug buprenorphine provides good analgesia for ovariohysterectomies and orchidectomies. In horses buprenorphine can be used for castration and dental extraction; however, buprenorphine is not commonly used in horses as a post-operative analgesic due to potential for adverse gastrointestinal effects and locomotive stimulation. Buprenorphine is commonly given alongside acepromazine or a2 adrenergic receptor agonists
=== LS-SCLC === In cases of LS-SCLC, combination chemotherapy is administered together with concurrent chest radiotherapy. Chest radiotherapy has been shown to improve survival in LS-SCLC. Because SCLC usually metastasizes widely very early on in the natural history of the tumor, and because nearly all cases respond dramatically to chemotherapy and/or radiotherapy, there has been little role for surgery in this disease since the 1970s. However, in cases of small, asymptomatic, node-negative SCLC's ("very limited stage"), surgical excision may improve survival when used prior to chemotherapy.
Arsenic biochemistry is the set of biochemical processes that can use arsenic or its compounds, such as arsenate. Arsenic is a moderately abundant element in Earth's crust, and although many arsenic compounds are often considered highly toxic to most life, a wide variety of organoarsenic compounds are produced biologically and various organic and inorganic arsenic compounds are metabolized by numerous organisms. This pattern is general for other related elements, including selenium, which can exhibit both beneficial and deleterious effects. Arsenic biochemistry has become topical since many toxic arsenic compounds are found in some aquifers, potentially affecting many millions of people via biochemical processes.
Operation Protea had exposed a glaring lack of professionalism on the part of FAPLA units, which had relied too heavily on their Soviet advisers and were almost immediately routed once they had to leave their fortified bases. In terms of training, morale, organisation, and professional competence—including the ability to operate its own equipment with effectiveness—the Angolan army had proved decidedly vulnerable. Protea indicated that it was in no condition to repel or even inflict serious losses on the South African expeditionary troops, resulting in a ratio of casualties almost overwhelmingly in the SADF's favour. That debacle led to a greater FAPLA dependency on augmented Cuban forces and another large arms deal, valued in excess of one billion dollars, being signed with the Soviet Union. Defence expenditures increased to consume 50% of Angola's state budget by the end of 1982. FAPLA embarked on a massive recruiting drive, purchased new T-54/55 and T-62 tanks from the Soviet Union, and took delivery of about thirty new combat aircraft, including twelve Sukhoi Su-20 strike fighters. It also ordered more air search radars and surface-to-air missiles to replace those destroyed in Protea. While Namibianisation altered the tactical realities of the war on the Cutline, the SADF was planning a fourth operation modelled after Sceptic, Protea, and Daisy. In April 1982, PLAN insurgents killed 9 South African soldiers near Tsumeb, over 200 kilometres south of the border.
Sources: en.wikipedia.org
monomer A molecule or compound which can exist individually or serve as a building block or subunit of a larger macromolecular aggregate known as a polymer. Polymers form when multiple monomers of the same or similar molecular species are connected to each other by chemical bonds, either in a linear chain or a non-linear conglomeration. Examples include the individual nucleotides which form nucleic acid polymers, the individual amino acids which form polypeptides, and the individual proteins which form protein complexes.
While in his early teens, Tolkien had his first encounter with a constructed language, Animalic, an invention of his cousins, Mary and Marjorie Incledon. At that time, he was studying Latin and Anglo-Saxon. Their interest in Animalic soon died away, but Mary and others, including Tolkien himself, invented a new and more complex language called Nevbosh. The next constructed language he came to work with, Naffarin, would be his own creation. Tolkien learned Esperanto some time before 1909. Around 10 June 1909 he composed "The Book of the Foxrook", a sixteen-page notebook, where the "earliest example of one of his invented alphabets" appears. Short texts in this notebook are written in Esperanto. In 1911, while they were at King Edward's School, Tolkien and three friends, Rob Gilson, Geoffrey Bache Smith, and Christopher Wiseman, formed a semi-secret society they called the T.C.B.S. The initials stood for Tea Club and Barrovian Society, alluding to their fondness for drinking tea in Barrow's Stores near the school and, secretly, in the school library. After leaving school, the members stayed in touch and, in December 1914, they held a council in London at Wiseman's home. For Tolkien, the result of this meeting was a strong dedication to writing poetry.
Myomesin is a protein family found in the M-line of the sarcomere structure. Myomesin has various forms throughout the body in striated muscles with specialized functions. This includes both slow and fast muscle fibers. Myomesin are made of 13 domains including a unique N-terminal followed by two immunoglobulin-like (Ig) domains, five fibronectin type III (Fn) domains, five more Ig domains. These domains all promote binding which indicates that myomesin is regulated through binding.
Smooth muscle is involuntary and non-striated. It is divided into two subgroups: the single-unit (unitary) and multiunit smooth muscle. Within single-unit cells, the whole bundle or sheet contracts as a syncytium (i.e. a multinucleate mass of cytoplasm that is not separated into cells). Multiunit smooth muscle tissues innervate individual cells; as such, they allow for fine control and gradual responses, much like motor unit recruitment in skeletal muscle. Smooth muscle is found within the walls of blood vessels (such smooth muscle specifically being termed vascular smooth muscle) such as in the tunica media layer of the large (aorta) and small arteries, arterioles and veins. Smooth muscle is also found in lymphatic vessels, the urinary bladder, uterus (termed uterine smooth muscle), male and female reproductive tracts, the gastrointestinal tract, the respiratory tract, the arrector pili of skin, the ciliary muscle, and the iris of the eye. The structure and function is basically the same in smooth muscle cells in different organs, but the inducing stimuli differ substantially, in order to perform individual actions in the body at individual times. In addition, the glomeruli of the kidneys contain smooth muscle-like cells called mesangial cells.
== Description == Lotus plants are adapted to grow in the flood plains of slow-moving rivers and delta areas. Stands of lotus drop hundreds of thousands of seeds every year to the bottom of the pond. Some sprout immediately, though most are eaten by wildlife. The remaining seeds can remain dormant for an extensive period of time as the pond silt fills in and dries out. During flood conditions, sediments containing these seeds are broken open, and the dormant seeds rehydrate and begin a new lotus colony. Lotus plants are cultivated in nutrient-rich, loamy, and often flooded soils, requiring warm temperatures and specific planting depths, with propagation via rhizomes, seeds, or tissue culture. It is harvested by hand or machine for stolons, flowers, seeds, and rhizomes over several months depending on climate and variety. It is the national flower of India and unofficially of Vietnam. It has large leaves and flowers that can regulate their temperature, produces long-living seeds, and contains bioactive alkaloids. Under favourable circumstances, the seeds of this aquatic perennial may remain viable for many years, with the oldest recorded lotus germination being from seeds 1,300 years old recovered from a dry lakebed in northeastern China. Therefore, the Chinese regard the plant as a symbol of longevity.
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.
Ice formation concentrates solutes and can mechanically stress the peptide or damage the delivery device. Thawing afterwards may leave aggregates that are not visible to the eye. Refrigeration keeps the solution above its freezing point while slowing chemical degradation.