This is a working overview of GLP-1 receptor agonist, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-01-25. Anything still debated is marked as such rather than presented as settled.
Degradation proceeds along several parallel routes. Deamidation of asparagine and glutamine residues generates charged variants that shift retention time in chromatographic analysis. Oxidation targets methionine and can be accelerated by trace metals or dissolved oxygen. Non-covalent aggregation produces dimers, oligomers, and larger species that are difficult to reverse. Isomerisation at aspartate residues is slower but measurable under thermal stress. The distribution among these pathways depends on pH, buffer composition, ionic strength, and the presence of excipients such as sugars or surfactants.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nm is the standard purity method, reported as area percent. Mass spectrometry, usually with electrospray ionisation, confirms identity and reveals covalent modifications. Size-exclusion chromatography quantifies aggregates and fragments. Peptide mapping after enzymatic digestion localises changes to specific sequence regions. Circular dichroism and infrared spectroscopy report on secondary structure, while light scattering tracks particle formation in liquid formulations. No single technique captures every quality attribute.
Quality control relies on pharmacopoeial monographs where they exist, combined with in-house specifications for identity, purity, water content, and counter-ion composition. Reference standards allow calibration across laboratories, although certified materials for every analogue are not universally obtainable. Batch records, chromatograms, and mass spectra form the documentation trail. Regulatory classification varies by jurisdiction and intended use, and research-grade material differs from pharmaceutical-grade material in testing scope. Analytical uncertainty is often expressed as relative standard deviation across replicate injections.
Semaglutide 是一种经结构修饰的胰高血糖素样肽-1 类似物，其主链与内源性 GLP-1(7-36) 约有百分之九十四的序列一致性。第 8 位丙氨酸被 α-氨基异丁酸取代，使二肽基肽酶-4 无法识别原有切割位点。第 34 位赖氨酸换为精氨酸，进一步降低酶解速率。第 26 位赖氨酸经间隔基连接一条含十八个碳的二酸脂肪链，该侧链赋予分子与血浆白蛋白结合的能力。
该分子作为 GLP-1 受体的选择性激动剂发挥作用，受体属于 B 类 G 蛋白偶联受体家族，激活后经 Gs 通路提升细胞内环腺苷酸水平。在胰腺 β 细胞，信号促进葡萄糖依赖性的胰岛素释放，血糖偏低时该作用明显减弱。在胰岛 α 细胞，胰高血糖素分泌受到抑制。中枢神经系统与胃肠道同样存在受体表达，相应信号参与食欲调节以及胃排空速率的降低。
皮下注射后吸收相对缓慢，绝对生物利用度约为百分之八十九，血药浓度峰值通常出现在给药后一到三天。与白蛋白结合使清除减慢，终末半衰期约为一百六十五小时，接近一周。连续给药约四到五周后达到稳态暴露水平。表观分布容积约为每千克零点二五升，血浆蛋白结合率超过百分之九十九。代谢以蛋白水解切割和脂肪二酸侧链的 β-氧化为主，相关产物主要经尿液与粪便排出。
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white lyophilised powder | visual inspection of solid |
| Solubility | Freely soluble in water, pH dependent | buffer choice affects clarity |
| Typical storage | -20 °C, desiccated, protected from light | solution form kept at 2-8 °C |
| Primary purity method | RP-HPLC with UV detection, 214-220 nm | reported as area percent |
| Identity confirmation | LC-ESI-MS, approximately 4114 Da | compared with theoretical mass |
Development began in the early 2010s with the goal of extending GLP-1 activity beyond the brief window achieved by native peptide infusion. The earliest approved formulation was a subcutaneous injection given once weekly. A later oral tablet pairs the peptide with an absorption enhancer, sodium N-(8-[2-hydroxybenzoyl] amino) caprylate, usually shortened to SNAC. That carrier lowers local pH and helps the peptide cross gastric tissue. Both routes deliver the same active molecule.
Semaglutide is a synthetic peptide analog of human glucagon-like peptide-1, a gut hormone released after meals. Its backbone retains the GLP-1 sequence but incorporates two substitutions that slow enzymatic breakdown by dipeptidyl peptidase-4. A short polyethylene glycol linker and a C18 fatty diacid are attached to the peptide chain, allowing the molecule to bind serum albumin and remain in circulation far longer than the native hormone. The result is a circulating half-life measured in days rather than the minutes typical of endogenous GLP-1.
Receptor activation occurs at GLP-1 receptors distributed across pancreatic islets, the hypothalamus, and the gastrointestinal tract. Binding triggers G protein signaling that raises cyclic AMP and enhances glucose-dependent insulin release. Because the effect depends on prevailing glucose levels, insulin secretion does not rise when blood sugar is already low. Signaling in the brain and gut also influences appetite and gastric emptying, which is why the compound appears in both metabolic and weight-related research literature.
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.
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.
=== Economics === Following the US approval of Soliqua, Sanofi made a US$25 million milestone payment to Zealand. Zealand may receive additional payments up to US$110 million along with receiving royalties on global sales. Royalties paid to Zealand for Soliqua are based on a fixed low double-digit percentage of net sales. In January 2017, Sanofi announced that the wholesale acquisition cost (WAC) of a 3 ml pen of Soliqua is US$127. At the average dose used in clinical trials, this amounts to US$19.90 per day. According to Sanofi's Half-Year Financial Report, the net sales of Soliqua reached €9 million in the first six months of availability in the United States.
== Computational prediction of chiral properties == The prediction of chiral properties using computational methods has emerged as an important area in modern stereochemistry, complementing experimental techniques for characterizing and separating enantiomers. These approaches leverage machine learning algorithms and molecular representations to predict various chiral-specific behaviors, including chromatographic retention, optical rotation, and stereochemical assignments.
Phosphorus is used in trace amounts as a dopant for n-type semiconductors. The commercial use of gallium compounds is dominated by semiconductor applications – in integrated circuits, cell phones, laser diodes, light-emitting diodes, photodetectors, and solar cells. Selenium is used in the production of solar cells and in high-energy surge protectors. Boron, silicon, germanium, antimony, and tellurium, as well as heavier metals and metalloids such as Sm, Hg, Tl, Pb, Bi, and Se, can be found in topological insulators. These are alloys or compounds which, at ultracold temperatures or room temperature (depending on their composition), are metallic conductors on their surfaces but insulators through their interiors. Cadmium arsenide Cd3As2, at about 1 K, is a Dirac-semimetal – a bulk electronic analogue of graphene – in which electrons travel effectively as massless particles. These two classes of material are thought to have potential quantum computing applications.
IGF1 is a primary mediator of the effects of growth hormone (GH). Growth hormone is made in the anterior pituitary gland, released into the bloodstream, and then stimulates the liver to produce IGF1. IGF1 then stimulates systemic body growth, and has growth-promoting effects on almost every cell in the body, especially skeletal muscle, cartilage, bone, liver, kidney, nerve, skin, hematopoietic, and lung cells. In addition to its insulin-like effects (insulin being the main anabolic hormone in the body), IGF1 can also regulate cellular DNA synthesis. IGF1 binds to at least two cell surface receptor tyrosine kinases: the IGF1 receptor (IGF1R), and the insulin receptor. Its primary action is mediated by binding to its specific receptor, IGF1R, which is present on the surface of several cell types in a multitude of tissues. Binding to the IGF1R initiates intracellular signaling. IGF1 is one of the most potent natural activators of the Akt signaling pathway, a stimulator of cell growth and proliferation, and a potent inhibitor of programmed cell death. The IGF1 receptor and insulin receptor are two closely related members of a transmembrane tetrameric tyrosine kinase receptor family. They control vital brain functions, such as survival, growth, energy metabolism, longevity, neuroprotection and neuroregeneration.
Sources: en.wikipedia.org
=== Suspension of campaign === Sanders announced that he was suspending his campaign on April 8, 2020. He stated that he would remain on the ballot in the remaining states and continue to accumulate delegates with the goal of influencing the Democratic Party's platform. On April 14, Sanders endorsed Biden. Biden responded, "I think that your endorsement means a great deal. It means a great deal to me. I think people are going to be surprised that we are apart on some issues but we're awfully close on a whole bunch of others. I'm going to need you—not just to win the campaign, but to govern."
== Use and effects == While 2C-EF was briefly mentioned by Alexander Shulgin in his book PiHKAL (Phenethylamines I Have Known and Loved), its properties and effects were not described. Subsequently, in his book The Shulgin Index, Volume One: Psychedelic Phenethylamines and Related Compounds, Shulgin listed 2C-EF's dose range as 6 to 12 mg orally and its duration as 12 hours. This information was cited via personal communication with M. Mueller in 2006.
=== Ethnicity and socioeconomic status === The rates of breastfeeding in the African-American community remain much lower than those of any other race, for a variety of proposed reasons. These include the legacy of wet nursing during slavery, higher rates of poor perinatal health, higher stress levels, less access to support, and less flexibility in the workplace. While for other races, as socio-economic status increases, rates of breastfeeding also go up, for the African-American community, breastfeeding rates remain consistently low regardless of socio-economic class. There are also racial disparities in access to maternity care practices that support breastfeeding. In the US, primarily African-American neighborhoods are more likely to have facilities (such as hospitals and female healthcare clinics) that do not support breastfeeding, contributing to the low rate of breastfeeding in the African-American community. Comparing facilities in primarily African American neighborhoods to ones in primarily European-American neighborhoods, the rates of practices that support or discourage breastfeeding were: limited use of supplements (13.1% compared with 25.8%) and rooming-in (27.7–39.4%) Low-income mothers are more likely to have unintended pregnancies. Mothers whose pregnancies are unintended are less likely to breastfeed. Especially the combination of powdered formula with unclean water can be very harmful to the health of babies. In the late 1970s, there was a boycott against Nestle due to the large number of baby deaths due to formula. Dr.
=== Parasitology === MALDI-TOF spectra have been used for the detection and identification of various parasites such as trypanosomatids, Leishmania and Plasmodium. In addition to these unicellular parasites, MALDI/TOF can be used for the identification of parasitic insects such as lice or cercariae, the free-swimming stage of trematodes.
Moore supports creating a "service year option" in schools, which would enable high school graduates to do a gap year "in exchange for job training, mentorship, and other support including compensatory tuition at a state college or university." On January 19, 2023, Moore signed an executive order creating the Maryland Department of Service and Civic Innovation, a cabinet-level agency responsible for establishing a service-year option for all high school graduates. In February, he introduced the SERVE Act to create the "service year option program", which would pay young people $15 per hour for at least 30 hours a week for work in service to the community. The SERVE Act was signed into law in April 2023, and the service year program launched with 280 participating students in October 2023. The program expanded to include 600 participating students in its second year.
Sources: en.wikipedia.org
UPMC Shadyside is a nationally ranked, 520-bed non-profit, tertiary, teaching hospital located in the Shadyside neighborhood of Pittsburgh, Pennsylvania. UPMC Shadyside is a part of the University of Pittsburgh Medical Center (UPMC), and grouped in with the flagship UPMC Presbyterian. The hospital is near UPMC's flagship campus which houses Presbyterian and Montefiore. As the hospital is a teaching hospital, it is affiliated with University of Pittsburgh School of Medicine. The hospital has an emergency room to handle emergencies, with a rooftop helipad to transport critical patients to and from the hospital. UPMC Shadyside houses the flagship campus of the UPMC Hillman Cancer Center, a nationally ranked cancer hospital. UPMC Shadyside is part of UPMC's flagship medical entity and is located in Pittsburgh's Shadyside neighborhood, with 520 beds and nearly 1,000 primary care physicians. Founded in as the Pittsburgh Homeopathic Hospital, it changed its name to that of the neighborhood of Shadyside on May 12, 1938. Shadyside agreed to be bought by UPMC on June 5, 1996. UPMC Shadyside is home to the Hillman Cancer Center, home of the University of Pittsburgh Cancer Institute.
=== Autumn 2007: Deaths across north Texas === The spread of the drug to the outlying suburbs of Dallas was confirmed in September by the return of toxicology reports from the July 13 death of an 18-year-old student from McKinney, located northeast of Dallas in Collin County, and from two July deaths in nearby Tarrant County, one involving a 17-year-old male and the other, a 26-year-old male. Additional suburban deaths in September — in Irving to the west and Rockwall to the east — were believed to be linked to cheese heroin, though police cautioned toxicology reports would not likely be complete until November. The Tarrant County medical examiner's office announced on September 24 that a review of deaths in Tarrant County (west) and Denton County (north) showed an additional 15 deaths between 2004 and 2007 that appeared to be linked to "cheese," and Collin and Rockwall counties had reported one death each. These new figures brought the total number of deaths associated with cheese heroin in northern Texas to 40, a figure that included many older adults along with those age 18 and under.
=== Other appearances === "TV Eye" with Wylde Ratttz, Velvet Goldmine: Music from the Original Motion Picture, 1999. "Elephant Love Medley" with Nicole Kidman, Moulin Rouge! Music from Baz Luhrmann's Film, 2001. "El Tango de Roxanne" with Jose Feliciano, Moulin Rouge! Music from Baz Luhrmann's Film, 2001. "Your Song" with Alessandro Safina, Moulin Rouge! Music from Baz Luhrmann's Film, 2001. "Here's To Love" with Renée Zellweger, Down With Love: Music from and Included in the Motion Picture, 2003. "The Sweetest Gift", Unexpected Dreams – Songs From the Stars, 2006. "Be Our Guest" with Emma Thompson, Ian McKellen, and Gugu Mbatha-Raw, Beauty and the Beast, 2017. "Days in the Sun" with Adam Mitchell, Stanley Tucci, Ian McKellen, Emma Thompson, Emma Watson, Audra McDonald, Clive Rowe, Beauty and the Beast, 2017. "Something There" with Emma Watson, Dan Stevens, Ian McKellen, Emma Thompson, Nathan Mack, Gugu Mbatha-Raw, Beauty and the Beast, 2017. "The Mob Song", with Luke Evans, Josh Gad, Emma Thompson, Ian McKellen, Stanley Tucci, Nathan Mack, & Gugu Mbatha-Raw, Beauty and the Beast, 2017. "Better Tomorrows", Pinocchio, 2022.
The pharmaceutical company Rexar reformulated their weight loss drug Obetrol following its mandatory withdrawal from the market in 1973, under the Kefauver Harris Amendment to the Federal Food, Drug, and Cosmetic Act due to the results of the Drug Efficacy Study Implementation (DESI) program (which indicated a lack of efficacy). The new formulation simply replaced the two methamphetamine components with dextroamphetamine and amphetamine components of the same weight (the other two original dextroamphetamine and amphetamine components were preserved), preserved the Obetrol branding, and despite it lacking FDA approval, it still made it onto the market and was marketed and sold by Rexar for many years. In 1994, Richwood Pharmaceuticals acquired Rexar and began promoting Obetrol as a treatment for ADHD (and later narcolepsy as well), now marketed under the brand name of Adderall, a contraction of the phrase "A.D.D. for All" intended to convey that "it was meant to be kind of an inclusive thing" for marketing purposes. The FDA cited the company for numerous significant CGMP violations related to Obetrol discovered during routine inspections following the acquisition (including issuing a formal warning letter for the violations), then later issued a second formal warning letter to Richwood Pharmaceuticals specifically due to violations of "the new drug and misbranding provisions of the FD&C Act".
Sources: en.wikipedia.org
Reverse-phase high-performance liquid chromatography with ultraviolet detection is the usual choice, with results reported as area percent. Complementary methods such as size-exclusion chromatography and mass spectrometry are needed because a single separation cannot resolve every impurity class. Purity figures are therefore method dependent and should always be read alongside the technique used.
Oxidation mainly affects methionine residues and is promoted by dissolved oxygen, trace transition metals, and prolonged exposure to light. Buffer choice and the presence of antioxidants in a formulation can alter the rate appreciably. Because the products differ in mass by only a few units, mass spectrometry is often required to detect them.
Published data on long-term ambient stability are limited, so the question remains open rather than settled. Short excursions during transport are common in practice, and many suppliers use insulated packaging with cold packs. Where stability data are absent, cold-chain handling with temperature logging is the safer approach.
差别集中在三处：第 8 位残基被非天然氨基酸取代，第 34 位换成精氨酸，第 26 位增加一条脂肪酸侧链。前两处改动降低酶解速率，侧链则通过白蛋白结合延长循环时间。综合结果是半衰期从约两分钟延长到约一周。