If you have been reading about GLP-1 类似物 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.
Updated 2026-03-09. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Certificate of analysis documents from suppliers typically report purity by chromatographic area, water content, and counter-ion identity. Independent verification is advisable because reported values can be generated under differing conditions. Impurity profiles matter for research use, where aggregates, deamidation products, and residual solvents may influence experimental results. Container, lot, and chain-of-custody records support traceability. Analytical results are method-dependent, so comparisons between laboratories require the same procedure and reference standards.
Lyophilized peptide material is typically stored at or below -20 °C, with -80 °C used for longer-term archives. Vials should remain sealed and desiccated because moisture promotes aggregation and hydrolysis. Repeated freeze-thaw cycles are avoided since they can alter peptide conformation and reduce recovery. Once reconstituted, solutions are generally kept at 2-8 °C and used within a defined window. Stability beyond those windows depends on buffer composition and concentration, and exact limits are product-specific rather than universal.
Identity and purity are assessed with reversed-phase high-performance liquid chromatography, which separates the peptide from related impurities by hydrophobicity. Mass spectrometry confirms molecular weight and detects truncation or modification products. Peptide mapping after enzymatic digestion verifies the amino acid sequence. Quantitation is often performed by LC-MS/MS or by immunoassay, and the two approaches can give different values because they measure different things. Method validation parameters such as accuracy, precision, and limit of quantitation are reported alongside results.
| 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 |
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.
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.
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.
序列层面的改动同时解决了两个问题，即酶解稳定性与肾脏清除速度。天然 GLP-1 在循环中的半衰期仅约两分钟，主要被二肽基肽酶-4 迅速灭活。酰化侧链与白蛋白的可逆结合形成循环储库，使分子缓慢释放并持续激活受体。这种设计思路后来被广泛用于同类长效肽的开发，属于该类药物化学改造的典型范式。
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。
=== Pharmacodynamics === Esmodafinil has about 3-fold lower affinity for the dopamine transporter (DAT) compared to armodafinil or modafinil (Ki = 780 nM, 2,500 nM, and 2,300 nM, respectively). It showed about 2-fold lower potency than armodafinil and about 1.5-fold higher potency than modafinil as a dopamine reuptake inhibitor (DRI) in vitro (IC50Tooltip half-maximal inhibitory concentration = 8,700 nM, 4,000 nM, and 13,000 nM, respectively). Both enantiomers of modafinil preferentially bind to the DAT in an inward facing conformation that is associated with atypical DRI profiles. Esmodafinil was about 1.4- to 1.5-fold more potent than modafinil or armodafinil in substituting for cocaine in rodents. Esmodafinil and armodafinil have been said to have approximately equipotent pharmacological effects but differing pharmacokinetics. Esmodafinil has been researched for the treatment of cocaine addiction. Like armodafinil, esmodafinil attenuates the effects of cocaine by occupying the dopamine transporter. While doing so, esmodafinil increases dopamine levels in the nucleus accumbens to a lesser extent than cocaine. However, the short elimination half-life of esmodafinil has been cited as reason to investigate armodafinil as a cocaine addiction treatment instead.
He then moved to the Hebei province in North China, where he became a target of public scorn for being a remnant of the "old society", a belief that would only take further hold in China during The Cultural Revolution. He lived there in poverty for a few years before eventually becoming a monk. He finally moved back to Beijing after an unspecified amount of time and spent the remaining years of his life there, ostensibly as a caretaker of the Guanghua temple. Even with the faltering influence of the Qing Dynasty, Sun was nevertheless able to gain enough influence in the royal household to be privy to many of the court’s intimate secrets, such as the opium addiction and out-of-wedlock pregnancy of the Qing empress Wanrong, as well as reports that the emperor showed more interest in a eunuch than his wife. His preserved genitals, referred to as "treasure" by eunuchs as a slang term as well as in a literal fashion given the practice of eunuchs being buried with them as "complete men", were discarded by his siblings during the Cultural Revolution due to fear of persecution, given its connotation to the "old society". The fact that he could not be buried with his preserved genitals as a "complete man" remained a major source of distress for Sun for the remainder of his life.
By comparison, smaller scale civil defense programs were instituted in the United States starting in the 1950s, where schools and other public buildings had basements stocked with non-perishable food supplies, canned water, first aid, and dosimeter and Geiger counter radiation-measuring devices. Many of the locations were given "fallout shelter" designation signs. CONELRAD radio information systems were adopted, whereby the commercial radio sector (later supplemented by the National Emergency Alarm Repeaters) would broadcast on two AM radio frequencies in the event of a Civil Defense (CD) emergency. These two frequencies, 640 and 1240 kHz, were marked with small CD triangles on the tuning dial of radios of the period, as can still be seen on 1950s-vintage radios on online auction sites and museums. A few backyard fallout shelters were built by private individuals. Henry Kissinger's view on tactical nuclear war in his controversial 1957 book Nuclear Weapons and Foreign Policy was that any nuclear weapon exploded in air burst mode that was below 500 kilotons in yield and thus averting serious fallout, may be more decisive and less costly in human lives than a protracted conventional war. A list of targets made by the United States was released sometime during December 2015 by the U.S. National Archives and Records Administration. The language used to describe targets is "designated ground zeros".
Myrophine (Myristylbenzylmorphine) is an opiate analogue that was developed in 1952. It is a derivative of morphine. Myrophine is substituted with a 3-benzyl group and a 6-myristyl chain. It is metabolised to form benzylmorphine and then further to morphine, and so is a long-acting prodrug for morphine, but with a slow onset of effects. It is weaker than morphine as an analgesic but longer-lasting in effects, and was thought to have more local anesthetic effect than morphine, though with a somewhat greater tendency to cause reactions like itching and rash. In addiction studies conducted in human subjects in the 1950s, myrophine did not substitute for morphine in withdrawal, did not produce notable morphine-like effects, and did not produce addiction or dependence regardless of dose or how it was administered. Consequently, it was thought to be useful in treating pain in addicts who were being detoxified from other opioid drugs. It is a Schedule I drug in the US, considered to have high potential for abuse and no medical applications, and is controlled under international drug conventions. Myrophine is almost invariably used as the hydrochloride (free base conversion ratio 0.94) and has a DEA Administrative Controlled Substance Control Number of 9308. Myrophine is a Class A controlled substance in the UK, and is on the UN's Yellow list.
It is 2.7 million times more radioactive than the same molar amount of natural uranium (mostly uranium-238), due to its proportionally shorter half-life. A sample of radium metal maintains itself at a higher temperature than its surroundings because of the radiation it emits. Natural radium (which is mostly 226Ra) emits mostly alpha particles, but other steps in its decay chain (the uranium or radium series) emit alpha or beta particles, and almost all particle emissions are accompanied by gamma rays. Experimental nuclear physics studies have shown that nuclei of several radium isotopes, such as 222Ra, 224Ra and 226Ra, have reflection-asymmetric ("pear-like") shapes. In particular, this experimental information on radium-224 has been obtained at ISOLDE using a technique called Coulomb excitation.
Sources: en.wikipedia.org
seconds). In vacuum technology, the residence time of gases on the surfaces of a vacuum chamber can determine the pressure due to outgassing. If the chamber can be heated, the above equation shows that the gases can be "baked out"; but if not, then surfaces with a low residence time are needed to achieve ultra-high vacuums.
Aerobic respiration requires oxygen (O2) in order to create ATP. Although carbohydrates, fats, and proteins are consumed as reactants, aerobic respiration is the preferred method of pyruvate production in glycolysis, and requires pyruvate be transported by the mitochondria in order to be oxidized by the citric acid cycle. The products of this process are carbon dioxide and water, and the energy transferred is used to make bonds between ADP and a third phosphate group to form ATP (adenosine triphosphate), by substrate-level phosphorylation, NADH and FADH2.
[HbH]+ + O2 ⇌ HbO2 + H+ as this shows that when hydrogen ion concentration increases the equilibrium is shifted to the left in accordance with Le Châtelier's principle. Hydrogen ion concentration can be increased by the presence of carbon dioxide, which behaves as a weak acid.
==== Sexual dysfunction ==== Erectile dysfunction can be a consequence of vitamin D deficiency. Mechanisms may include the regulation of vascular stiffness, the production of vasodilating nitric oxide, and the regulation of vessel permeability. However, the clinical trial literature does not yet contain sufficient evidence that supplementation treats the problem. Part of the complexity is that vitamin D deficiency is also linked to morbidities that are associated with erectile dysfunction, such as obesity, hypertension, diabetes mellitus, hypercholesterolemia, chronic kidney disease and hypogonadism. In women, vitamin D receptors are expressed in the superficial layers of the urogenital organs. There is an association between vitamin D deficiency and a decline in sexual functions, including sexual desire, orgasm, and satisfaction in women, with symptom severity correlated with vitamin D serum concentration. The clinical trial literature does not yet contain sufficient evidence that supplementation reverses these dysfunctions or improves other aspects of vaginal or urogenital health.
In 2018, the US Special Inspector General for Afghanistan Reconstruction called the counternarcotics operation to date "a total failure". As the US military presence neared an end in 2020, Afghanistan was producing an estimated 85% of the world's opium. Having spent some $9 billion in the 20-year anti-drug campaign, US forces left Afghanistan in 2021, and the Taliban returned to power.
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.
The lyophilized powder is dissolved in a suitable solvent, often sterile water or a buffered diluent, with gentle mixing rather than vigorous shaking. Foaming and shear should be avoided because they can promote aggregation. The resulting solution is then stored cold and protected from light.