If you have been reading about GLP-1 receptor agonist 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 2025-11-15. Numbers and descriptions here follow the published literature rather than marketing material.
Reported molecular weight is approximately 4113.6 daltons for the free base, and the peptide is supplied as a lyophilized powder or in buffered liquid form depending on the intended use. It is freely soluble in water when formulated with appropriate excipients, though the unconjugated peptide shows limited stability at neutral pH over long periods. Analytical characterization typically relies on reversed-phase high-performance liquid chromatography and mass spectrometry. Purity specifications for research-grade material commonly exceed ninety-five percent by area. Isotopic and impurity profiles differ between suppliers.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula (free base) | C187H291N45O59 | Approximate; salt and hydrate forms differ |
| Molecular weight | ~4113.6 Da | Varies with counterion and hydration |
| Appearance | White to off-white powder | Lyophilized research material |
| Solubility class | Freely soluble in water | As formulated; native peptide less stable near neutral pH |
| Typical storage | 2 to 8 degrees Celsius | Protect from light; avoid repeated freeze-thaw |
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.
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.
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。
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 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.
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.
Lyophilized semaglutide is typically stored at temperatures between minus 20 and minus 80 degrees Celsius for long-term preservation. Short-term storage at 2 to 8 degrees Celsius is common for working aliquots. Repeated freeze-thaw cycles can degrade the peptide and are usually avoided. The molecule is hygroscopic in its solid form, so containers should remain sealed with desiccant. Solutions are less stable than powders and are generally prepared fresh. Light exposure is limited because aromatic residues can undergo photo-oxidation.
Semaglutide dissolves readily in water and in aqueous buffers near neutral pH. Solubility decreases near the isoelectric point, where net charge is minimal. Common laboratory solvents include phosphate-buffered saline and dilute ammonium bicarbonate. Strongly acidic or basic conditions may accelerate hydrolysis. Working concentrations are usually prepared by diluting a concentrated stock. Vial surfaces can adsorb small amounts of peptide at low concentrations, so carrier proteins or low-binding tubes are sometimes used.
Reverse-phase high-performance liquid chromatography is the standard method for purity assessment, separating the peptide from truncated or oxidized variants. Mass spectrometry confirms molecular mass and detects modifications, while ultraviolet absorbance near 280 nanometers supports concentration measurement through tryptophan and tyrosine residues. Circular dichroism can indicate secondary structure, though the peptide is largely helical in solution, and ion-exchange chromatography resolves charge variants. Purity values above 95 percent are typical for research-grade material. Stability studies track degradation over time under defined conditions.
While South Africa is known to be one of the more LGBTQ-friendly nations in the southern parts of Africa, corrective rape is still reported in South Africa. Rape, including corrective rape, disproportionately affects Black women. In South Africa, women are often seen as having less sexual and economic power than men. One of the factors associated with this inequality is strict gender roles, which have led to one of the highest rates of violence against women in the world. The South African government conducted a survey in 2009 on sexual assault. One in four men admitted to engaging in sexual activity with a woman who did not consent and nearly half of those men admitted to raping more than once. It is also estimated that a woman is raped every 26 seconds in South Africa. Corrective rape is used as a punishment for people who are gay or do not fit traditional gender roles, where often they are verbally abused before the rape. The perpetrator may claim to be teaching the women a lesson on how to be a "real woman". Because women have less control over their economic situation, which creates economic vulnerability, they have less control over their own sexual activities. Poor Black women who live in townships are more likely to become victims of corrective violence, and gay women are more likely to be isolated with little support, which increases their chances of being targeted. The South African Constitution states that no person shall be discriminated against based on their gender, race, or sexual orientation.
polyclonal Describing cells, proteins, or molecules descended or derived from more than one clone (i.e. from more than one genome or genetic lineage) or made in response to more than one unique stimulus. Antibodies are often described as polyclonal if they have been produced or raised against multiple distinct antigens or multiple variants of the same antigen, such that they can recognize more than one unique epitope. Contrast monoclonal.
C6H5OH + Hg(O2CCH3)2 → C6H4(OH)–HgO2CCH3 + CH3CO2H C6H4(OH)–HgO2CCH3 + NaCl → C6H4(OH)–HgCl + NaO2CCH3 The first such reaction, including a mercuration of benzene itself, was first reported by Otto Dimroth in 1898.
== Clinical significance == In vascular smooth muscle cell (VSMC), ADAMTS7 mediates VSMC migration, which plays an essential role during the development of atherosclerosis and restenosis. This proatherogenic effect has been demonstrated to specifically require the catalytic protease activity of ADAMTS7, as mice expressing a catalytically inactive mutant of the enzyme (E373Q) are similarly protected against atherosclerosis. Adamts7 deficiency in both the Ldlr−/– and Apoe−/– hyperlipidemic mouse models markedly attenuates formation of atherosclerotic lesions; furthermore, wire-injury experiments in the Adamts7−/– mouse show reduced neointima formation. The association of ADAMTS7 with atherosclerosis suggests that inhibition of ADAMTS7 should be atheroprotective in humans. A negative correlation between the expression levels of specific miRNAs and ADAMTS7 is observed in normal tissues but not in disease tissues, implying an altered miRNA-target interaction in the disease state. Accordingly, expression profiles of these miRNAs and ADAMTS7 may be useful diagnostic tools to differentiate cancer and lichen planus from normal tissues. ADAMTS7 has also been identified as a putative oncogene and reported to be mutated exclusively in Asians, which may have implications for the prevention and treatment of hepatocellular carcinoma. In addition, ADAMTS7 plays a crucial role in the pathogenesis of arthritis. For example, the FGF2/p65/miR-105/Runx2/ADAMTS axis is reportedly involved in osteoarthritis (OA) pathogenesis.
Sources: en.wikipedia.org
Chromatin immunoprecipitation (ChIP) is a method used to determine the location of DNA binding sites on the genome for a particular protein of interest. This technique gives a picture of the protein–DNA interactions that occur inside the nucleus of living cells or tissues. The in vivo nature of this method is in contrast to other approaches traditionally employed to answer the same questions. The principle underpinning this assay is that DNA-binding proteins (including transcription factors and histones) in living cells can be cross-linked to the DNA that they are binding. By using an antibody that is specific to a putative DNA binding protein, one can immunoprecipitate the protein–DNA complex out of cellular lysates. The crosslinking is often accomplished by applying formaldehyde to the cells (or tissue), although it is sometimes advantageous to use a more defined and consistent crosslinker such as dimethyl 3,3′-dithiobispropionimidate-2 HCl (DTBP). Following crosslinking, the cells are lysed and the DNA is broken into pieces 0.2–1.0 kb in length by sonication. At this point the immunoprecipitation is performed resulting in the purification of protein–DNA complexes. The purified protein–DNA complexes are then heated to reverse the formaldehyde cross-linking of the protein and DNA complexes, allowing the DNA to be separated from the proteins. The identity and quantity of the DNA fragments isolated can then be determined by polymerase chain reaction (PCR).
=== AMDS === Research overview: In this study there are several atomic-scale molecular dynamics simulations created to illustrate how ethanol affects biomembranes containing phospholipids. The phospholipid membrane systems are comparable to the model membranes above but it only consists of one phospholipid which is palmitoyl-oleoyl-phosphatidylcholine (POPC) or palmitoyl-oleoyl-phosphatidylethanolamine (POPE). The primary difference between the phosphatidylcholine (PC) and phosphatidylethanolamine (PE) is that the three methyl groups attached to the Nitrogen atom for the PC structure is replaced by three hydrogen groups. The overall purpose of this study is similar to the study described above determining the effects of ethanol on biomembranes and how it is able to increase disorder in the membrane interior region forming non-lamellar phases in phospholipids. The experimental method and analytical technique is quite different. In the previous study, it emphasized the NNR technique using a set of host phospholipids, exchanging lipids, ethanol, and cholesterol to create model membranes. An aqueous solution containing 5% ethanol (v/v) was maintained but the concentration of cholesterol was varied to prove how this sterol compound can inhibit the effects of ethanol (inducing a liquid-disorder phase or non-lamellar phases) which is depicted in the different plots of the equilibrium constant (K) versus the mol% of cholesterol for each model membrane.
The amine on AICAR is much less nucleophillic than its counterpart on GAR due to delocalization of electrons in AICAR through conjugation. Therefore, the N5 nucleophile of AIRCAR must be activated for the formylation reaction to occur. Histidine 268 and Lysine 267 have been found to be essential for catalysis and are conserved in all AICAR transformylase. Histidine 268 is involved in deprotonation of the N5 nucleophile of AICAR, whereas Lysine 267 is proposed to stabilize the tetrahedral intermediate.
Sources: en.wikipedia.org
Pattern hair loss, also known as androgenetic alopecia, is a hair loss condition that primarily affects the top and front of the scalp. In male-pattern hair loss, the hair loss typically presents itself as either a receding front hairline, loss of hair on the crown and vertex of the scalp, or a combination of both. Female-pattern hair loss typically presents as a diffuse thinning of the hair across the entire scalp. The condition is caused by a combination of male sex hormones and genetic factors. Some research has found evidence for the role of oxidative stress in hair loss, the microbiome of the scalp, genetics, and circulating androgens; particularly dihydrotestosterone. Men with early onset androgenic alopecia (before the age of 35) have been deemed the male phenotypic equivalent for polyendocrine metabolic ovarian syndrome. The cause of female pattern hair loss remains unclear; androgenetic alopecia for women is associated with an increased risk of polyendocrine metabolic ovarian syndrome. Management of hair loss may include styling the remaining hair in a creative manner to make hair loss less apparent or shaving one's head to improve the aesthetic aspect of the condition. Otherwise, common medical treatments include platelet-rich plasma, low-level laser therapy, minoxidil, finasteride, dutasteride, or hair transplant surgery. Use of finasteride and dutasteride in women is not well-studied and may result in birth defects if taken during pregnancy. By the age of 50, pattern hair loss affects about half of males and a quarter of females.
=== EC 1.18.1 With NAD+ or NADP+ as acceptor === EC 1.18.1.1: rubredoxin—NAD+ reductase EC 1.18.1.2: ferredoxin—NADP+ reductase EC 1.18.1.3: ferredoxin—NAD+ reductase EC 1.18.1.4: rubredoxin—NAD(P)+ reductase EC 1.18.1.5: Putidaredoxin—NAD+ reductase EC 1.18.1.6: adrenodoxin-NADP+ reductase EC 1.18.1.7: ferredoxin—NAD(P)+ reductase (naphthalene dioxygenase ferredoxin-specific) EC 1.18.1.8: Now EC 7.2.1.2, ferredoxin—NAD+ oxidoreductase (Na+-transporting)
Supratrochlear nerve and the supraorbital nerve from the ophthalmic division of the trigeminal nerve Greater occipital nerve (C2) posteriorly up to the vertex Lesser occipital nerve (C2) behind the ear Zygomaticotemporal nerve from the maxillary division of the trigeminal nerve supplying the hairless temple Auriculotemporal nerve from the mandibular division of the trigeminal nerve The innervation of scalp can be remembered using the mnemonic 'Z-GLASS' for Zygomaticotemporal nerve, Greater occipital nerve, Lesser occipital nerve, Auriculotemporal nerve, Supratrochlear nerve, and Supraorbital nerve. The motor innervation of the scalp, specifically, the occipitofrontalis muscle, is split into two main factions: the frontal belly or frontalis muscle is supplied by the temporal branch of facial nerve, while the occipital belly or occipitalis is supplied by the posterior auricular branch of facial nerve.
Carbohydrates are usually present, often in a mix of simple sugars like glucose and more complex oligosaccharides such as maltodextrin which are supposed to provide more sustained energy. Carbohydrates cause an increase in serotonin levels. These are used both to provide a sweet taste and fuel for exercise, though evidence for whether they actually enhance exercise performance is mixed. Protein supplements, usually in a palatable powdered form such as whey protein or rice protein, are also commonly used both for flavour and as a fuel for muscle growth and recovery. Electrolytes providing sodium, potassium and magnesium (and often others such as zinc, calcium, iron etc in smaller amounts) are often included to replace those lost due to sweating during heavy exercise, generally as a mixture of different salts, sometimes including exotic forms such as zinc monomethionine aspartate or calcium fructoborate which are supposed to be better absorbed or have other special properties. Electrolytes help the body perform homeostasis and prevent dehydration. Nitrate salts are commonly included (often as "beetroot extract") for their supposed benefits for endurance exercise. Sometimes this is achieved by using nitrate salts of other ingredients (e.g. arginine nitrate, creatine nitrate). Creatine, a natural chemical created in the kidneys and liver, is used supposedly to improve physical performance. It also promotes an increase in muscle growth. β-Alanine is a common ingredient found in 87% of leading pre-workout formulas.
Sources: en.wikipedia.org
It is a modified version of the natural hormone, with three amino acid changes and a fatty acid side chain added. These edits extend its half-life from minutes to about one week. The core receptor activity is retained.
Both deliver the same active peptide and act on the same receptor. The tablet includes an absorption enhancer because peptides are poorly taken up intact from the gut. Bioavailability of the oral route is substantially lower, so the two are not dose-equivalent.
No, it is entirely synthetic and does not occur in nature. Native GLP-1 is produced in the gut and pancreas, but the analog is manufactured by chemical synthesis or recombinant methods. Traces of the analog are not expected in people who never received it.
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.