A practical reference on incretin: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-12-30 and is reviewed periodically as new material appears.
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.
GLP-1 receptors are expressed on pancreatic beta cells, in the gut, and in several brain regions. Receptor activation raises cyclic AMP, enhances glucose-dependent insulin secretion, and suppresses glucagon release when blood glucose is high. Effects on gastric emptying and on hypothalamic appetite circuits reduce energy intake. Because insulin release remains glucose-dependent, the risk of hypoglycemia is low when the drug is used alone. The precise contribution of each pathway to body weight change in humans remains an area of active investigation.
Clinical studies of semaglutide generally measure glycated hemoglobin, fasting plasma glucose, body weight, and composite cardiovascular endpoints. The SUSTAIN program enrolled adults with type 2 diabetes, while the STEP program focused on obesity without diabetes. Administration follows a stepwise escalation schedule designed to limit gastrointestinal effects during the first weeks. Reported outcomes include mean percentage weight change, the proportion of participants reaching defined weight-loss thresholds, and rates of nausea, vomiting, and diarrhea. Long-term data on durability after treatment stops are still limited and remain a topic of ongoing research.
| Property | Value | Notes |
|---|---|---|
| Molecular class | 31-amino-acid peptide | Modified glucagon-like peptide-1 analogue |
| Molecular mass | approximately 4114 Da | Calculated for the free peptide backbone |
| Appearance | white to off-white powder | Typical of purified lyophilised peptide batches |
| Solubility class | freely soluble in water | Aqueous solubility improves at slightly alkaline pH |
| Typical storage | -20 degrees Celsius, dry, dark | Protect from repeated freeze-thaw cycles |
Ball, Jennifer (2005). Byzantine Dress: Representations of Secular Dress in Eighth- to Twelfth-Century Painting. The New Middle Ages (1st ed.). New York: Palgrave Macmillan. ISBN 978-1-4039-6700-8. Sarris, Peter. "The Eastern Roman Empire from Constantine to Heraclius (306–641)". In Mango (2002), pp. 19–70.
==== Antibody target for animal model of glomerulonephritis ==== Single tail vein intravenous injection of antibody (OX7 mouse monoclonal IgG) against Thy1.1 in rats is used as a standard animal model to produce experimental mesangioproliferative glomerulonephritis which is popularly known in the field of nephrology as antiThy1 GN.
=== Historical use by government agencies === Beginning in the 1950s, the US Central Intelligence Agency (CIA) began a research program code-named Project MKUltra. The CIA introduced LSD to the United States, purchasing the entire world's supply for $240,000 and propagating the LSD through CIA front organizations to American hospitals, clinics, prisons, and research centers. Experiments included administering LSD to CIA employees, military personnel, doctors, other government agents, prostitutes, mentally ill patients, and members of the general public to study their reactions (usually without the subjects' knowledge), the most well-known example of this being Operation Midnight Climax. The project was revealed in the US congressional Rockefeller Commission report in 1975. However, the extent of the experiments conducted under Project MKUltra are still mostly unknown, as acting CIA director Richard Helms destroyed many of the key documents related to MKUltra in 1973. According to declassified CIA documents, it's possible that the American agency spread LSD amongst civilians in Europe in the 1950s. LSD was also one of several psychoactive substances evaluated by the U.S. Army Chemical Corps as possible non-lethal incapacitants in the Edgewood Arsenal human experiments.
The Journal of the American Society for Mass Spectrometry is a monthly peer-reviewed scientific journal published by ACS Publications since 2020. From 2011 to 2019 it was published by Springer Science+Business Media and prior to that by Elsevier. It is the official publication of the American Society for Mass Spectrometry and freely available to members. The journal covers all aspects of mass spectrometry. Until 2015, Michael L. Gross (Washington University in St. Louis) was the founding editor-in-chief; he was succeeded by Joseph A. Loo (University of California, Los Angeles). The journal is abstracted and indexed in MEDLINE.
Sources: en.wikipedia.org
The attitude that Mexico takes in the present eventuality is based on the fact that our determination stems from a need for legitimate defense. We know the limits of our military resources and we know that, given the enormity of the international masses in conflict, our role in the current conflict will not consist of extra-continental war actions, for which we are not prepared. "Simulated neutrality" had been left behind and Mexico was explicitly on the side of the Allies as a belligerent country. Lázaro Cárdenas was appointed Secretary of Defense, the National Military Service (SMN) was created, the United States delivered armaments to improve the capacity of the Mexican army, and the properties of German, Japanese and Italian citizens were seized. Even so, Avila Camacho indicated that Mexico's role in the conflict was not on the battlefield, but to prepare his defenses and provide resources to its new allies. Between June and September 1942 the U-Boats sank four more ships: Tuxpam, Las Choapas, Oaxaca and Amatlán. In view of this situation, the United States, under the pretext of the possibility of aggression by Japan on the coasts of the Pacific Ocean, began discreet negotiations to be allowed to install a military base on the Baja California peninsula; according to historian Humberto Musacchio, that there was speculation that he might have tried to occupy that part of Mexican territory without success.
==== VEGF ==== Vascular endothelial growth factor (VEGF) has been demonstrated to be a major contributor to angiogenesis, increasing the number of capillaries in a given network. Initial in vitro studies demonstrated bovine capillary endothelial cells will proliferate and show signs of tube structures upon stimulation by VEGF and bFGF, although the results were more pronounced with VEGF. Upregulation of VEGF is a major component of the physiological response to exercise and its role in angiogenesis is suspected to be a possible treatment in vascular injuries. In vitro studies clearly demonstrate that VEGF is a potent stimulator of angiogenesis because, in the presence of this growth factor, plated endothelial cells will proliferate and migrate, eventually forming tube structures resembling capillaries. VEGF causes a massive signaling cascade in endothelial cells. Binding to VEGF receptor-2 (VEGFR-2) starts a tyrosine kinase signaling cascade that stimulates the production of factors that variously stimulate vessel permeability (eNOS, producing NO), proliferation/survival (bFGF), migration (ICAMs/VCAMs/MMPs) and finally differentiation into mature blood vessels. Mechanically, VEGF is upregulated with muscle contractions as a result of increased blood flow to affected areas. The increased flow also causes a large increase in the mRNA production of VEGF receptors 1 and 2. The increase in receptor production means muscle contractions could cause upregulation of the signaling cascade relating to angiogenesis.
== Skin == The stratum corneum – the outermost layer of the epidermis – is composed of terminally differentiated and enucleated corneocytes within a lipid matrix. Together with cholesterol and ceramides, free fatty acids form a water-impermeable barrier that prevents evaporative water loss. Generally, the epidermal lipid matrix is composed of an equimolar mixture of ceramides (about 50% by weight), cholesterol (25%), and free fatty acids (15%). Saturated fatty acids 16 and 18 carbons in length are the dominant types in the epidermis, while unsaturated fatty acids and saturated fatty acids of various other lengths are also present. The relative abundance of the different fatty acids in the epidermis is dependent on the body site the skin is covering. There are also characteristic epidermal fatty acid alterations that occur in psoriasis, atopic dermatitis, and other inflammatory conditions.
Sources: en.wikipedia.org
It is a glucagon-like peptide-1 receptor agonist, often grouped with the incretin mimetics. Its backbone is modified from the human hormone to resist enzymatic degradation and to bind albumin. These two features distinguish it from the native peptide.
No. It shares high sequence identity but carries non-natural modifications that alter its stability and clearance. The naturally occurring hormone is broken down within minutes, while the synthetic analogue circulates far longer.
Attachment to serum albumin reduces renal filtration of the peptide and shields it from enzymatic breakdown. The consequence is a much longer interval between administrations than unmodified peptides allow. The precise contribution of binding affinity to overall duration is still being quantified.
It is given either as a once-weekly subcutaneous injection or as an oral tablet taken once daily. The two forms use different absorption strategies, so they are not interchangeable on a milligram-for-milligram basis.