incretin comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-07-22. Where a claim depends on a specific study, the study is described rather than over-claimed.
Published work supports the view that engaging two incretin receptors produces changes in glucose handling and body weight larger than those seen with single-receptor activation. Why that difference arises is not fully settled. Open questions include how much of the observed weight effect depends on central versus peripheral signaling, and whether the two receptors form interacting complexes. Most reported findings come from controlled trials and animal models, and translation between species is imperfect. Further research is expected to refine these points over time.
Tirzepatide is a synthetic peptide built from 39 amino acid residues. Its sequence is related to human glucose-dependent insulinotropic polypeptide, with modifications that include a C-terminal extension and a C20 fatty diacid joined through a linker. Those changes raise the molecule's affinity for serum albumin, which slows renal filtration and lengthens the time it stays in circulation. The free base has an average molecular mass near 4813.5 daltons. The compound is made by solid-phase peptide synthesis followed by chromatographic purification.
At the receptor level, tirzepatide activates both the glucose-dependent insulinotropic polypeptide receptor and the glucagon-like peptide-1 receptor. Both belong to the class B family of G protein-coupled receptors and signal largely through cyclic AMP accumulation. The compound binds the two receptors with differing affinity, and the pattern of signaling at each site is described in the literature as biased rather than simply proportional to occupancy. Tissues carrying these receptors include pancreatic islets, adipose tissue, the central nervous system, and the gastrointestinal tract. The relative weight of each receptor population in producing metabolic effects continues to be studied.
Identity and purity are usually established with reversed-phase high-performance liquid chromatography for the main peak and with mass spectrometry for the observed molecular mass. Peptide mapping after enzymatic digestion confirms the primary sequence, while amino acid analysis provides a quantitative composition check. Size-exclusion chromatography and ion-exchange chromatography are used to look for aggregates and charge variants. Water content, residual solvents, and counter-ion content are measured separately, since a lyophilised powder is often reported on an as-is basis unless a correction is applied.
Research-grade material circulates through suppliers that differ widely in documentation and testing practice, so a certificate of analysis is a starting point rather than proof of quality. Independent verification typically repeats chromatographic purity and mass confirmation on the received lot, and compares results against a retained reference standard. Regulatory status varies by jurisdiction, and a substance cleared as a medicine is not interchangeable with a research chemical of the same name. Open questions include how closely non-pharmaceutical lots match approved material in impurity profile and in aggregate content.
Solid tirzepatide is handled as a lyophilised, hygroscopic peptide powder that should be kept desiccated, protected from light, and stored frozen, typically at or below minus twenty degrees Celsius for long-term retention. Material left at ambient temperature for extended periods can take up moisture, which promotes aggregation and deamidation. Commercial liquid presentations are kept refrigerated between two and eight degrees Celsius and are not frozen. Reconstituted laboratory solutions are generally held cold and used within a short window because hydrolysis and oxidation continue slowly in solution.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C225H348N48O68 | 39-residue synthetic peptide |
| Average molecular mass | About 4813.5 Da | Free base form |
| Appearance | White to off-white powder | Solid after lyophilization |
| Solubility class | Freely soluble in water | Also soluble in neutral aqueous buffers |
| Typical storage | At or below -20 °C, desiccated | Protect from light and moisture |
固体状态的 tirzepatide 通常以冻干粉形式保存，推荐在低温、避光、干燥条件下存放，常见区间为 2 至 8 摄氏度，长期保存可考虑更低温度并避免反复冻融。冻融循环会导致肽链聚集或析出，从而影响后续定量结果。容器密封性与湿度控制同样是稳定性研究中反复强调的因素。
溶解操作一般使用注射用水或适宜的水性缓冲液，必要时加入少量助溶剂以改善溶解速度，但应避免剧烈涡旋振荡，因为剪切力可能促进聚集。配制后的溶液在冷藏条件下的稳定时间通常短于固体形态，具体时限取决于浓度、缓冲体系与容器材质。是否加入防腐成分，则取决于用途是否为多次取样。
Structure-activity work shows that fatty acid length, linker chemistry and the position of acylation all influence albumin affinity and receptor potency. Plasma protein binding exceeds 99 percent, which restricts distribution and slows renal clearance. Degradation proceeds largely through general proteolysis and fatty acid oxidation rather than cytochrome P450 metabolism, so exposure to common oxidative drug interactions is limited. Whether these clearance routes vary meaningfully between individuals is not fully established.
The molecule is a synthetic 39-amino-acid peptide whose backbone derives from the sequence of human glucose-dependent insulinotropic polypeptide, with several substitutions that raise metabolic stability and shift receptor preference. A C20 fatty diacid is attached through a short linker to a lysine side chain, a modification that increases binding to serum albumin. The reported monoisotopic mass is approximately 4813 Da. Near neutral pH the peptide carries a net negative charge, and the lipid tail makes the molecule markedly more hydrophobic than the unmodified parent sequence.
Receptor activation by tirzepatide raises intracellular cyclic AMP through Gs-coupled signalling at both targets. At the GLP-1 receptor the downstream effect includes glucose-dependent insulin release, suppressed glucagon secretion, delayed gastric emptying, and reduced appetite signalling in the hypothalamus. GIP receptor engagement adds insulinotropic activity and appears to influence lipid handling in adipose tissue. Because both receptors are stimulated at the same time, the pharmacological profile differs from that of selective GLP-1 receptor agonists, and the relative contribution of each arm remains an area of active investigation.
Clinical development proceeded through large phase 3 programmes in type 2 diabetes and in obesity or overweight with at least one weight-related comorbidity. Regulatory approvals followed in several jurisdictions for both indications. Weekly subcutaneous dosing reflects an elimination half-life of roughly five days. Open questions include the durability of metabolic effects after treatment stops, long-term cardiovascular and hepatic outcomes beyond completed trials, and whether the dual mechanism confers benefits independent of total receptor occupancy. Published literature continues to expand on these points. Substantial uncertainty remains about interindividual variability in response.
Tirzepatide is a synthetic linear peptide of 39 amino acids that acts as a dual agonist at the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. Its sequence derives from native GIP but incorporates non-natural residues and a C20 fatty diacid moiety linked to a lysine side chain. The lipophilic chain promotes albumin binding, which slows renal clearance and extends circulation time. The unmodified peptide has a molecular formula of C225H348N48O68 and a molecular mass near 4,813 daltons.
Tirzepatide is a synthetic peptide that activates both the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. This dual agonist profile distinguishes it from earlier incretin-based compounds that act on a single receptor. The molecule was engineered from the native GIP sequence and carries several non-natural residues that slow enzymatic breakdown. Researchers designed it to combine the insulinotropic effects of GIP signaling with the appetite and gastric-emptying effects associated with GLP-1 activation.
Development of tirzepatide took place under a research program that sought to test whether simultaneous engagement of two incretin receptors would produce greater metabolic effects than single-receptor agonism. Clinical trials were organized into the SURPASS series for type 2 diabetes and the SURMOUNT series for obesity and weight management. Regulatory clearance for type 2 diabetes came in 2022 in the United States, followed by approval for chronic weight management in 2023. The trial programs reported reductions in glycated hemoglobin and body weight relative to comparators, though long-term cardiovascular and durability data continue to accumulate.
== History == Remote Medical International is headquartered in Seattle, Washington, USA with employees based all over the globe. The company was founded by Andrew Cull, a remote area paramedic in 2003. Inc. Magazine has named RMI three times as one of the 500 fastest growing companies in the US. In 2011, Remote Medical International was listed in the "Top Twenty Places to Work" in Seattle. RMI has approximately 100 employees, most of which are medical professionals. In 2013, Remote Medical International received an $8 million investment from "Seattle-based Columbia Pacific Management, which already owns 23 hospitals in India, Malaysia, Vietnam and Indonesia through a related company, Columbia Asia." RMI partners with Columbia Asia and uses its hospital as a base of operations in Asia.
Low rate of homologous RNA recombination in paramyxoviruses probably results from this unusual genomic requirement for polyhexameric length (6n+0). Natural high genomic stability of SeV is a positive feature for it potential use as a vaccine vector or as an oncolytic agent. For any clinical or industrial applications, it is important that SeV genomic and inserted foreign genes would be expressed in a stable way. Due to SeV genetic stability, multiple serial passages of the virus construct in cell cultures or embryonated chicken eggs without drastic genomic changes are possible. SeV constructs are known to stably express a wide variety of heterologous antigens.
In 2010, Medpace acquired the Minneapolis medical-device consultancy Symbios and Germany's Medical Consulting Dr. Schlichtiger GmbH. In 2012 they acquired MediTech BV, a medical device consultancy based in the Netherlands.
The explosive trace detectors utilizing AFPs, known as Fido Explosives Detectors, were originally developed under the Defense Advanced Research Projects Agency (DARPA) Dog’s Nose program and is now produced by FLIR Systems. The current generation, provides broad-band trace explosive detection and weighs less than 3 lbs. The sensitivity is in the order of femtogram (1 × 10−15 grams). This is the only such technology in the field that can achieve such sensitivity.
Sources: en.wikipedia.org
== Further reading == Greenhalgh, D.G.; et al. (July–August 2006). "Instant cup of soup: design flaws increase risk of burns". J Burn Care Res. 27 (4): 476–481. doi:10.1097/01.BCR.0000226021.78139.49. PMID 16819351. S2CID 3690325. (registration required) Media related to Instant soups at Wikimedia Commons
Extreme UV (EUV or sometimes XUV) is characterized by a transition in the physics of interaction with matter. Wavelengths longer than about 30 nm interact mainly with the outer valence electrons of atoms, while wavelengths shorter than that interact mainly with inner-shell electrons and nuclei. The long end of the EUV spectrum is set by a prominent He+ spectral line at 30.4 nm. EUV is strongly absorbed by most known materials, but synthesizing multilayer optics that reflect up to about 50% of EUV radiation at normal incidence is possible. This technology was pioneered by the NIXT and MSSTA sounding rockets in the 1990s, and it has been used to make telescopes for solar imaging. See also the Extreme Ultraviolet Explorer satellite.
Lord Nelson (1758–1805) was preserved for two months in brandy and spirits of wine mixed with camphor and myrrh after which time the body was found to be in excellent condition and completely plastic. Various communist leaders have been embalmed and put on public display. Perhaps the most famous embalmed body of the 20th century is that of Vladimir Lenin, which continues to draw crowds decades after his death in 1924, and is seen in his Moscow mausoleum. Joseph Stalin was also embalmed and placed next to Lenin, but his body was buried in 1961 during de-Stalinization. Klement Gottwald of Czechoslovakia, who died just five days after attending Stalin's funeral, was embalmed and displayed in a mausoleum at National Monument in Vitkov in Prague. However, in 1962 due to political reasons, the body was removed and cremated. Bulgarian Georgi Dimitrov was embalmed and placed on display in the Sofia Georgi Dimitrov Mausoleum. After the fall of Communism in Bulgaria, his body was buried in 1990 in the Central cemetery of Sofia. Mongolia's Khorloogiin Choibalsan, Angola's Agostinho Neto, Romania's Gheorghe Gheorghiu-Dej and Guyana's Forbes Burnham were also embalmed by the same Russian team. Currently, embalmed communist leaders can also be found in the Mausoleum of Mao Zedong, the Ho Chi Minh Mausoleum, and the Kumsusan Palace of the Sun for Kim Il Sung and Kim Jong Il.
Also in 1893, Édouard Laguesse suggested that the islet cells of the pancreas, described as "little heaps of cells" by Paul Langerhans in 1869, might play a regulatory role in digestion. These cells were named Islets of Langerhans after the original discoverer. Soon after, it was established that the role of the pancreas in carbohydrate metabolism could be localized to the islets; Eugene Lindsay Opie (1901) confirmed this connection in relation to diabetes mellitus. In 1909, Belgian physician Jean de Mayer hypothesized that the islets secrete a substance that plays this metabolic role, and termed it insulin, from the Latin insula ('island'). Sir Edward Albert Sharpey-Schafer independently proposed the same in 1916, not knowing at the time that de Meyer had made the same suggestion a few years prior. The endocrine role of the pancreas in metabolism, and indeed the existence of insulin, was further clarified between 1921 and 1922 when a group of researchers in Toronto, including Frederick Banting, Charles Best, John MacLeod, and James Collip, were able to isolate and purify the extract.
Bradbury AF, Finnie MD, Smyth DG (1982). "Mechanism of C-terminal amide formation by pituitary enzymes". Nature. 298 (5875): 686–8. Bibcode:1982Natur.298..686B. doi:10.1038/298686a0. PMID 7099265. S2CID 4324776. Bradbury AF, Smyth DG (1987). "Enzyme-catalysed peptide amidation. Isolation of a stable intermediate formed by reaction of the amidating enzyme with an imino acid". Eur. J. Biochem. 169 (3): 579–84. doi:10.1111/j.1432-1033.1987.tb13648.x. PMID 3691506. Glembotski CC (1985). "Further characterization of the peptidyl alpha-amidating enzyme in rat anterior pituitary secretory granules". Arch. Biochem. Biophys. 241 (2): 673–83. doi:10.1016/0003-9861(85)90594-6. PMID 2994573. Katopodis AG, Ping D, May SW (1990). "A novel enzyme from bovine neurointermediate pituitary catalyzes dealkylation of alpha-hydroxyglycine derivatives, thereby functioning sequentially with peptidylglycine alpha-amidating monooxygenase in peptide amidation". Biochemistry. 29 (26): 6115–20. doi:10.1021/bi00478a001. PMID 2207061. Murthy AS, Keutmann HT, Eipper BA (1987). "Further characterization of peptidylglycine alpha-amidating monooxygenase from bovine neurointermediate pituitary". Mol. Endocrinol. 1 (4): 290–9. doi:10.1210/mend-1-4-290. PMID 3453894. Murthy AS, Mains RE, Eipper BA (1986). "Purification and characterization of peptidylglycine alpha-amidating monooxygenase from bovine neurointermediate pituitary". J. Biol. Chem. 261 (4): 1815–22. doi:10.1016/S0021-9258(17)36013-1. PMID 3944110.
Sources: en.wikipedia.org
The first In-N-Outs had a common design, placing the kitchen "stand" between two lanes of cars. The "front" lane is nearest the street and the "back" lane away from the street. This location design is known as a double drive-thru. A metal awning provides shade for several tables for customers desiring to park and eat, but there is no indoor dining. A walk-up window faces the parking area. These restaurants store food and supplies in a separate building, and it is not uncommon for a driver to be asked to wait a moment while employees carry supplies to the kitchen across the rear lane. This design is a popular image on In-N-Out ads and artwork, which often shows classic cars such as 1965 Mustangs and 1968 Firebirds visiting the original restaurants. The original Covina restaurant, located on Arrow Highway west of Grand Avenue, was forced to close in the early 1990s due to re-engineering and development of the area. A modern design, drive-up/dining room restaurant was built a few hundred feet away. The replacement building was considerably larger, occupying nearly half the area of the original building's lot. Newer In-N-Out restaurants are based on standardized templates or blueprints, which are selected based on available space and expected traffic levels. While the external appearance of its buildings may vary to meet local zoning and architectural requirements, the interior floor plan and decor in most recently constructed In-N-Out restaurants are identical.
The liver is a dark reddish brown, wedge-shaped organ with two lobes of unequal size and shape. A human liver normally weighs approximately 1.5 kilograms (3.3 pounds) and has a width of about 15 centimetres (6 inches). There is considerable size variation between individuals, with the standard reference range for men being 970–1,860 grams (2.14–4.10 lb) and for women 600–1,770 g (1.32–3.90 lb). It is both the heaviest internal organ and the largest gland in the human body. It is located in the right upper quadrant of the abdominal cavity, resting just below the diaphragm, to the right of the stomach, and overlying the gallbladder. The liver is connected to two large blood vessels: the hepatic artery and the portal vein. The hepatic artery carries oxygen-rich blood from the aorta via the celiac trunk, whereas the portal vein carries blood rich in digested nutrients from the entire gastrointestinal tract and also from the spleen and pancreas. These blood vessels subdivide into small capillaries known as liver sinusoids, which then lead to hepatic lobules.
=== Type II diabetes === Diabetes mellitus type 2 is a common disease that causes reduced insulin secretion and increased insulin resistance in the periphery. It results in increased blood glucose levels, or hyperglycemia, which can be fatal if untreated. Since Wnt signaling is involved in insulin sensitivity, malfunctioning of its pathway could be involved. Overexpression of Wnt5b, for instance, may increase susceptibility due to its role in adipogenesis, since obesity and type II diabetes have high comorbidity. Wnt signaling is a strong activator of mitochondrial biogenesis. This leads to increased production of reactive oxygen species (ROS) known to cause DNA and cellular damage. This ROS-induced damage is significant because it can cause acute hepatic insulin resistance, or injury-induced insulin resistance. Mutations in Wnt signaling-associated transcription factors, such as TCF7L2, are linked to increased susceptibility.
== Notable members == General Lloyd Austin (born 1953), Commanding General of XVIII Airborne Corps, Commanding General of CENTCOM, 28th Secretary of Defense Master Sergeant Roy P. Benavidez (Medal of Honor Recipient), Vietnam War General of the Army Omar Bradley Moffatt Burriss, politician from South Carolina Jason Crow, member of the US House of Representatives for Colorado's 6th congressional district Fashion critic/choreographer Bruce Darnell (born 1957) Louisiana governor John Bel Edwards (born 1966) LTG Michael Flynn (born 1958), former commander of the 313th Military Intelligence Battalion and Division G-2 Actor Dennis Franz (born 1944) Leonard A. Funk Jr. 508th P.I.R, WW2 Medal of Honor recipient and credited as the most highly decorated US Army Airborne soldier of the Second World War Lieutenant General James M. Gavin Colonel Chris Gibson (born 1964), former commander of the 2d Battalion, 325th Infantry Regiment, and later commander of the division's 2d Brigade Combat Team, former New York Congressman Melvin O. Handrich (Medal of Honor Recipient, Korean War; First Special Service Force and Company I, 508th Parachute Infantry in World War II) Mark T. Vande Hei (born 1966), Col (En) (ret.), prior engineer platoon leader in 3/325th Infantry Real life Goodfellas movie mobster, Henry Hill served as a cook in the Division from 1960 to 1963. Sean D. Jordan, judge Clint Lorance (born 1984), officer convicted of second-degree murder for battlefield deaths; pardoned Jacklyn H.
== Clinical significance == Mutations of the ADH5 gene and ALDH2 gene cause AMED syndrome, an autosomal recessive digenic multisystem disorder characterized by global developmental delay with impaired intellectual development, short stature, growth impairment and early development of myelodysplastic syndrome and bone marrow failure. The syndrome was first described in 2020.
Sources: en.wikipedia.org
It is a synthetic peptide and a dual agonist of two incretin receptors. It is not a small molecule, and it is not structurally related to the older single-receptor peptide agonists.
The C20 fatty diacid promotes tight binding to serum albumin. That binding reduces renal clearance and extends circulation time compared with an unmodified peptide of similar length.
It is not fully established. Studies indicate that both receptors contribute to the observed effects, but the exact split between the two signaling pathways in humans remains an open question.
It is normally kept frozen, desiccated, and away from light, with brief warming to room temperature before opening to limit condensation. Repeated freeze-thaw cycles are avoided because they stress the peptide. Once in solution, the material is held cold and used promptly.