Everything below concerns GLP-1 receptor. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-07-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
Tirzepatide activates both the glucose-dependent insulinotropic polypeptide receptor and the glucagon-like peptide-1 receptor, making it a dual agonist rather than a selective agent. Engagement of the GLP-1 receptor is linked to glucose-dependent insulin release, slower gastric emptying, and reduced appetite signalling. The relative contribution of the GIP arm remains an active research question; proposed roles include improved insulin sensitivity and altered adipose tissue handling. Receptor occupancy studies suggest the molecule interacts with both targets at circulating concentrations achieved during therapy.
Development began in the 2010s, when researchers modified a GIP-based scaffold to add GLP-1 activity and then attached the fatty diacid to lengthen its half-life. Clinical evaluation proceeded through large phase 3 programmes in type 2 diabetes and in obesity, and regulators in the United States cleared the compound for type 2 diabetes in 2022 and for chronic weight management in 2023. Several cardiovascular and metabolic outcome studies are still reporting, so the picture of long-term benefit and risk is incomplete. Approvals in other regions followed on different timelines.
Tirzepatide is a synthetic peptide of 39 amino acids that carries a C20 fatty diacid side chain attached through a linker. Its molecular formula is C225H348N48O68, and its molecular weight is about 4813 daltons. The compound belongs to the incretin mimetic class and is administered by subcutaneous injection. The fatty acid chain promotes binding to serum albumin, which slows renal clearance and extends the circulation time of the molecule. It was identified during screening of sequences derived from glucose-dependent insulinotropic polypeptide.
Identity and purity are assessed by reversed-phase high-performance liquid chromatography, with mass confirmation by electrospray ionisation mass spectrometry. Peptide mapping after enzymatic digestion verifies the primary sequence. Size-exclusion chromatography quantifies aggregates, while circular dichroism provides a secondary-structure fingerprint. Bioanalytical quantification in plasma uses immunoassay or LC-MS/MS. Reported purity for research-grade lots is commonly 95 percent or higher, and residual water content is checked by Karl Fischer titration.
As a peptide, tirzepatide is handled as a lyophilised solid in research settings and as a preserved solution in finished products. Aqueous solubility is pH dependent and reaches a minimum near the isoelectric point, which lies close to pH 5.4. Stock solutions are typically prepared in neutral or slightly basic buffer to limit precipitation. The solid is hygroscopic and should be equilibrated to room temperature before opening so that condensation does not form on the powder surface.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C225H348N48O68 | Peptide backbone with a fatty diacid chain |
| Molecular weight | About 4813 Da | Calculated from the formula |
| Receptor targets | GIP and GLP-1 receptors | Dual agonist activity at both sites |
| Route of administration | Subcutaneous injection | No approved oral form at present |
| Elimination half-life | About 5 days | Supports extended intervals between administrations |
脂肪酸侧链的存在使该肽与血浆白蛋白结合能力增强，从而延长循环半衰期，支持每周一次给药的用药间隔。白蛋白结合同时改变组织分布特征，减慢肾脏清除速度。该设计思路在多种长效肽类药物中被反复采用，属于既定的药代动力学策略。
该化合物的名称与结构由国际非专利名称体系统一维持，不同文献中出现的同义写法主要在拼写顺序或盐形式描述上不同。研究者通常通过受体结合实验、细胞内环磷酸腺苷积累测定以及动物模型来确认其双激动活性。相当一部分分子层面的细节——例如两条受体通路之间的信号交叉作用——尚处于开放问题状态。
Research and analytical settings increasingly require documentation of peptide origin and chain of custody. Certificate of analysis documents typically report purity by chromatographic area, mass confirmation, appearance, and residual solvent or counterion content. Independent verification by an accredited laboratory is common when a material will be used in a regulated study. Open questions remain about how well compendial methods transfer between laboratories, and about which impurity thresholds are meaningful for materials not intended for clinical use.
Peptide-based pharmaceutical products such as tirzepatide require controlled temperature management to preserve structural integrity. Manufacturer labeling generally specifies refrigeration at 2 to 8 degrees Celsius before first use, with protection from light and freezing. Exposure to repeated temperature cycling can promote aggregation or deamidation, which alters the analytical profile even when the visible solution appears unchanged. Once a product is in use, the permitted storage window and temperature range are defined by the specific labeled presentation rather than by general peptide rules.
Identity and purity assessment of tirzepatide relies primarily on reversed-phase high-performance liquid chromatography coupled with ultraviolet detection. Mass spectrometry, often in electrospray ionization mode, confirms the molecular mass and detects sequence-related impurities. Peptide mapping after enzymatic digestion provides residue-level confirmation of the backbone. Each method addresses a different question: chromatography for purity and related substances, mass measurement for identity, and mapping for sequence fidelity. No single technique covers all three.
The peptide shares degradation routes common to modified peptides: deamidation of asparagine and glutamine residues, oxidation of methionine, and backbone hydrolysis under extreme pH. Lyophilized material is generally more stable than a solution, and residual water content directly affects the rate of hydrolysis. In liquid form, aggregation and visible particles can appear after agitation or repeated freeze-thaw cycles. Stability studies therefore track monomer content, aggregate content, and potency over months under defined temperature and humidity.
Cold-chain handling is standard for formulated product, with dry powder stored frozen and ready-to-use solutions refrigerated. Light exposure is minimized because photodegradation of certain amino acid side chains is possible. Shipping and temperature-excursion studies are used to establish whether short deviations affect quality attributes. Documentation supplied with research material usually includes a certificate of analysis listing purity, identity confirmation, and water or residual solvent content. Users are expected to confirm that material meets the stated specification before use.
Identity and purity of tirzepatide are assessed mainly by reversed-phase high-performance liquid chromatography with ultraviolet detection, often paired with mass spectrometry. Because the molecule carries several modifications, gradient conditions are adjusted to resolve the intact peptide from deamidation and oxidation products. Enzymatic digestion followed by peptide mapping confirms the primary sequence and locates specific modifications. Quantitation in biological matrices typically uses liquid chromatography with tandem mass spectrometry after solid-phase extraction. Immunoassays are used less often, since antibody cross-reactivity with closely related peptides can bias results.
Tirzepatide is a synthetic peptide that acts as a dual agonist at the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. The molecule contains 39 amino acids and features a C20 fatty diacid moiety attached via a linker, which promotes albumin binding and extends its circulating half-life. Its sequence incorporates non-natural amino acids and modifications that reduce susceptibility to degradation by dipeptidyl peptidase-4. This dual receptor activity distinguishes it from selective GLP-1 receptor agonists.
The GIP receptor is expressed in pancreatic islets, adipose tissue, and the central nervous system, while GLP-1 receptors are found in pancreatic islets, the gastrointestinal tract, and the brain. Activation of both receptors can enhance glucose-dependent insulin secretion and reduce glucagon release. The relative contribution of each receptor to the overall pharmacological effect remains an area of ongoing investigation. Preclinical studies suggest that GIP receptor agonism may modulate appetite and energy balance, but the precise mechanisms in humans are not fully established.
Gusts of up to 82 mph are reported, with yellow weather warnings in place for Scotland, and much of Northern Ireland and northern England. 22 December Strong winds continue to cause disruption in parts of the UK, with Heathrow Airport cancelling around 100 flights. A BBC News investigation discovers that a Church of England priest at the centre of a sexual abuse case was twice reappointed to a senior role during Archbishop of York Stephen Cottrell's time as Bishop of Chelmsford. In response, Cottrell says he regrets the handling of the incident. 23 December Revised Office for National Statistics data shows economic growth was at 0% between July and September. A number of Morrisons stores have been beset with technical problems regarding discounts and deliveries. Chocolate manufacturer Cadbury is stripped of its Royal Warrant of Appointment after being included on the list of Appointments since 1854. 24 December Two NHS hospitals in London are reported to be trialling artificial intelligence (AI) in order to detect signs of type 2 diabetes in patients. The UK government announces that the UK motor industry is being consulted on how the phasing out of petrol and diesel engines by 2030 would work. The Met Office forecasts mild and dry weather for Christmas Day throughout much of the UK. 25 December Off Dunkirk on the north coast of France, French authorities rescue 30 people from a small boat, whilst allowing those wishing to cross the Channel to England, to continue into British waters to be taken into the custody of British authorities.
== Ecology == The diet of the arapaima consists of fish, crustaceans, fruits, seeds, insects, and small land animals that walk near the shore (such as mammals and birds). The fish is an air breather, using its labyrinth organ, which is rich in blood vessels and opens into the fish's mouth, an advantage in oxygen-deprived water that is often found in the Amazon River. This fish is able to survive in oxbow lakes with dissolved oxygen as low as 0.5 ppm. In the wetlands of the Araguaia, one of the most important refuges for this species, it is the top predator in such lakes during the low-water season, when the lakes are isolated from the rivers and oxygen levels drop, rendering its prey lethargic and vulnerable. Arapaima may leap out of the water if they feel constrained by their environment or harassed.
Another key to finding the correct structure of DNA was the so-called Chargaff ratios, experimentally determined ratios of the nucleotide subunits of DNA: the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine. A visit by Erwin Chargaff to England, in 1952, reinforced the salience of this important fact for Watson and Crick. The significance of these ratios for the structure of DNA were not recognised until Watson, persisting in building structural models, realised that A:T and C:G pairs are structurally similar. In particular, the length of each base pair is the same. Chargaff had also pointed out to Watson that, in the aqueous, saline environment of the cell, the predominant tautomers of the pyrimidine (C and T) bases would be the amine and keto configurations of cytosine and thymine, rather than the imino and enol forms that Crick and Watson had assumed. They consulted Jerry Donohue who confirmed the most likely structures of the nucleotide bases. The base pairs are held together by hydrogen bonds, the same non-covalent interaction that stabilise the protein α-helix. The correct structures were essential for the positioning of the hydrogen bonds. These insights led Watson to deduce the true biological relationships of the A:T and C:G pairs.
=== Forum === A major feature of Planet Half-Life, and all other Planet sites was its public forum. These forums included boards ranging from general discussion to technical help. In August 2007, the forums changed format to comply with GameSpy's ForumPlanet standard (the IGN SnowBoards system), removing some outdated features and adding many new ones, such as a dynamic news box that streams in late-breaking news from not only PHL, but all other planet sites as well. This also changed the registration process for the forum, from a per-planet account basis to a network-wide, global account basis. At this time Planet Half-Life's sister sites Planet Fortress and CS.net were officially unsupported and their forums were to be merged into PHL's, although this process lasted over a year before it was complete.
== Background == Plants and animals alike both use small polypeptides for signaling in cell-to-cell communication. CLAVATA3/Embryo Surrounding Region-Related, also known as a plant peptide hormone, signaling is important for cell to cell signaling but also long distance communication. These two actions are especially important for plant cells because they are stationary and must perform cell expansion. In multicellular organisms, cell-to-cell communication has been found to be very crucial for many growth processes that occur inside the organism. The 12 or 13 amino acid polypeptides are the mature forms of the CLE proteins that are derived from the conserved CLE domains. More and more CLE genes are being identified with more research being conducted in this area. CLE genes have not only been found in seed plants but also in lycophytes, bryophytes, and green algae.
Sources: en.wikipedia.org
=== Separation of powers of the federal and state governments === The federation agreement (Perjanjian Persekutuan) set the powers of the federal and state governments. Financial matters must be handled by the respective states. The Sultan was given full power on religious issues and Malay customs. Foreign policy and defence continued to be administered by the British government. The federation agreement was made the Constitution of the Federation of Malaya and officially declared on 1 February 1948.
The global annual production of freshwater prawns (excluding crayfish and crabs) in 2007 was about 460,000 tonnes, exceeding 1.86 billion dollars. Additionally, China produced about 370,000 tonnes of Chinese river crab. In addition astaciculture is the freshwater farming of crayfish (mostly in the US, Australia, and Europe).
The War of 1812 coincided with the War of the Sixth Coalition. Historians in the United States and Canada see it as a war in its own right, while Europeans often see it as a minor theatre of the Napoleonic Wars. The United States declared war on Britain due to a variety of reasons, including British support for Native Americans resisting US settler expansion, interference with American merchant shipping, the impressment of Royal Navy deserters from US merchantmen, and expansionist American desires to occupy Canada. France had interfered with American shipping as well, and the United States had considered declaring war on France. The war ended in a military stalemate under the Treaty of Ghent, which took effect in early 1815 when Napoleon was still in Elba and returned the pre-war boundaries.
As of 2025, the reasons for the higher mortality in men are unknown. It has been speculated that men have different dementia risk factors than women, like traumatic brain injury. Aspiration pneumonia is the most frequent immediate cause of death brought by AD. While the reasons behind the lower prevalence of cancer in AD patients remain unclear, some researchers hypothesize that biological mechanisms shared by both diseases might play a role. However, this requires further investigation.
== Research == Research has identified at least one other possible marker that may appear earlier and exclusively during pregnancy. For example, early pregnancy factor (EPF) can be detected in blood within 48 hours of fertilization, rather than after implantation. However, its reliable use as a pregnancy test remains unclear as studies have shown its presence in physiological situations besides pregnancy, and its application to humans remains limited.
Sources: en.wikipedia.org
== Paralympic Games == Cheating at the Paralympic Games – in the 2000 Summer Paralympics, athletes from Spain competed and won the gold medal in the Basketball ID event despite the majority of players not having an intellectual disability. The fallout from this scandal saw all events for athletes with intellectual disabilities removed from the next two Summer Paralympics.
Confirmatory testing: compounds that were found active against the selected target are re-tested using the same assay conditions used during the HTS to make sure that the activity is reproducible. Dose response curve: the compound is tested over a range of concentrations to determine the concentration that results in half maximal binding or activity (IC50 or EC50 value respectively). Orthogonal testing: confirmed hits are assayed using a different assay which is usually closer to the target physiological condition or using a different technology. Secondary screening: confirmed hits are tested in a functional cellular assay to determine efficacy. Synthetic tractability: medicinal chemists evaluate compounds according to their synthesis feasibility and other parameters such as up-scaling or cost of goods. Biophysical testing: nuclear magnetic resonance (NMR), isothermal titration calorimetry (ITC), dynamic light scattering (DLS), surface plasmon resonance (SPR), dual polarisation interferometry (DPI), microscale thermophoresis (MST) are commonly used to assess whether the compound binds effectively to the target, the kinetics, thermodynamics, and stoichiometry of binding, any associated conformational change and to rule out promiscuous binding. Hit ranking and clustering: Confirmed hit compounds are then ranked according to the various hit confirmation experiments. Freedom to operate evaluation: hit structures are checked in specialized databases to determine if they are patentable.
Complexes containing CS are known but uncommon. The rarity of such complexes is partly attributable to the fact that the obvious source material, carbon monosulfide, is unstable. Thus, the synthesis of thiocarbonyl complexes requires indirect routes, such as the reaction of disodium tetracarbonylferrate with thiophosgene:
Bromelain, a concentrate of proteolytic enzymes from the pineapple plant, is used in medicine. It is approved in the European Union for the debridement (removal of eschar, that is dead and damaged tissue) of severe burn wounds under the brand name Nexobrid. It was developed by MediWound. The medicine has been granted orphan drug status by the European Medicines Agency (EMA). In other contexts, bromelain has been researched for possible anti-inflammatory effects in treating a range of conditions or diseases, but results of these studies are mixed and regarded as preliminary. In December 2022, anacaulase-bcdb (Nexobrid) was approved for medical use in the United States.
Strontium is a chemical element; it has symbol Sr and atomic number 38. An alkaline earth metal, it is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to air. Strontium has physical and chemical properties similar to those of its two vertical neighbors in the periodic table, calcium and barium. It occurs naturally mainly in the minerals celestine and strontianite, and is mostly mined from these. Both strontium and strontianite are named after Strontian, a village in Scotland near which the mineral was discovered in 1790 by Adair Crawford and William Cruickshank. It was identified as a new element the next year from its crimson-red flame test color. Strontium was first isolated as a metal in 1808 by Humphry Davy using the then newly discovered process of electrolysis. During the 19th century, strontium was mostly used in the production of sugar from sugar beets (see strontian process). At the peak of production of television cathode-ray tubes, as much as 75% of strontium consumption in the United States was used for the faceplate glass. With the replacement of cathode-ray tubes with other display methods, consumption of strontium has dramatically declined. While natural strontium (which is mostly the isotope strontium-88) is stable, the synthetic strontium-90 is radioactive and is one of the most dangerous components of nuclear fallout, as strontium is absorbed by the body in a similar manner to calcium. Natural stable strontium is not hazardous to health at low levels.
Sources: en.wikipedia.org
It is a synthetic 39-amino-acid peptide that acts on two incretin receptors, the GIP receptor and the GLP-1 receptor. It is given by subcutaneous injection and has a circulating half-life of roughly five days. It is not a small molecule and is not absorbed usefully from the gut in conventional oral form.
Selective agents act on one receptor, while tirzepatide engages both GIP and GLP-1 receptors. The added GIP activity may contribute effects on insulin sensitivity and on fat metabolism. Whether the dual action produces meaningful clinical advantages beyond differences in potency is still being examined.
The downstream consequences of GIP receptor activation are not fully characterised in humans. It is also unclear how much each receptor contributes to appetite reduction and to shifts in body composition. Published work describes associations and proposed pathways rather than settled causal chains.
Solid material is normally kept frozen at about -20 degrees Celsius, desiccated and protected from light. Solutions are held cold and used within a defined window because degradation products accumulate over time.