phase 2 trial raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-02-19 and is reviewed periodically as new material appears.
Interpretation depends on study phase and duration. Phase 2 programs are powered for weight and safety signals, not for cardiovascular or renal outcomes, which require event-driven designs. Gastrointestinal events such as nausea, diarrhea, vomiting, and constipation are the most frequently reported adverse effects and tend to cluster around dose escalation. Small increases in heart rate have been described. Because follow-up after treatment discontinuation is limited, questions about weight regain and durability are open rather than answered.
Trial reports for this compound rely on a small set of repeated measures. Body weight is normally expressed as percent change from baseline at a fixed week, with absolute kilograms given secondarily. Glycemic endpoints include HbA1c, fasting glucose, and, in some protocols, continuous glucose monitoring summaries. Imaging endpoints such as MRI-derived proton density fat fraction quantify liver fat. Standardization matters because a percent change and a categorical responder analysis can tell different stories about the same dataset.
Body composition is assessed with dual-energy X-ray absorptiometry or comparable methods, which separate fat mass from lean mass. Reported losses include both compartments, and the ratio between them is a subject of ongoing analysis rather than a settled result. Waist circumference, blood pressure, and lipid panels are collected as supporting measures. Resting energy expenditure and substrate oxidation are measured in smaller mechanistic studies, where glucagon receptor activity is expected to matter. These substudies are typically short and small, so their findings carry wide uncertainty.
The intended pharmacology combines three signals in one molecule. GLP-1 receptor activation reduces appetite and slows gastric emptying, effects already exploited by approved incretin-based therapies. GIP receptor engagement is associated with improved insulin sensitivity and with direct effects on adipose tissue, although how much it contributes to overall outcomes is still debated. Glucagon receptor agonism raises energy expenditure and supports hepatic lipid handling, a mechanism that also tends to increase glucose output. The triple profile is hypothesized to produce a larger metabolic effect than single or dual agonism, but the relative weight of each receptor in humans is not settled.
Human evidence remains limited to controlled studies. A phase 2 trial in adults with obesity reported large, dose-dependent reductions in body weight over 48 weeks, with gastrointestinal events as the most frequently recorded adverse effect. Phase 3 programs designated TRIUMPH, for obesity, and TRANSCEND, for type 2 diabetes, are intended to confirm efficacy and to characterize safety in larger populations. Related studies are examining conditions such as knee osteoarthritis in people with obesity and metabolic liver disease. Open questions include long-term tolerability, effects on lean mass, and what happens after treatment is stopped.
| Property | Value | Notes |
|---|---|---|
| Trial design | Randomized, double-blind, placebo-controlled | Frequently includes dose-escalation arms |
| Weight endpoint | Percent change from baseline | Reported at a prespecified week |
| Liver fat endpoint | MRI proton density fat fraction | Non-invasive imaging measure |
| Body composition method | Dual-energy X-ray absorptiometry | Separates fat mass from lean mass |
| Common adverse events | Nausea, diarrhea, vomiting | Reported most often during dose escalation |
retatrutide 是一种人工合成的多肽，设计目标是同时作用于 GIP、GLP-1 与胰高血糖素三种受体。这种三重激动设计试图把多条代谢通路的调节整合进单一分子，而不是只依赖一种肠促胰素受体。分子骨架以天然肽序列为基础，经过非天然氨基酸替换和脂肪酸侧链修饰，以获得更长的作用时间。该方向属于多受体激动剂研究的一部分，与双重激动剂的工作并行推进。
三种受体在能量平衡中的分工并不相同：GLP-1 与 GIP 受体主要参与胰岛素分泌和食欲调节，胰高血糖素受体则与能量消耗及肝糖输出相关。同时激活三者可能产生叠加效应，也可能出现相互制约，具体结果取决于受体亲和力与组织分布。这种组合在理论上可能同时影响体重与血糖指标，但协同关系的细节仍处在研究阶段。
Retatrutide is an investigational synthetic peptide designed to activate three distinct receptor systems within a single molecule. Its pharmacological profile combines activity at the glucose-dependent insulinotropic polypeptide receptor, the glucagon-like peptide-1 receptor, and the glucagon receptor. This arrangement places it within a broader class of agents often described as multi-agonists, which contrast with compounds that engage one or two targets. Research interest centers on whether simultaneous signaling produces effects that single-receptor agonists cannot achieve alone. A single molecular entity also simplifies manufacturing and delivery logistics compared with combining separate agents.
Mechanistic proposals link each receptor to a different physiological role. Activation of the glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptors is associated with reduced appetite, slower gastric emptying, and glucose-dependent insulin release. Glucagon receptor signaling, by contrast, is associated with increased energy expenditure and altered lipid handling, though it can also raise blood glucose. The design intent is to balance these contributions so that weight reduction is enhanced without unacceptable glycemic trade-offs. How well that balance holds across individuals is not fully resolved.
Published information places retatrutide in clinical development rather than on the market as an approved therapy. Early-stage and mid-stage trials have examined tolerability and changes in body weight, and larger studies continue to report results over time. Open questions include the durability of effects after treatment stops, the composition of weight lost, and cardiovascular outcomes over long periods. Statements about definitive benefit should therefore be treated as provisional. Regulatory status varies by jurisdiction and changes as applications are reviewed.
Iodine-131 (131I, I-131) is a radioisotope of iodine discovered by Glenn Seaborg and John Livingood in 1938 at the University of California, Berkeley. It has a radioactive decay half-life of about eight days. It is associated with nuclear energy, medical diagnostic and treatment procedures, and natural gas production. It also plays a major role as a radioactive isotope present in nuclear fission products, and was a significant contributor to the health hazards from open-air atomic bomb testing in the 1950s, and from the Chernobyl disaster, as well as being a large fraction of the contamination hazard in the first weeks in the Fukushima nuclear crisis. This is because 131I is a major fission product of uranium and plutonium, comprising nearly 3% of the total products of fission (see fission product yield). Due to its beta decay, iodine-131 causes mutation and death in cells that it penetrates, and other cells up to several millimeters away. For this reason, high doses of the isotope are sometimes less dangerous than low doses, since they tend to kill thyroid tissues that would otherwise become cancerous as a result of the radiation. For example, children treated with moderate dose of 131I for thyroid adenomas had a detectable increase in thyroid cancer, but children treated with a much higher dose did not. Likewise, most studies of very-high-dose 131I for treatment of Graves' disease have failed to find any increase in thyroid cancer, even though there is linear increase in thyroid cancer risk with 131I absorption at moderate doses.
In order to determine the composition of the East German representatives in the Bundestag between German reunification and the first post-reunification elections in December 1990, the results of the 1990 Volkskammer election were recounted, using the new states of Germany as constituencies. This was possible since the original election results were declared on the Kreis level, and the states were re-established by simply amalgamating Kreise together. The results in each Kreis forming a state were summed up to determine the statewide result. The recount fixed the number of Volkskammer members from each party who would be co-opted into the Bundestag.
=== Chemical composition === Tear film was described in 1946 by Wolff using a slit lamp to have a three-layered structure: lipid, aqueous, and mucous. Tears are composed of water, salts, antibodies, and lysozymes (antibacterial enzymes). The composition of each layer determines its function. For example, the diverse lipid classes in the tear film lipid layer (TFLL) confer unique physicochemical properties that support roles such as enabling thin film formation and preventing its collapse onto the ocular surface. More recently, Mazyar Yazdani at Oslo University Hospital proposed that the TFLL may also contribute to corneal oxygenation, based on its composition-driven properties. The composition varies among different tear types. The composition of tears caused by an emotional reaction differs from that of tears as a reaction to irritants, such as onion fumes, dust, or allergens. Emotional tears contain higher concentrations of stress hormones such as adrenocorticotropic hormone and leucine enkephalin (a natural pain killer), which suggests that emotional tears play a biological role in balancing stress hormone levels.
The first was neoprene, a synthetic rubber widely used during World War II. The second was an elastic paste that became very strong upon cooling; this would later become nylon. After these discoveries, Carothers' team was made to shift its research from a more pure research approach investigating general polymerization to a more practically focused goal of finding "one chemical combination that would lend itself to industrial applications". It was not until the beginning of 1935 that a polymer called "polymer 6-6" was finally produced. Carothers' coworker, Washington University alumnus Julian W. Hill had used a cold drawing method to produce a polyester in 1930. This cold drawing method was later used by Carothers in 1935 to fully develop nylon. The first example of nylon (nylon 6.6) was produced on February 28, 1935, at DuPont's research facility at the DuPont Experimental Station. It had all the desired properties of elasticity and strength. However, it also required a complex manufacturing process that would become the basis of industrial production in the future. DuPont obtained a patent for the polymer in September 1938, and quickly achieved a monopoly of the fiber. Carothers died 16 months before the announcement of nylon, therefore he was never able to see his success. The name "Nylon" came from the modification of norun (no run) into a unique name that could be used to market the product but was not trademarked.
Sources: en.wikipedia.org
== Further reading == Reineccius, Gary (1998). Sourcebook of Flavors. Berlin: Springer. ISBN 978-0-8342-1307-4. Fennema, O.R., ed. (1985). Food Chemistry (2nd ed.). New York: Marcell Dekker, Inc. pp. 46–50. Bell, L.N.; Labuza, T.P. (2000). Practical Aspects of Moisture Sorption Isotherm Measurement and Use (2nd ed.). Egan, MN: AACC Egan Press.
== History == Electron-capture dissociation (ECD) was developed in 1998 to fragment large proteins for mass spectrometric analysis. Because ECD requires a large amount of near-thermal electrons (<0.2eV), originally it was used exclusively with Fourier transform ion cyclotron resonance mass spectrometry (FTICR), the most expensive form of MS instrumentation. Less costly options such as quadrupole time-of-flight (Q-TOF), quadrupole ion trap (QIT) and linear quadrupole ion trap (QLT) instruments used the more energy-intensive collision-induced dissociation method (CID), resulting in random fragmentation of peptides and proteins. In 2004 Syka and Coon et al. announced the creation of ETD, a dissociation method similar to ECD, but using a low-cost, widely available commercial spectrometer. The first ETD experiments were run on a QLT mass spectrometer with an electrospray ionization (ESI) source.
== Support of women scientists == When Mary Osborn returned to Europe after years in the US, she was surprised to find that European science, technology, engineering, and mathematics (STEM fields) had not opened doors to women as she had experienced in America. She was quoted in an article in Science in 1994 to the effect that women's role in Germany was still "kinder, kuche, kirch" (children, kitchen, church.) In 1992, she had written a protest letter in response to an editorial in Nature that had claimed child care issues were chiefly responsible for the leaky pipeline for women in science, not discrimination. As a woman without children who had experienced no gender discrimination early in her career but had seen differential treatment of men and women in science later, she did not find this argument convincing, and she was appalled to find out that Europe had collected little or no data on rates of success of women in science. Partly because Osborn objected to this situation, the European Commission (EC) appointed her co-chair of a working group to investigate the status of European women scientists and scientists in training and in employment and to prepare a report. The outcome was the European Technology Assessment Network (ETAN) Report on Women in Science, published in 2006, which identified a number of reasons why women dropped out of science and served as a blueprint for Europeans who wished to fix this problem. She noted in 2012 that there was still a leaky pipeline for women scientists in Germany.
Sources: en.wikipedia.org
H2SeO3 + 2 H2S → SeS2 + 3 H2O Selenium disulfide consists of 8-membered rings. It has an approximate composition of SeS2, with individual rings varying in composition, such as Se4S4 and Se2S6. Selenium disulfide has been used in shampoo as an anti-dandruff agent, an inhibitor in polymer chemistry, a glass dye, and a reducing agent in fireworks. Selenium trioxide may be synthesized by dehydrating selenic acid, H2SeO4, which is itself produced by the oxidation of selenium dioxide with hydrogen peroxide:
==== Absorption ==== With oral administration of a single dose, THC is almost completely absorbed by the gastrointestinal tract. However, due to first-pass metabolism in the liver and the high lipid solubility of THC, only about 5 to 20% reaches circulation. Following oral administration, concentrations of THC and its major active metabolite 11-hydroxy-THC (11-OH-THC) peak after 0.5 to 4 hours, with median time to peak of 1.0 to 2.5 hours at different doses. In some cases, peak levels may not occur for as long as 6 hours. Concentrations of THC and 11-hydroxy-THC in the circulation are approximately equal with oral administration. There is a slight increase in dose proportionality in terms of peak and area-under-the-curve levels of THC with increasing oral doses over a range of 2.5 to 10 mg. A high-fat meal delays time to peak concentrations of oral THC by 4 hours on average and increases area-under-the-curve exposure by 2.9-fold, but peak concentrations are not significantly altered. A high-fat meal additionally increases absorption of THC via the lymphatic system and allows it to bypass first-pass metabolism. Consequently, a high-fat meal increases levels of 11-hydroxy-THC by only 25% and most of the increase in bioavailability is due to increased levels of THC. The bioavailability of THC when smoking or inhaling is approximately 25%, with a range of 2% to 56% (although most commonly between 10–35%).
=== Miniature ion trap mass analyzer === Ion traps include quadrupole ion traps or Paul trap, Fourier transform ion cyclotron resonance or Penning trap and newly developed orbitrap. However, Paul trap receives a great focus from researchers for a MMS because of its distinct advantages over other mass analyzers for building MMS. One of the benefits is that ion traps can work at much higher pressures than beam type mass analyzers and can be simplified with different geometry for the ease of fabrication. For example, a miniature quadrupole ion trap mass analyzers, such as cylindrical ion trap, linear ion trap, rectilinear ion trap), can operate at several mTorr in contrast to 10−5 Torr or less for other analyzers and it is able to perform MS/MS in a single device with minimum size of electronics system. Nevertheless, as the size gets smaller, it is hard to maintain the electric field shape and precise configuration and will negatively affect ion motion. The goal is to make the trap smaller without losing ion capacity. Tridion-9 mass spectrometer with toroidal ion trap is designed with a doughnut-shaped volume that can hold up to 400 times more ions. The outstanding result is achieved as the radius is reduced to one-fifth of a conventional laboratory ion trap while maintaining the ion capacity.
Sources: en.wikipedia.org
A responder analysis counts participants who cross a threshold, such as five or ten percent weight loss. It complements average percent change by showing how widely results are distributed. The two measures can diverge when a subset of participants loses a large amount.
Mechanistic measures such as energy expenditure and liver fat change come from small substudies and should be read as preliminary. Long-term clinical outcomes are not yet available. Average weight loss figures are better supported than explanations for how the loss is achieved.
Endpoints reported at different weeks, in different baseline BMI ranges, or under different dose-escalation schedules are not directly comparable. Studies in type 2 diabetes often show smaller weight changes than studies in obesity without diabetes. Reporting the population alongside the number keeps comparisons honest.
It is an investigational peptide that activates three hormone receptors: GIP, GLP-1 and glucagon. It is being studied mainly for obesity and type 2 diabetes, and it is not approved for any clinical use. Published information comes from controlled trials rather than from general practice.