Nuclear receptor is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2025-11-03. Numbers and descriptions here follow the published literature rather than marketing material.
Stability of GW501516 depends on form, temperature, light exposure, and moisture. Solid reference material is typically stored frozen or refrigerated in a desiccator and protected from light. Solutions in organic solvents such as dimethyl sulfoxide are often kept frozen in aliquots to reduce freeze-thaw cycling. Aqueous solubility is low, so aqueous stock solutions can be difficult to prepare without cosolvents. Degradation may appear as changes in chromatographic purity or mass spectral signal. Stability studies are needed to establish shelf life for any specific preparation.
Quality assessment for cardarine samples usually combines identity, purity, and impurity testing. Nuclear magnetic resonance spectroscopy and mass spectrometry can confirm molecular structure, while high-performance liquid chromatography estimates purity. Certificates of analysis from testing laboratories may list these results, but they do not establish safety or legality. In the absence of approved manufacturing, products sold online may contain the wrong compound, variable amounts, or unlisted contaminants. Independent verification is therefore central to analytical work and to interpreting any reported biological activity.
Cardarine is a common name for GW501516, a synthetic compound first described in the 1990s as a selective agonist of the peroxisome proliferator-activated receptor delta. It was studied in preclinical models for metabolic and cardiovascular conditions, but it has not been approved as a medicine in the United States, Europe, or other major jurisdictions. Retail products labeled as cardarine are generally research chemicals or supplements, not pharmaceutical formulations. Because human safety and efficacy data remain limited, regulatory agencies treat it as an unapproved substance rather than a therapeutic product.
Sporting authorities added GW501516 to prohibited lists after it appeared in athlete samples and online markets. The World Anti-Doping Agency classifies it as a hormone and metabolic modulator, and its use can lead to an anti-doping rule violation. Some early laboratory work suggested effects on fatty acid oxidation and endurance-related metabolism in animals, but those findings do not establish safe or effective use in people. Reports of adverse events in humans are scarce and often anecdotal, which complicates risk assessment.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Common for reference-grade material. |
| Solubility | Low in water | Dissolves in DMSO and some organic solvents. |
| Typical storage | -20 °C, desiccated | Protect from light and moisture. |
| Analytical method | LC-MS/MS | Used for trace detection in biological matrices. |
| Purity assessment | HPLC with UV detection | Often combined with NMR and mass spectrometry. |
Early clinical research explored GW501516 for lipid disorders, obesity, and diabetes. Some short-term human studies reported changes in HDL cholesterol, LDL cholesterol, and triglycerides. The development program was discontinued after rodent studies showed dose-dependent tumor formation in multiple tissues, including liver, bladder, stomach, and skin. These findings raised concerns about long-term cancer risk in humans. Because human exposure data are limited, the clinical significance of the rodent tumors remains uncertain.
Literature on cardarine often separates receptor pharmacology from toxicology. Mechanistic papers describe PPARδ activation and gene expression changes, while safety assessments focus on carcinogenicity and species differences. Questions remain about whether rodent tumors arise through PPARδ-dependent or off-target mechanisms. Another open area is how human metabolism and exposure compare with those in animal studies. Analytical methods such as liquid chromatography–mass spectrometry are used to confirm identity in biological and product samples.
GW501516 acts as an agonist at the peroxisome proliferator-activated receptor delta, a nuclear receptor that regulates gene expression. Activation shifts transcription toward genes involved in fatty acid uptake, oxidation, and energy expenditure. The compound does not bind the androgen receptor and therefore differs from anabolic steroids and SARMs. In rodent models, this metabolic shift has been linked to increased running endurance and reduced fat accumulation. The exact downstream pathways in humans remain incompletely characterized.
Cardarine has no approved therapeutic indication and is not marketed as a medicine. The World Anti-Doping Agency lists GW501516 as a prohibited substance at all times, covering both in-competition and out-of-competition periods. National laws vary: some countries treat it as an unapproved drug subject to import controls, while others have specific restrictions on sale for human consumption. It is often sold as a research chemical, a label that does not imply safety or legality. Enforcement actions have targeted online vendors and shipments.
Anti-doping laboratories identify GW501516 and related metabolites using liquid chromatography coupled with tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be analyzed. The method targets the parent compound and phase I and phase II metabolites, which extend the detection window. Because the substance is prohibited at all times, athletes can be tested outside competition. Detection limits and windows depend on the assay, sample type, and individual metabolism.
Cardarine is frequently described as a fat-burning or endurance-enhancing supplement, but these claims exceed the available evidence. The compound is not a hormone, steroid, or selective androgen receptor modulator. Research articles discuss it as a tool compound for studying PPARδ biology, while anti-doping literature focuses on its abuse and detection. Quality of unapproved products is uncertain, and independent analyses have found impurities or incorrect labeling. Open questions include whether human cancer risk resembles that seen in rodents and how often non-athletes use the substance.
Cardarine is a common name for GW501516, an investigational compound developed in the 1990s for metabolic conditions. It acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in lipid and energy metabolism. The compound is frequently mislabeled as a selective androgen receptor modulator, or SARM, but its molecular target is different. GW501516 reached early clinical testing before development was discontinued. It has no approved therapeutic use in any country. The name cardarine is not a formal international nonproprietary name.
Regulatory treatment varies, but cardarine is not approved as a medicine. Sports authorities list GW501516 as a prohibited substance, and it is banned at all times under the World Anti-Doping Agency code. Many countries restrict sales for human consumption, while online vendors market it as a research chemical. Such products may lack purity data, and their actual contents can differ from the label. Purchasing or possessing cardarine may carry legal consequences depending on jurisdiction. The compound is not a dietary supplement ingredient in regulated markets.
Clinical development stopped after rodent studies showed tumors at multiple sites. Whether those findings predict human cancer risk remains an open question, but they led sponsors to discontinue programs. Human safety data are limited to small, short-term studies that were not designed to assess cancer risk. Reported effects in those studies included changes in blood lipids, but the evidence is insufficient for medical use. Long-term consequences of nonmedical use are not well characterized. Questions about dose, duration, and individual susceptibility remain unresolved.
A teenage girl from Greater Manchester is believed to be the first child to be subject to a stalking order after a prolonged campaign of harassment against a family in the area. Two British men are charged with helping Russian intelligence following a suspected arson attack on a Ukrainian business in London. 27 April – Conservative MP and ex-minister Daniel Poulter defects to Labour, saying he has concerns over the NHS and other public services. 28 April – Irish Taoiseach Simon Harris looks at creating legislation to allow the return of asylum seekers to the UK after figures show that 80% of recent asylum seekers arriving in Ireland are people who crossed from Northern Ireland. 29 April – 2024 Scottish government crisis: First Minister, Humza Yousaf, announces he will resign as both leader of the SNP and first minister of Scotland when his successor is chosen. 30 April Brexit: Physical checks begin on meat and dairy products, plants, seeds, and a number of other goods imported from the European Union, which are expected to cost British firms about £330m per year. 2024 Hainault sword attack: A 14-year-old boy is killed and four other people are wounded by a man wielding a sword in Hainault, northeast London. The attacker is arrested and police say the incident is not terror-related. Rwanda asylum plan: Home Office figures suggest that of the 5,700 asylum seekers earmarked for deportation to Rwanda, only 2,143 can immediately be located. BBC News reports that the UK has sent its first failed asylum seeker to Rwanda after he voluntarily agreed to go.
The lungs of birds are relatively small, but are connected to eight or nine air sacs that extend through much of the body, and are in turn connected to air spaces within the bones. On inhalation, air travels through the trachea of a bird into the air sacs. Air then travels continuously from the air sacs at the back, through the lungs, which are relatively fixed in size, to the air sacs at the front. From here, the air is exhaled. These fixed size lungs are called "circulatory lungs", as distinct from the "bellows-type lungs" found in most other animals. The lungs of birds contain millions of tiny parallel passages called parabronchi. Small sacs called atria radiate from the walls of the tiny passages; these, like the alveoli in other lungs, are the site of gas exchange by simple diffusion. The blood flow around the parabronchi and their atria forms a cross-current process of gas exchange (see diagram on the right). The air sacs, which hold air, do not contribute much to gas exchange, despite being thin-walled, as they are poorly vascularised. The air sacs expand and contract due to changes in the volume in the thorax and abdomen. This volume change is caused by the movement of the sternum and ribs and this movement is often synchronised with movement of the flight muscles. Parabronchi in which the air flow is unidirectional are called paleopulmonic parabronchi and are found in all birds. Some birds, however, have, in addition, a lung structure where the air flow in the parabronchi is bidirectional. These are termed neopulmonic parabronchi.
=== International normalized ratio === The result (in seconds) for a prothrombin time performed on a normal individual will vary according to the type of analytical system employed. This is due to the variations between different types and batches of manufacturer's tissue factor used in the reagent to perform the test. The INR was devised to standardize the results. Each manufacturer assigns an ISI value (International Sensitivity Index) for any tissue factor they manufacture. The ISI value indicates how a particular batch of tissue factor compares to an international reference tissue factor. The ISI is usually between 0.94 and 1.4 for more sensitive and 2.0–3.0 for less sensitive thromboplastins. The INR is the ratio of a patient's prothrombin time to a normal (control) sample, raised to the power of the ISI value for the analytical system being used.
Sources: en.wikipedia.org
A rotary lathe in which the wood is turned against a very sharp blade and peeled off in one continuous or semi-continuous roll. Rotary-cut veneer is mainly used for plywood, as the appearance is not desirable because the veneer is cut concentric to the growth rings. A slicing machine in which the flitch or piece of log is raised and lowered against the blade and slices of the log are made. This yields veneer that looks like sawn pieces of wood, cut across the growth rings; such veneer is referred to as "crown cut". A half-round lathe in which the log or piece of log can be turned and moved in such a way as to expose the most interesting parts of the grain, creating a more textured feel and appearance; such veneer is commonly referred to as "rift cut". Each slicing process gives a very distinctive type of grain, depending upon the tree species. In any of the veneer-slicing methods, when the veneer is sliced, a distortion of the grain occurs. As it hits the wood, the knife blade creates a "loose" side where the cells have been opened up by the blade, and a "tight" side. Veneers are cut as thin as 0.64 mm (1⁄40 in). Depending on the cutting process used by the veneer manufacturer, very little wood is wasted by the saw blade thickness, known as the saw kerf. Some manufacturers use a very wide knife to slice off the thin veneer pieces. In this process, none of the wood is wasted. The slices of veneer are always kept in the order in which they are cut from the log and are often sold this way. Historically, veneers were also sawn in approximately 3 mm (1⁄8 in) thick layers.
S100 calcium-binding protein A12 (S100A12) is a protein that in humans is encoded by the S100A12 gene. Human S100A12, also known as calgranulin C, was first described in 1995. The protein encoded by this gene is a member of the S100 family of proteins containing 2 EF-hand calcium-binding motifs.
=== Locations === Stumptown operates five cafes in Portland. They are located on SE 45th & Division St., SE 34th & Belmont, downtown at SW 3rd & Ash St., inside the Ace Hotel at 1022 SW Stark Street, and at the Portland International Airport. The company also owns a roasting facility and a retail annex inside their headquarters at 100 SE Salmon St. The original location on SE Division was previously a hair salon called "The Hair Bender," whose name Stumptown adopted for one of their signature espresso blends. In November 2007, Stumptown opened two cafes in Seattle. In September 2009, the company also launched a cafe in New York's Ace Hotel. A temporary "pop-up" location appeared in Amsterdam's De Pijp neighborhood in May 2010. Opened by Sorenson, he claimed it was never intended to be permanent and closed its doors that same year. In 2013, Stumptown opened a second New York City café and a café/roaster in Los Angeles. Additional cafes have also opened in Chicago and New Orleans. Stumptown opened their third New York cafe in a historic Brooklyn firehouse in the summer of 2018. A location at the Portland International Airport opened in 2024.
=== Society and culture === The use of sovereign power, codes of conduct, religious and cultural practices and other dynamic processes in a society can be described as a part of an evolved homeostatic system of regularizing life and maintaining an overall equilibrium that protects the security of the whole from internal and external imbalances or dangers. Healthy civic cultures can be said to have achieved an optimal homeostatic balance between multiple contradictory concerns such as in the tension between respect for individual rights and concern for the public good, or that between governmental effectiveness and responsiveness to the interests of citizens.
Sources: en.wikipedia.org
== Gene == GRP is located on chromosome 18q21. PreproGRP (the unprocessed form of GRP) is encoded in three exons separated by two introns. Alternative splicing results in multiple transcript variants encoding different isoforms.
Multiple theories were proposed for why earlier research was able to produce Form 2 from "pure" ingredients, ranging from the possibility that the early researchers were unintentionally working with impure materials to the possibility that seed crystals of Form 1 had become more common in the atmosphere of laboratories since the 1970s.
=== 2000 census === As of the 2000 United States census there were 7,746 people, 2,630 households, and 2,161 families residing in the borough. The population density was 3,625.9 inhabitants per square mile (1,400.0/km2). There were 2,702 housing units at an average density of 1,264.8 per square mile (488.3/km2). The racial makeup of the borough was 78.05% White, 0.92% African American, 0.04% Native American, 18.64% Asian, 0.65% from other races, and 1.70% from two or more races. Hispanic or Latino of any race were 3.99% of the population. There were 2,630 households, out of which 40.6% had children under the age of 18 living with them, 71.1% were married couples living together, 8.5% had a female householder with no husband present, and 17.8% were non-families. 15.9% of all households were made up of individuals, and 9.7% had someone living alone who was 65 years of age or older. The average household size was 2.91 and the average family size was 3.26. In the borough the age distribution of the population shows 26.3% under the age of 18, 4.7% from 18 to 24, 26.4% from 25 to 44, 25.7% from 45 to 64, and 16.9% who were 65 years of age or older. The median age was 41 years. For every 100 females, there were 92.7 males. For every 100 females age 18 and over, there were 88.2 males. The median income for a household in the borough was $84,692, and the median income for a family was $96,245. Males had a median income of $61,194 versus $38,990 for females. The per capita income for the borough was $41,573.
Sources: en.wikipedia.org
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.
Reference material is usually kept cold, dry, and protected from light. Frozen aliquots reduce repeated freeze-thaw cycles.
No approved pharmaceutical product exists, so manufacturing and quality controls are not standardized. Products may contain different compounds or impurities.
No. Major drug regulators have not approved GW501516 for treating any medical condition. Products sold as cardarine are typically unapproved research chemicals or supplements, so their contents and safety are not assured.