A practical reference on Nuclear receptor: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-08-18 and is reviewed periodically as new material appears.
Laboratory studies have examined GW501516 in cell cultures and rodents for conditions such as dyslipidemia, insulin resistance, and obesity. Some trials in humans were initiated, but development was discontinued after preclinical findings raised concerns about cancer in certain models. Those findings do not prove that the compound causes cancer in people, but they contributed to regulatory caution. Later reviews often describe the evidence as preliminary and insufficient for assessing long-term safety.
In the fitness and bodybuilding literature, cardarine is frequently discussed as an endurance agent or fat-loss compound, although such claims are not supported by robust clinical evidence. Online descriptions often mix animal data, user anecdotes, and marketing language. Researchers who study PPARδ agonists distinguish between receptor activation in controlled experiments and unsupervised use of unverified products. The latter introduces unknown purity, dose, and interactions, making reported experiences difficult to interpret scientifically.
GW501516 acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in transcription of genes related to lipid handling and energy use. Activation of PPARδ can shift skeletal muscle toward greater fatty acid oxidation in animal models, which is one reason it drew interest for metabolic disease and exercise research. The exact downstream effects depend on tissue, species, dose, and duration. Human data are sparse, so many proposed benefits remain hypotheses rather than established clinical outcomes.
Because cardarine is not an approved medicine, no pharmacopeial monograph defines its identity, purity, or storage requirements. Laboratories typically rely on in-house methods and reference standards when testing materials labeled as GW501516. Certificates of analysis may report purity and identity for a specific batch, but their scope varies and they do not guarantee safety or legal status. Independent verification can include high-performance liquid chromatography, mass spectrometry, nuclear magnetic resonance, and elemental analysis. The distinction between research chemical labeling and human use is significant because quality standards and oversight differ.
Cardarine can be detected in biological samples and product materials using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The method separates compounds by chromatography and identifies them by mass-to-charge transitions, allowing low-level detection in urine or blood. Sample preparation often involves enzymatic hydrolysis, solid-phase extraction, or protein precipitation. Certified reference materials and isotope-labeled internal standards improve quantification. Detection windows depend on metabolism, matrix, and assay sensitivity, so no single universal window applies.
Regulatory treatment of cardarine differs by context and jurisdiction. In competitive sport, the World Anti-Doping Agency lists PPARδ agonists, including GW501516, as prohibited at all times. Outside sport, it lacks approval as a prescription medicine in major drug markets, and products sold for human consumption may be treated as unapproved drugs. Some countries also restrict importation or sale through general consumer protection and medicines laws. These classifications affect availability, testing, and legal risk without establishing therapeutic value.
| Property | Value | Notes |
|---|---|---|
| Solubility | Soluble in dimethyl sulfoxide and some organic solvents; practically insoluble in water | Solvent choice affects laboratory handling |
| Typical storage | -20 °C, desiccated, protected from light | Common condition for research samples |
| Analytical method | Liquid chromatography–tandem mass spectrometry (LC-MS/MS) | Used for identification and quantification in biological or product samples |
| Common synonyms | GW501516, GW-501516, GSK-516, Endurobol | Names found in research and anti-doping literature |
| Regulatory status | Unapproved therapeutic; prohibited in competitive sport | Status can vary by country and context |
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
Cardarine is a common name for GW501516, a synthetic compound studied for its effects on lipid and glucose metabolism. It functions as an agonist at peroxisome proliferator-activated receptor delta, or PPARδ, a nuclear receptor that influences gene expression. The molecule is not a steroid, nor is it a selective androgen receptor modulator. It is also known in research and sports literature as GW-501516 and endurobol. Early laboratory work examined its metabolic activity in cell cultures and animal models.
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.
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.
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.
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.
A 1990 book discussing Noriega's administration stated that he had sold thousands of Panamanian passports to the Cuban government for use by its intelligence services. Cuba also obtained hardware imports from Panama that were restricted by the U.S. embargo, while it provided Panama with weapons and military advisers. Libya, as well as some U.S. allies, provided Noriega with funds when the U.S. was seeking to remove him from power.
By the turn of the 20th century, the science of forensics had become largely established in the sphere of criminal investigation. Scientific and surgical investigation was widely employed by the Metropolitan Police during their pursuit of the mysterious Jack the Ripper, who had killed a number of women in the 1880s. This case is a watershed in the application of forensic science. Large teams of policemen conducted house-to-house inquiries throughout Whitechapel. Forensic material was collected and examined. Suspects were identified, traced and either examined more closely or eliminated from the inquiry. Police work follows the same pattern today. Over 2000 people were interviewed, "upwards of 300" people were investigated, and 80 people were detained. The investigation was initially conducted by the Criminal Investigation Department (CID), headed by Detective Inspector Edmund Reid. Later, Detective Inspectors Frederick Abberline, Henry Moore, and Walter Andrews were sent from Central Office at Scotland Yard to assist. Initially, butchers, surgeons and physicians were suspected because of the manner of the mutilations. The alibis of local butchers and slaughterers were investigated, with the result that they were eliminated from the inquiry. Some contemporary figures thought the pattern of the murders indicated that the culprit was a butcher or cattle drover on one of the cattle boats that plied between London and mainland Europe. Whitechapel was close to the London Docks, and usually such boats docked on Thursday or Friday and departed on Saturday or Sunday.
==== Film works and graphic novel ==== Antonov worked on the 2006 film Renaissance directed by Christian Volkman. He then wrote and illustrated the graphic novel The Colony: A Structure Celebrating the Triumphs of Technology, published in 2010. Antonov was also a co-writer and production designer of the 2011 French sci-fi film The Prodigies.
== Scientific research == Amarasate capsules have been clinical tested and demonstrated to reduce hunger and emptiness, to decrease food intake and to increase blood concentrations of appetite suppressing gut peptide hormones CCK, GLP-1 and PYY. Amarasate was developed on the concept that by activating bitter taste receptors (TAS2Rs), in the gastrointestinal tract, it would stimulate the release of these gut-derived hormones and potentially lead to weight loss. Clinical and laboratory research indicates that Amarasate increases GLP-1 and CCK to six times baseline levels, approximately twice the normal post-meal hormone response, within one hour of ingestion. This response mimics the body's natural satiety mechanisms without the use of external GLP-1 agonists. Three small clinical trials have been published, in normal humans:
== Mechanism of action == When a tumor stimulates the growth of new vessels, it is said to have undergone an 'angiogenic switch'. The principal stimulus for this angiogenic switch appears to be oxygen deprivation, although other stimuli such as inflammation, oncogenic mutations and mechanical stress may also play a role. The angiogenic switch leads to tumor expression of pro-angiogenic factors and increased tumor vascularization. Specifically, tumor cells release various pro-angiogenic paracrine factors (including angiogenin, vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and transforming growth factor-β (TGF-β). These stimulate endothelial cell proliferation, migration and invasion resulting in new vascular structures sprouting from nearby blood vessels. Cell adhesion molecules, such as integrins, are critical to the attachment and migration of endothelial cells to the extracellular matrix.
Sources: en.wikipedia.org
=== Standardization === Most of the dyes commonly used in microscopy are available as BSC-certified stains. This means that samples of the manufacturer's batch have been tested by an independent body, the Biological Stain Commission (BSC), and found to meet or exceed certain standards of purity, dye content and performance in staining techniques ensuring more accurately performed experiments and more reliable results. These standards are published in the commission's journal Biotechnic & Histochemistry. Many dyes are inconsistent in composition from one supplier to another. The use of BSC-certified stains eliminates a source of unexpected results. Some vendors sell stains "certified" by themselves rather than by the Biological Stain Commission. Such products may or may not be suitable for diagnostic and other applications.
== Further reading == "Becker Muscular Dystrophy (for Parents)." Edited by Mena T. Scavina, KidsHealth, The Nemours Foundation, Mar. 2018, kidshealth.org/en/parents/becker-md.html. Gaudio, Daniela del; Yang, Yaping; Boggs, Barbara A.; Schmitt, Eric S.; Lee, Jennifer A.; Sahoo, Trilochan; Pham, Hoang T.; Wiszniewska, Joanna; Craig Chinault, A.; Beaudet, Arthur L.; Eng, Christine M. (September 2008). "Molecular diagnosis of Duchenne/Becker muscular dystrophy: enhanced detection of dystrophin gene rearrangements by oligonucleotide array-comparative genomic hybridization". Human Mutation. 29 (9): 1100–1107. doi:10.1002/humu.20841. PMID 18752307. S2CID 21437006. Li, Xihua; Zhao, Lei; Zhou, Shuizhen; Hu, Chaoping; Shi, Yiyun; Shi, Wei; Li, Hui; Liu, Fang; Wu, Bingbing; Wang, Yi (2015). "A comprehensive database of Duchenne and Becker muscular dystrophy patients (0–18 years old) in East China". Orphanet Journal of Rare Diseases. 10 (1): 5. doi:10.1186/s13023-014-0220-7. PMC 4323212. PMID 25612904.
On the basis of the type of human cells/tissues that have been used for engraftment, humanized mouse models for cancer can be classified as patient-derived xenografts or cell line-derived xenografts. PDX models are considered to retain the parental malignancy characteristics at a greater extent and hence these are regarded as the more powerful tool for evaluating the effect of anticancer drugs in pre-clinical studies. Humanized mouse models for studying cancers of various organs have been designed. A mouse model for the study of breast cancer has been generated by the intrahepatic engraftment of SK-BR-3 cells in NSG mice. Similarly, NSG mice intravenously engrafted with patient-derived AML cells, and those engrafted (via subcutaneous, intravenous or intra-pancreatic injections) with patient-derived pancreatic cancer tumors have also been developed for the study of leukemia and pancreatic cancer respectively. Several other humanized rodent models for the study of cancer and cancer immunotherapy have also been reported.
Ants also are quite popular inspiration for many science fiction insectoids, such as the Formics of Ender's Game, the Bugs of Starship Troopers, the giant ants in the films Them! and Empire of the Ants, Marvel Comics' super hero Ant-Man, and ants mutated into super-intelligence in Phase IV. In computer strategy games, ant-based species often benefit from increased production rates due to their single-minded focus, such as the Klackons in the Master of Orion series of games or the ChCht in Deadlock II. These characters are often credited with a hive mind, a common misconception about ant colonies. In the early 1990s, the video game SimAnt, which simulated an ant colony, won the 1992 Codie award for "Best Simulation Program".
Pan, W; Tu, H; Kastin, A (2006). "Differential BBB interactions of three ingestive peptides: Obestatin, ghrelin, and adiponectin". Peptides. 27 (4): 911–6. doi:10.1016/j.peptides.2005.12.014. PMID 16476508. Steckelings, U; Kaschina, E; Unger, T (2005). "The AT2 receptor—A matter of love and hate". Peptides. 26 (8): 1401–9. doi:10.1016/j.peptides.2005.03.010. PMID 16042980. Naleid, A; Grace, M; Cummings, D; Levine, A (2005). "Ghrelin induces feeding in the mesolimbic reward pathway between the ventral tegmental area and the nucleus accumbens". Peptides. 26 (11): 2274–9. doi:10.1016/j.peptides.2005.04.025. PMID 16137788.
Sources: en.wikipedia.org
Some cultures ascribe social and sexual characteristics to female breasts, and may regard bare breasts in public as immodest or indecent. Breasts can represent fertility, femininity, or abundance. Breasts have been featured in ancient and modern sculpture, art, and photography.
==== Europe ==== In 2008, the European Monitoring Centre for Drugs and Drug Addiction noted that although there were some reports of tablets being sold for as little as €1, most countries in Europe then reported typical retail prices in the range of €3 to €9 per tablet, typically containing 25–65 mg of MDMA. By 2014 the EMCDDA reported that the range was more usually between €5 and €10 per tablet, typically containing 57–102 mg of MDMA, although MDMA in powder form was becoming more common.
New revelations were supported by an increase in dinosaur discoveries. Major new dinosaur discoveries have been made by paleontologists working in previously unexplored regions, including India, South America, Madagascar, Antarctica, and most significantly China. Across theropods, sauropodomorphs, and ornithischians, the number of named genera began to increase drastically in the 1990s, with up to 30 new species of dinosaurs named each year by 2008. At least sauropodomorphs experienced a further increase in the number of named species in the 2010s, with an average of 9.3 new species having been named each year between 2009 and 2020. As a consequence, more sauropodomorphs were named between 1990 and 2020 than in all previous years combined. These new localities also led to improvements in overall specimen quality, with new species being increasingly named not on scrappy fossils but on more complete skeletons, sometimes from multiple individuals. Better specimens also led to new species being invalidated less frequently. Asian localities have produced the most complete theropod specimens, while North American localities have produced the most complete sauropodomorph specimens. Prior to the dinosaur renaissance, dinosaurs were mostly classified using the traditional rank-based system of Linnaean taxonomy. The renaissance was also accompanied by the increasingly widespread application of cladistics, a more objective method of classification based on ancestry and shared traits, which has proved tremendously useful in the study of dinosaur systematics and evolution.
==== Tax descriptions ==== The federal personal income tax is progressive, meaning a higher marginal tax rate is applied to higher ranges of income. For example, in 2010 the tax rate that applied to the first $17,000 in taxable income for a couple filing jointly was 10%, while the rate applied to income over $379,150 was 35%. The top marginal tax rate has declined considerably since 1980. For example, the top tax rate was lowered from 70% to 50% in 1980 and reached as low as 28% in 1988. The Bush tax cuts of 2001 and 2003, extended by President Obama in 2010, lowered the top rate from 39.6% to 35%. The American Taxpayer Relief Act of 2012 raised the income tax rates for individuals earning over $400,000 and couples over $450,000. There are numerous exemptions and deductions, that typically result in a range of 35–40% of U.S. households owing no federal income tax. The recession and tax cut stimulus measures increased this to 51% for 2009, versus 38% in 2007. In 2011 it was found that 46% of households paid no federal income tax, however the top 1% contributed about 25% of total taxes collected. In 2014, the top 1% paid approximately 46% of the federal income taxes, excluding payroll taxes. The federal payroll tax (FICA) partially funds Social Security and Medicare. For the Social Security portion, employers and employees each pay 6.2% of the workers gross pay, a total of 12.4%. The Social Security portion is capped at $118,500 for 2015, meaning income above this amount is not subject to the tax.
Sources: en.wikipedia.org
It binds and activates PPARδ, a nuclear receptor that influences gene expression related to fatty acid metabolism and energy balance. This mechanism has been studied mainly in animals and cell models, not established as a safe human therapy.
No. It is not an anabolic-androgenic steroid; it is a synthetic PPARδ agonist. Because it is banned in sport, it is sometimes grouped with doping agents even though its chemical class differs from steroids.
Human data are limited and development was discontinued, so major effects and long-term risks are not well characterized. Some early studies examined metabolic markers, but they do not provide a basis for unsupervised use.
Anti-doping laboratories typically use LC-MS/MS to detect GW501516 and its metabolites in urine. The method is sensitive and can identify the compound at low concentrations. Detection depends on sample timing, metabolism, and the specific assay.