If you have been reading about Nuclear receptor and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-11-08. Where a claim depends on a specific study, the study is described rather than over-claimed.
Legal status varies by country. In some places, cardarine is controlled under medicines or psychoactive substances laws; in others, it may be sold with minimal oversight as a research chemical. Customs agencies have intercepted shipments, and several national health agencies have issued warnings about products marketed for bodybuilding or performance enhancement. The lack of a standardized pharmaceutical supply means identity, purity, and contamination levels can differ widely between samples. These factors make cardarine a regulatory and public health concern rather than a conventional prescription drug.
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.
A common misconception is that cardarine has been proven safe for human use. In reality, human clinical data are limited, and long-term animal studies have raised concerns about cancer. Another misconception is that it is a supplement or vitamin-like compound. It is a synthetic research chemical with no approved medical indication. Scientific discussion often focuses on its mechanism and detection rather than therapeutic use. Regulatory and anti-doping literature treats it primarily as a prohibited substance.
Cardarine is explicitly prohibited by the World Anti-Doping Agency under the class of PPARδ agonists. Its presence in urine or blood samples can be detected using mass spectrometry-based methods, often liquid chromatography-tandem mass spectrometry. Athletes who test positive may face sanctions, including bans from competition. The compound is also regulated as a prescription-only or unapproved drug in many countries. Enforcement varies by jurisdiction, and some regions treat it as a controlled substance. Online sales may occur despite these restrictions, creating quality and legal risks.
Laboratory detection of cardarine typically involves sample preparation followed by chromatographic separation and mass spectrometric identification. Urine is the most common matrix for anti-doping tests, though blood and hair have also been explored. Methods can target the parent compound or its metabolites, depending on the expected window of detection. Reference standards are required for accurate quantification. Matrix effects and dilution can influence results, so laboratories use internal standards and validation protocols. The exact detection window varies with dose, route, and individual metabolism.
| Property | Value | Notes |
|---|---|---|
| IUPAC name | {4-[({4-methyl-2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-5-yl}methyl)sulfanyl]phenoxy}acetic acid | Systematic name for GW501516 |
| CAS Registry Number | 317318-70-0 | Unique identifier for the parent compound |
| Molecular formula | C21H18F3NO3S2 | Includes carbon, hydrogen, fluorine, nitrogen, oxygen, and sulfur |
| Molecular weight | 453.5 g/mol | Approximate value for the neutral form |
| Appearance | White to off-white powder | Typical description for purified laboratory material |
Anti-doping laboratories detect GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be used in some programs. Detection depends on factors such as dose, timing, metabolism, and the sensitivity of the assay. Published methods describe limits of detection in the low nanogram per milliliter range for related compounds. Exact detection windows are not fixed for all situations and remain an area of ongoing study.
Products sold as cardarine have been found to contain incorrect compounds, variable amounts, or no active ingredient at all. Independent testing is required to verify identity and purity. Common analytical approaches include high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance for structural confirmation. These methods can distinguish GW501516 from related PPAR agonists and from unrelated steroids. For regulators and researchers, such verification is central to interpreting both biological results and adverse event reports.
Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.
Human trials of GW501516 were small and short in duration. They examined lipid levels, glucose handling, and other metabolic markers, but the programs were halted after the animal cancer findings. No approved therapeutic product exists, and published human data are insufficient for establishing long-term safety. Reports of use for athletic performance come mainly from non-clinical settings and cannot be verified through controlled trials. Independent testing of products sold as cardarine has found inconsistent purity and labeling.
Laboratory studies indicate that GW501516 activates PPARδ, a nuclear receptor involved in fatty acid oxidation and energy metabolism. In rodent experiments, treated animals often showed increased endurance and reduced fat mass. These effects were observed under controlled conditions and do not establish safe or effective use in humans. The exact dose-response relationship in humans remains poorly characterized. Species differences in metabolism can affect how results translate across animals and people.
PPARδ is a nuclear receptor that regulates gene expression related to fatty acid oxidation, glucose homeostasis, and mitochondrial function. GW501516 binds to this receptor with high affinity and activates downstream signaling in skeletal muscle and other tissues. Animal studies reported increased endurance and altered fuel preference, but human data remain limited and inconsistent. The precise relationship between receptor activation and observed physiological changes is still an area of active investigation. Researchers have also examined whether the compound affects inflammation or cell proliferation. No approved therapeutic indication exists for cardarine.
In laboratory settings, cardarine is studied as a tool compound for probing PPARδ biology. Published experiments often use cell cultures, rodent models, or isolated tissues. Some investigations focus on metabolic effects, while others assess potential risks such as carcinogenicity observed in long-term animal studies. Because human trials are sparse, most knowledge comes from preclinical work and adverse event reports. Scientific literature frequently notes the gap between animal findings and human outcomes. The compound is not a dietary supplement and is not intended for human consumption.
== Scientific evaluation == The German Institute for International and Security Affairs (SWP) recognized a rise in the Shiite Badr organization since 2014 under the leadership of its Secretary General Hadi al-Amiri. In 2017, SWP wrote that the Badr organization is one of "the most important actors in Iraqi politics". It has become the most important instrument of Iranian politics in Iraq. Its aim is "to exert the greatest possible influence on the central government in Baghdad and at the same time to build the strongest possible Shiite militias that are dependent on Iran". The foundation compared the role of the organization with that of Hezbollah in Lebanon.
The manner in which the company licenses its franchisees varies depending on the region, with some regional franchises, known as master franchises, responsible for selling franchise sub-licenses on the company's behalf. Burger King's relationship with its franchises has not always been harmonious. Occasional spats between the two have caused numerous issues; in several instances, the relations between the company and its licensees have degenerated into precedent-setting court cases. Burger King's Australian franchise Hungry Jack's is the only franchise to operate under a different name due to a trademark dispute with a similarly named restaurant in Adelaide, South Australia, and a series of legal cases between the two.
=== Bladed weapons === No. 4 Bayonet - Used with the Lee-Enfield No. 4 No. 5 Mk 1 Bayonet - Used with the Sterling submachine gun No. 9 Mk 1 Bayonet - Used with the Lee-Enfield No. 4 L1A1-A4 Bayonet - Used with the L1A1 SLR L3A1 Bayonet - Used with the L85A1 Collins machete Golok machete
== Structural studies == As of late 2007, 8 structures have been solved for this class of enzymes, with PDB accession codes PDB: 1VKN, PDB: 2CVO, PDB: 2G17, PDB: 2I3A, PDB: 2I3G, PDB: 2NQT, PDB: 2OZP, and PDB: 2Q49.
Macrophages can be stimulated by T cell secretion of interferon. After this activation, macrophages are able to express MHC class II and co-stimulatory molecules, including the B7 complex and can present phagocytosed peptide fragments to helper T cells. Activation can assist pathogen-infected macrophages in clearing the infection. Deriving from monocytes, a type of white blood cell, they will circulate in the blood and enter affected sites and differentiate from monocytes to macrophages. At the affected site, the macrophage surrounds the site of infection or tissue damage with its membrane in a mechanism called phagocytosis.
Sources: en.wikipedia.org
While agreeing with the editorial's conclusion, a reply noted that its finding in the negative was guaranteed, given that "global dose estimates or results of mathematical modelling are too inaccurate to be used as dose values for an individual veteran", and that, as of April 2001, no practical method of measuring the expected small doses that each individual veteran would receive had been suggested. The author of the reply, a radiation scientist, went on to suggest a method that had been used several times before, including after the 1986 Chernobyl accident. Despite the widespread use of DU in the Iraq War, at least a year after the conflict began, testing of UK troops was still only in the discussion phase. The Royal Society Working Group on the Health Hazards of Depleted Uranium Munitions (RSDUWG) concluded in 2002 that there were "very low" health risks associated with the use of depleted uranium, though it also ventured that, "[i]n extreme conditions and under worst-case assumptions" lung and kidney damage could occur, and that in "worst-case scenarios high local levels of uranium could occur in food or water that could have adverse effects on the kidney". In 2003, the Royal Society issued another urgent call to investigate the actual health and environmental impact of depleted uranium. The same year, a cohort study of Gulf War veterans found no elevated risks of cancer generally, nor of any specific cancers in particular, though recommended follow up studies.
=== Digestive === The apelin receptor is expressed in several cell types of the gastro-intestinal tract : stomach enterochromaffine-like cells; unknown cells of endocrine pancreas, colon epithelial cells. In stomach, activation of receptors on enterochromaffine-like cells by apelin secreted by parietal cells can inhibit histamine release by enterochromaffine-like cells, which in turn decreases acid secretion by parietal cells. In pancreas, apelin inhibits the insulin secretion induced by glucose. This inhibition reveals the functional interdependency between apelin signalling and insulin signalling observed at the adipocyte level where insulin stimulate apelin production. Recently, receptor expression was also detected in skeletic muscle cells. Its activation is involved in glucose uptake and participates in the control of glucose blood levels glycemia.
In the example of lysosomal lipase, the enzyme is confined within an organelle called the lysosome. Other lipase enzymes, such as pancreatic lipases, are secreted into extracellular spaces where they serve to process dietary lipids into more simple forms that can be more easily absorbed and transported throughout the body. Fungi and bacteria may secrete lipases to facilitate nutrient absorption from the external medium (or in examples of pathogenic microbes, to promote invasion of a new host). Certain wasp and bee venoms contain phospholipases that enhance the effects of injury and inflammation delivered by a sting. As biological membranes are integral to living cells and are largely composed of phospholipids, lipases play important roles in cell biology. Malassezia globosa, a fungus thought to be the cause of human dandruff, uses lipase to break down sebum into oleic acid and increase skin cell production, causing dandruff. Genes encoding lipases are even present in certain viruses. Some lipases are expressed and secreted by pathogenic organisms during an infection. In particular, Candida albicans has many lipases, possibly reflecting broad-lipolytic activity, which may contribute to the persistence and virulence of C. albicans in human tissue.
== Other animals == In fish, there is a single membrane known as the primitive meninx. Amphibians and reptiles have two meninges, and birds and mammals have three. Mammals (as higher vertebrates) retain the dura mater, and the secondary meninx divides into the arachnoid and pia mater.
Sources: en.wikipedia.org
== Life habits == This nudibranch feeds on hydroids and other marine organisms such as ascidians and sea anemones. It sometimes attacks other nudibranchs, and will eat smaller specimens of its own species. It is host to the ectoparasites Halicyclops thysanotus Wilson C.B., 1935 and Hemicyclops thysanotus Wilson C.B., 1935.
== Derivation by dimensional analysis == Away from the ends of the pipe, the characteristics of the flow are independent of the position along the pipe. The key quantities are then the pressure drop along the pipe per unit length, Δp/L, and the volumetric flow rate. The flow rate can be converted to a mean flow velocity V by dividing by the wetted area of the flow (which equals the cross-sectional area of the pipe if the pipe is full of fluid). Pressure has dimensions of energy per unit volume, therefore the pressure drop between two points must be proportional to the dynamic pressure q. We also know that pressure must be proportional to the length of the pipe between the two points L as the pressure drop per unit length is a constant. To turn the relationship into a proportionality coefficient of dimensionless quantity, we can divide by the hydraulic diameter of the pipe, D, which is also constant along the pipe. Therefore,
Canada's mixed-market economy is highly developed, ranking as the world's ninth-largest by nominal GDP as of 2023, at approximately US$2.221 trillion. The country is one of the world's largest trading nations, with a highly globalized economy. In 2021, Canadian trade in goods and services reached $2.016 trillion. Canada's exports totalled over $637 billion, while its imported goods were worth over $631 billion, of which approximately $391 billion originated from the United States. The Toronto Stock Exchange is the ninth-largest stock exchange in the world by market capitalization, listing over 1,500 companies with a combined market capitalization of over US$2 trillion. The Bank of Canada is the central bank of the country. The minister of finance and minister of innovation, science, and industry use data from Statistics Canada to enable financial planning and develop economic policy. Canada has a strong cooperative banking sector, with the world's highest per-capita membership in credit unions. Canada "is widely regarded as among the least corrupt countries of the world", with a relatively low level of income disparity. The country's average household disposable income per capita is "well above" the OECD average. In 2024, Canada had the second-largest foreign direct investment stock-to-GDP ratio among G20 countries and the lowest net debt of G7 members. Notwithstanding, Canada ranks among the lowest of the most developed countries for income growth and housing affordability.
cocoa coffee guarana (caffeine in guarana is sometimes called guaranine) kola tea (caffeine in tea is sometimes called theine) – also contains theanine yerba mate (caffeine in yerba mate is sometimes called mateine) Most known psychoactive plants:
=== Early life and career abroad === Zervas was born in 1902 in the rural town of Megalopolis in Arcadia, southern Greece. He was the first of 7 children of lawyer and parliamentarian Theodoros Zervas with Vasiliki Zerva (née Gyftaki). After finishing secondary education at the local Gymnasion of Kalamata in 1918, he went to study Chemistry at the University of Athens. Before finishing his studies there, he moved to Berlin in 1921 where he graduated with a degree in chemistry from the University of Berlin in 1924. Under the supervision of Max Bergmann, he finished his doctoral thesis on the reactions of amino acids with aldehydes and was awarded his Dr. rer. nat. from the University of Berlin in 1926. He proceeded to work with Bergmann in the Kaiser Wilhelm Institute for Leather Research in Dresden, of which Bergmann was the founder and director. From 1926 to 1929 Zervas was a research associate and eventually rose to head of the organic chemistry division and vice-director of the institute (1929–1934). It was at this period that the two men developed the Bergmann-Zervas oligopeptide synthesis which brought them international fame within academic circles. Zervas, by that point a close personal friend of Bergmann, decided to follow the latter to the US in 1934 after Bergmann emigrated from Nazi Germany in 1933 under pressure due to his Jewish origin. In New York, Zervas spent 3 years as lecturer and researcher at the Rockefeller Institute for Medical Research. In 1930, he married Hildegard Lange, and they remained together until his death.
Sources: en.wikipedia.org
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.
It is prohibited by the World Anti-Doping Agency as a hormone and metabolic modulator. Athletes who test positive for GW501516 can face sanctions, including suspensions and loss of results.
Cardarine is a common or trade-style name, while GW501516 is the research code for the same chemical entity. Some sources also use Endurobol or GSK-516. The names refer to the same compound, not distinct drugs.
Yes, WADA prohibits cardarine as a PPARδ agonist. It appears on the prohibited list and can be detected in urine or blood. Athletes using it risk sanctions.