anti-doping comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-07-13. Numbers and descriptions here follow the published literature rather than marketing material.
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 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.
Published human data are sparse and mostly come from early-phase trials. Those studies examined short-term changes in lipids, glucose, and exercise capacity, but they were not large enough to establish efficacy or long-term safety. Some animal experiments reported increased running endurance, yet such findings do not prove a performance benefit in people. Anti-doping laboratories detect GW501516 and its metabolites in urine or blood using liquid chromatography-tandem mass spectrometry. Detection windows depend on dose, sample type, and individual metabolism. The method is sensitive enough to identify trace residues in tested samples.
Laboratory handling focuses on identity, purity, and stability. Reference standards are typically stored cold and dry, protected from light, because solutions can degrade over time. Analytical checks may use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Impurities and related substances can be separated chromatographically and compared with a known standard. Because cardarine is not an approved drug, compendial monographs are absent, and laboratories often rely on in-house methods. Reported purity varies among unregulated products and should not be assumed from a label.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Prohibited in sport; not approved as medicine | Listed by WADA at all times. |
| Common synonyms | GW501516, GW-501516, endurobol | Cardarine is a colloquial name. |
| Typical analytical method | LC-MS/MS | Detects parent compound and metabolites. |
| Common test matrix | Urine | Blood and dried blood spots also possible. |
| Legal classification | Varies by country | Often treated as unapproved drug or research chemical. |
The enzyme uses molecular oxygen and reduced nicotinamide adenine dinucleotide phosphate (NADPH) to insert a hydroxy group into a specific position in one of the benzene rings of the starting material. It is a cytochrome P450 protein containing heme which acts as an oxidoreductase. The systematic name of this enzyme class is flavonoid,NADPH:oxygen oxidoreductase (3′-hydroxylating). Other names in common use include flavonoid 3′-hydroxylase, flavonoid 3-hydroxylase (erroneous), NADPH:flavonoid-3′-hydroxylase, and flavonoid 3-monooxygenase (erroneous). In palnts including Matthiola incana from which it was first characterised, it is part of the pathway to anthocyanins.
According to the American Heart Association (AHA) a chest x-ray should not be used to diagnose or assess for aortic dissections. The AHA states that chest x-rays are not adequately sensitive nor specific to accurately diagnose aortic dissections. However, certain findings on a chest x-ray may suggest an aortic dissection. These findings include: widening of the mediastinum, disruption of the normal contour of the aortic knob, the calcium sign (a separation of more than 5 mm of the calcified intimal plaque layer from the aortic wall), a "double density" seen in the aorta, and deviation of the trachea to the right.
In addition to the myoglobinuria, two other mechanisms contribute to kidney impairment: low blood pressure leads to constriction of the blood vessels and therefore a relative lack of blood flow to the kidney, and finally, uric acid may form crystals in the tubules of the kidneys, causing obstruction. Together, these processes lead to acute tubular necrosis, the destruction of the cells of the tubules. Glomerular filtration rate falls, and the kidney is unable to perform its normal excretory functions. This disrupts electrolyte regulation, leading to a further rise in potassium levels, and interferes with vitamin D processing, further worsening the low calcium levels.
== Drafting == Declassification of British government archives has allowed scholars to piece together the choreography of the drafting of the declaration; in his widely cited 1961 book, Leonard Stein published four previous drafts of the declaration. The drafting began with Weizmann's guidance to the Zionist drafting team on its objectives in a letter dated 20 June 1917, one day following his meeting with Rothschild and Balfour. He proposed that the declaration from the British government should state: "its conviction, its desire or its intention to support Zionist aims for the creation of a Jewish national home in Palestine; no reference must be made I think to the question of the Suzerain Power because that would land the British into difficulties with the French; it must be a Zionist declaration." A month after the receipt of the much-reduced 12 July draft from Rothschild, Balfour proposed a number of mainly technical amendments. The two subsequent drafts included much more substantial amendments: the first in a late August draft by Lord Milner – one of the original five members of Lloyd George's War Cabinet as a minister without portfolio – which reduced the geographic scope from all of Palestine to "in Palestine", and the second from Milner and Amery in early October, which added the two "safeguard clauses".
Sources: en.wikipedia.org
=== Common properties === The various ribosomes share a core structure, which is quite similar despite the large differences in size. Much of the RNA is highly organized into various tertiary structural motifs, for example pseudoknots that exhibit coaxial stacking. The extra RNA in the larger ribosomes is in several long continuous insertions, such that they form loops out of the core structure without disrupting or changing it. All of the catalytic activity of the ribosome is carried out by the RNA; the proteins reside on the surface and seem to stabilize the structure.
=== Effects === A spasm may lead to muscle strains or tears in tendons and ligaments if the force of the spasm exceeds the tensile strength of the underlying connective tissue. This can occur with a particularly strong spasm or with weakened connective tissue.
=== Visual effects === Zoic Studios provided visual effects for the series. According to Johns, Stargirl was the first Warner Bros. Television series to use previsualization (a process most commonly used by feature films) for their effects scenes. Previsualization was handled by The Third Floor, Inc. Johns brought his experience working on the films Wonder Woman (2017), Aquaman (2018), and Shazam! (2019) to help the series have visuals not "seen in superhero shows before".
In 1992, Hooters sponsored NASCAR driver Alan Kulwicki as he won the Winston Cup Championship, beating Bill Elliott by ten points, the closest margin in NASCAR prior to The Chase era. On April 1, 1993, Kulwicki, along with several others including Hooters Chairman Bob Brooks's son Mark, were killed in a plane crash near Bristol, Tennessee. They were flying back to the track for Sunday's race after making a sponsor appearance at a Hooters in Knoxville, Tennessee. Hooters remained in the sport, sponsoring drivers like Loy Allen Jr., Rick Mast and Brett Bodine before ending their involvement in 2003. The restaurant returned to NASCAR in 2007 to sponsor a Craftsman Truck Series team led by Jason White, Derrike Cope and Brad Keselowski. Six years later, Hooters sponsored Nationwide Series driver Nelson Piquet Jr.'s car. For the 2016 Bojangles' Southern 500 at Darlington Raceway, Hooters made a comeback in the Cup Series with a one-off paint scheme for Greg Biffle. Hooters most recently sponsored the No. 9 of Chase Elliott from 2017 to 2024. Hooters has sponsored the Major League Eating-sanctioned "Hooters Worldwide Wing Eating Championship" since 2012. Hooters has also licensed its name for the Hooters Road Trip PlayStation racing game. Furthermore, Hooters licensed the Hooters Calendar for Hooters Calendar Girl, a mobile wallpaper application, and Hooters Calendar Girl Tubin', a mobile game, both by Oasys Mobile. It was also one of several real world brands that appeared in the 2011 video game Homefront.
==== Purity ==== One published study that analysed samples of mephedrone bought using the internet in the UK in 2010 found it was racemic (a mixture of both stereoisomers) and of high purity. An unpublished study of six samples also ordered off the internet in the UK in 2010 found they contained very few organic impurities. Four products sold in Irish head shops were tested in 2010 and were found to contain between 82% and 14% mephedrone, with some products containing benzocaine and caffeine.
Sources: en.wikipedia.org
Legal status varies by country. It is not approved as a medicine, and it is prohibited in sport. Some jurisdictions restrict import, sale, or possession.
Laboratories use liquid chromatography-tandem mass spectrometry to detect GW501516 and its metabolites. Urine is commonly tested, and testing can occur in and out of competition.
No, cardarine is not a SARM. It is a PPARδ agonist, which acts on a different receptor. The two classes are often confused in online discussions.
Anti-doping and clinical laboratories commonly use liquid chromatography-tandem mass spectrometry. The method can identify GW501516 and its metabolites in urine or blood. Detection depends on sample timing and the amount present.