Everything below concerns prohibited list. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-11-08. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| 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 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.
Published literature on cardarine includes in vitro assays, rodent experiments, and a small number of human studies. Reports describe effects on exercise capacity and lipid metabolism in animals, while human evidence is sparse. Many online descriptions present the compound as a proven endurance aid, a claim not supported by regulatory approval or large clinical trials. Analytical studies focus on identifying the parent compound and its metabolites in biological samples. Important uncertainties include species differences, dose-response relationships, and the relevance of rodent tumor findings to humans.
Cardarine is the common name for GW501516, a synthetic compound studied as a peroxisome proliferator-activated receptor delta agonist. Researchers developed it to explore treatments for lipid disorders and metabolic conditions. It is not an approved medicine in any country. Early clinical work examined changes in HDL cholesterol and triglycerides, but development was discontinued after animal studies raised concerns about cancer. The compound remains available as a research chemical and appears in discussions of performance enhancement.
Anti-doping laboratories identify GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the usual matrix, and detection can occur after the parent compound has cleared from blood. The exact detection window depends on dose, formulation, individual metabolism, and assay sensitivity. Because the compound is prohibited at all times, athletes are subject to testing in and out of competition. Analytical methods continue to improve as new metabolites and designer analogs are characterized.
GW501516 acts as a ligand for PPAR delta, a nuclear receptor that regulates transcription of genes involved in fatty acid oxidation and energy use. Activation of this receptor in skeletal muscle shifts metabolism toward fat burning in animal models. The compound does not burn fat directly; it changes gene expression over hours to days. Researchers study it to understand metabolic flexibility and exercise adaptation. Effects observed in rodents are not automatically expected in humans.
Analytical laboratories typically identify cardarine and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is a common matrix in anti-doping testing, while blood and tissue may be used in research settings. Detection windows depend on the assay, the sample matrix, and the compound's metabolism. Because cardarine is extensively metabolized, laboratories often target specific metabolites to improve sensitivity and confirmation. Reference standards are required for reliable quantification. Method validation includes checks for selectivity, linearity, and carryover.
A persistent misconception is that cardarine is a fat-burning drug or a safe alternative to anabolic steroids. No approved therapeutic product exists, and human safety data are limited. The tumor findings in rodents remain a central concern in scientific reviews. Products sold online may contain inaccurate labels, impurities, or different compounds entirely, which complicates any assessment of effects. Independent testing of such products has reported frequent mislabeling. For these reasons, discussions in the literature emphasize risks and unknowns rather than benefits.
Cardarine is not approved for human therapeutic use in any major jurisdiction. It appears on the World Anti-Doping Agency Prohibited List as a PPARδ agonist within the hormone and metabolic modulators category. Sports organizations test for it because it has been detected in athlete samples and seized products. Regulatory actions against marketed research chemical versions have occurred in several countries, though enforcement varies. Availability through unregulated channels complicates oversight.
=== European Union === In August 2021, Foreign Minister Béjar announced Peru's withdrawal, without officially carrying it out, from the Lima Group and support for the International Contact Group of the European Union for a negotiated solution between the regime of Nicolás Maduro and the opposition regarding the Venezuelan crisis. In addition, Béjar announced his intention, as foreign minister, to reconstitute the UNASUR and strengthen the CELAC, although this was not officially carried out.In September 2021, the Peruvian government signed the "Development Objectives Grant Agreement" with the United States Agency for International Development (USAID) to receive 321 million dollars through 2026. The agreement was signed between Foreign Minister Maúrtua and Jene Thomas, USAID mission director, in the presence of U.S. ambassador Lisa Kenna, who before joining the diplomatic service had been an agent of the CIA. During that same month, the Peruvian government signed the United Nations Sustainable Development Cooperation Framework in Peru 2022-2026 for 180 million dollars, with the framework's preparation led by the resident coordinator of the United Nations System (UNS) in the country to "contribute to the efforts of the Government of Peru in fulfilling the 2030 Agenda and the Sustainable Development Goals, as well as the national development priorities with which this roadmap aligns", also establishing "the general guidelines for developing joint work plans between the Government of Peru and twenty-two AFPs [UN Agencies, Funds and Programmes]" over the following five years.
Alfred Otto Carl Nier (May 28, 1911 – May 16, 1994) was an American physicist who pioneered the development of mass spectrometry. He was the first to use mass spectrometry to isolate uranium-235 which was used to demonstrate that 235U could undergo fission and developed the sector mass spectrometer configuration now known as Nier-Johnson geometry.
== Contraindications == Dihydroergotamine is contraindicated with potent CYP3A4 inhibitors, like macrolide antibiotics. Contraindications for dihydroergotamine include: pregnancy, kidney failure or liver failure, coronary, cerebral, and peripheral vascular disease, hypersensitivity reactions, sepsis, and uncontrolled hypertension.
== Deaths == 18 January – Sir David Cox, English statistician (b. 1924) 15 March – Eugene Parker, American solar and plasma physicist (b. 1927) 20 March – Wen Shengchang, Chinese oceanographer and member of the Chinese Academy of Sciences (b. 1921) 23 March – Arthur Riggs, American geneticist (b. 1939) 27 March – Martin Pope, American physical scientist (b. 1918) 27 March – James Vaupel, American demographer and aging researcher (b. 1945) 29 March – Paul Benioff, American physicist of quantum computing (b. 1930) 30 March – Kenneth Walters, British mathematician and rheologist (b. 1934) 1 April – Gerhard J. Woeginger, Austrian mathematician. 5 April – Sidney Altman, Canadian-American molecular biologist, Nobel Prize laureate (1989). 5 April – Bjarni Tryggvason, Icelandic-born Canadian astronaut (STS-85). 5 April – Eelco Visser, Dutch computer scientist. 5 April – Leslie Young, New Zealand economist. 1 May – Ray Freeman, British chemist. 1 May – Dominique Lecourt, French philosopher. 2 May – Joseph Raz, Israeli philosopher. 4 May – Amanda Claridge, Canadian archaeologist. 7 May – Sir Paul Mellars, British archaeologist. 8 May – Harry Dornbrand, American aerospace engineer. 8 May – Zhuang Qiaosheng, Chinese geneticist and wheat breeder, member of the Chinese Academy of Sciences. 9 May – John H. Coates, Australian mathematician. 14 May – Bernard Bigot, French physicist and civil servant, director general of ITER (b. 1950) 9 June – Gordon M. Shepherd, American neuroscientist. 26 July – James Lovelock, English environmentalist (Gaia hypothesis) and futurist (b.
=== Photochromic compounds === Photochromic compounds have the ability to switch between a range or variety of colors. Their ability to display different colors lies in how they absorb light. Different isomeric manifestations of the molecule absorbs different wavelengths of light, so that each isomeric species can display a different color based on its absorption. These include photoswitchable compounds, which are proteins that can switch from a non-fluorescent state to that of a fluorescent one given a certain environment. The most common organic molecule to be used as a photochrome is diarylethene. Other examples of photoswitchable proteins include PADRON-C, rs-FastLIME-s and bs-DRONPA-s, which can be used in plant and mammalian cells alike to watch cells move into different environments.
Sources: en.wikipedia.org
== Signs and symptoms == Common symptoms of obstructive sleep disorder syndrome include unexplained daytime sleepiness, restless sleep, frequent awakenings and loud snoring (with periods of silence followed by gasps). Less common symptoms are morning headaches; insomnia; trouble concentrating; mood changes such as irritability, anxiety, and depression; bruxism (teeth grinding), forgetfulness; increased heart rate or blood pressure; erectile dysfunction, unexplained weight gain; increased urinary frequency or nocturia; frequent heartburn or gastroesophageal reflux; and heavy night sweats. Many people experience episodes of OSA transiently, for only a short period. This can be the result of an upper respiratory infection that causes nasal congestion, swelling of the throat, or tonsillitis that temporarily produces very enlarged tonsils. The Epstein-Barr virus, for example, is known to be able to increase the size of lymphoid tissue dramatically during acute infection, and OSA is fairly common in acute cases of severe infectious mononucleosis. Temporary spells of OSA syndrome may also occur in people who are under the influence of a drug (such as alcohol) that may relax their body tone excessively and interfere with normal arousal from sleep mechanisms.
The English word "organ" dates back to the twelfth century, referring to any musical instrument. By the late 14th century, the musical term's meaning had narrowed to refer specifically to the keyboard-based instrument. At the same time, a second meaning arose, in reference to a "body part adapted to a certain function". Plant organs are made from tissue composed of different types of tissue. The three tissue types are ground, vascular, and dermal. When three or more organs are present, it is called an organ system. The adjective visceral, also splanchnic, is used for anything pertaining to the internal organs. Historically, viscera of animals were examined by Roman pagan priests like the haruspices or the augurs in order to divine the future by their shape, dimensions or other factors. This practice remains an important ritual in some remote, tribal societies. The term "visceral" is contrasted with the term "parietal", meaning "of or relating to the wall of a body part, organ or cavity" The two terms are often used in describing a membrane or piece of connective tissue, referring to the opposing sides.
Organ on a chip applications: For example organoids can be used to model diseases with cells derived from patients or they can be used to investigate the development of different tissues (for example the nervous system) in humans and other animals. Some of these areas are further elaborated in the sections below:
=== GGQ catalytic site === The catalytic site that is responsible for the hydrolysis of the peptidyl tRNA is the GGQ site on eRF1. Current understanding of the GGQ site states that it enters the P-site of the ribosome, which is where the peptidyl tRNA is located, after a conformational change caused by the hydrolysis of GTP by eRF3. Furthermore, any mutation to the GGQ site renders eRF1 nonfunctional, thus the cells ability to successfully terminate Translation. This is due to the two glycine residues in GGQ to adopt a torsional angle that is only possible with two glycines. Without the proper angle, the active site for the reaction won't be able to function properly. In order nascent protein to be released the GGQ site needs to recruit a water molecule into the active site of the reaction. The method of recruitment for a single water molecule is still not understood completely. Once in position, the water molecule acts as a nucleophile, and attacks the carbonyl group of the ester bond between the nascent protein and the tRNA. The hydrolysis of the ester bond causes the release of the nascent protein and the disassembly of the ribosome and termination complex.
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.
Rodent studies reported increased endurance and fat oxidation after GW501516 exposure. Long-term studies also found higher rates of some tumors, which led to halted development.