LC-MS/MS raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-06-09 and is reviewed periodically as new material appears.
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.
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.
GW501516 acts on PPARδ, a nuclear receptor that helps regulate fatty acid oxidation and energy homeostasis. In animal studies, activation of this receptor was associated with increased endurance and changes in lipid metabolism. Human trials examined effects on blood lipids and other metabolic markers, but the compound did not advance to approval. Rodent studies later reported tumors in multiple tissues at doses used in those experiments. Whether those findings translate to human risk remains uncertain, and the clinical relevance of the animal data is still debated.
Regulatory bodies treat GW501516 as a prohibited substance in competitive sport. The World Anti-Doping Agency added it to the prohibited list, and it falls under classes covering metabolic modulators and hormone-related agents. It is not approved by drug regulators for human use, and it is not a lawful dietary supplement. Products sold under the cardarine name may contain unlisted ingredients or different compounds. Because no approved product exists, quality and identity are not guaranteed by pharmaceutical manufacturing standards.
| 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. |
Published studies have examined GW501516 in animal models of obesity, insulin resistance, and exercise endurance. Early human trials reportedly ended, and development was discontinued after preclinical findings raised concerns about cancer in some rodent studies. Regulatory agencies have not approved cardarine for any medical use. Its availability through non-pharmaceutical channels raises questions about identity, purity, and legal status that are separate from its laboratory pharmacology. Those questions are often addressed through analytical testing rather than assumptions about product labels.
Cardarine is a common name for GW501516, also GW-1516, a synthetic compound developed as a peroxisome proliferator-activated receptor delta (PPARδ) agonist. It belongs to a class of agents that modulate gene transcription related to lipid and energy metabolism. The compound was studied in preclinical and early clinical research for metabolic and cardiovascular conditions, but it did not progress to approved therapeutic use. Its name appears in fitness and sports contexts despite not being approved as a drug.
Safety discussions about cardarine frequently cite rodent carcinogenicity findings reported in the 2000s. In those studies, treated animals developed tumors at multiple sites, leading sponsors to discontinue clinical development. The relevance of these findings to humans has not been resolved, but they are a major reason the compound is not approved. Current literature emphasizes uncertainty about long-term effects and the risks of unregulated use. Regulators and health agencies have not established a safe human exposure level.
Cardarine is a synthetic compound also known as GW501516, GW-501516, and sometimes endurobol. It was developed as a selective agonist of peroxisome proliferator-activated receptor delta, a nuclear receptor involved in fatty acid oxidation and energy metabolism. The compound was studied in preclinical models for metabolic and cardiovascular conditions, but it did not become a marketed human medicine. In regulatory and anti-doping contexts, it is treated as a prohibited substance rather than a licensed medicine.
== Background == What later became the nation of South Africa was not politically unified in the late nineteenth century. The territory had four distinct entities: the two British colonies of Cape Colony and Natal; and the two Boer republics of the Orange Free State and the South African Republic, more commonly referred to as the Transvaal.
==== Post-traumatic growth in constructive journalism ==== The phenomenon of PTG is applicable to many disciplines. The construct is important not only for just soldiers, emergency responders, and survivors of traumatic events, but on average, for everyday citizens facing typical adversity. One way to expose citizens to stories of PTG is through constructive journalism. Constructive journalism, as defined by PhD student Karen McIntyre at University of North Carolina Chapel Hill, is "an emerging style of journalism in which positive psychology techniques are applied to news work with the aim of engaging readers by creating more productive news stories, all while maintaining core journalistic functions". Cathrine Gyldensted, an experienced reporter with a Masters in applied positive psychology and coauthor of two books, demonstrated that typical news reporting, which is associated with negative valence, harms mood. Using PTG to focus on victims' strengths and instances of overcoming adversity encourages readers to implement similar ideals in their own lives. "So the goal of positive psychology in well-being theory is to measure and to build human flourishing." Combining positive psychology constructs like PTG, PERMA, and "broaden and build" with journalism could potentially improve affect and inspire individuals about the benefits of positive psychology. PERMA not only plays a role in our own personal lives but also can be used for public major news stories.
Solid phase microextraction, or SPME, is a solid-phase extraction sampling technique that involves the use of a fiber coated with an extracting phase, that can be a liquid (polymer) or a solid (sorbent), which extracts different kinds of analytes (including both volatile and non-volatile) from different kinds of media, that can be in liquid or gas phase. The quantity of analyte extracted by the fibre is proportional to its concentration in the sample as long as equilibrium is reached or, in case of short time pre-equilibrium, with help of convection or agitation.
Ataxia with oculomotor apraxia type 1 (AOA1), also known as early-onset ataxia with ocular motor apraxia and hypoalbuminemia, is a rare autosomal recessive disorder caused by mutations in the APTX gene. AOA1 usually begins as uncoordinated movements and ataxia at the age of four but can start manifesting between ages two and ten. Also, they develop oculomotor apraxia, dysarthric speech, myoclonic jerks, chorea, cognitive impairment, and neuropathy. Elevated levels of cholesterol, creatine kinase, and decreased levels of albumin can be seen. Patients usually start using wheelchair after 11 years since the onset of the symptoms. APTX gene codes for the protein Aprataxin, which might help DNA repair by the removal of adenylate groups from 5′-phosphate terminus at single-strand DNA nicks and gaps. It is most common in Japan and Portugal.
Sources: en.wikipedia.org
==== Enchondroma ==== Enchondromas are benign tumors of hyaline cartilage. Within a bone, enchondromas are often found in metaphyses. They can be found in many types of bone, including small bones, long bones, and the axial skeleton. X-ray of enchondromas shows well-defined borders and a stippled appearance. Presentation of multiple enchondromas is consistent with multiple enchondromatosis (Ollier Disease). Treatment of enchondromas involves surgical curettage and grafting.
== Biodegradation == Algae and some invertebrates such as protozoans, mollusks, and polychaetes have limited ability to metabolize PAHs. Some such organisms bioaccumulate disproportionate concentrations of PAHs in their tissues. PAH metabolism can vary substantially across invertebrate species. Most vertebrates metabolize and excrete PAHs relatively rapidly. Tissue concentrations of PAHs do not increase (biomagnify) from the lowest to highest levels of food chains. PAHs transform slowly to a wide range of degradation products. Biological degradation by microbes is a dominant form of PAH transformation in the environment. Soil-consuming invertebrates such as earthworms are claimed to speed PAH degradation, either through direct metabolism or by improving the conditions for microbial transformations. Abiotic degradation in the atmosphere and the top layers of surface waters can produce nitrogenated, halogenated, hydroxylated, and oxygenated PAHs; some of these compounds can be more toxic, water-soluble, and mobile than their parent PAHs.
== Erythrose 4-phosphate and phosphoenolpyruvate: phenylalanine, tyrosine, and tryptophan == Phenylalanine, tyrosine, and tryptophan, the aromatic amino acids, arise from chorismate. The first step, condensation of 3-deoxy-D-arabino-heptulosonic acid 7-phosphate (DAHP) from PEP/E4P, uses three isoenzymes AroF, AroG, and AroH. Each one of these has its synthesis regulated from tyrosine, phenylalanine, and tryptophan, respectively. The rest of the enzymes in the common pathway (conversion of DAHP to chorismate) appear to be synthesized constitutively, except for shikimate kinase, which can be inhibited by shikimate through linear mixed-type inhibition.
== Education == Kowalska received a master's degree in chemistry in 1968 and a PhD in physical chemistry in 1972, both from Higher Pedagogical School in Katowice, which became University of Silesia in Katowice. She conducted post-doctoral research at University of Salford in the UK, under the supervision of Hans Suschitzky. She received a habilitation degree in 1988 from Maria Curie-Skłodowska University, with the habilitation dissertation titled A New Thermodynamic Model of the Chromatographic Process and its Applications.
=== Irradiated red blood cells === Even after leucocyte filtration, a residual number of leucocytes remain in the red blood cell concentrate (<1 million per unit). These may be harmful for patients who have an impaired, reduced or not yet fully developed immune system, or if the blood donor and recipient are closely related. Therefore, such patients may be issued irradiated blood components, including irradiated red blood cells. X-ray or gamma sources are usually used for irradiation. When blood components are irradiated, the DNA is destroyed in any remaining white blood cells (leucocytes), which stops the leucocytes from being able to proliferate further. Although efficient in reducing the risk of transfusion reactions including fatal transfusion-associated graft-versus-host disease (TA-GvHD), irradiation is damaging to the red blood cell membrane, which can be seen as increased levels of haemolysis during storage. As a consequence, irradiated red blood cell concentrates are usually given a reduced shelf life. Therefore, irradiation of red blood cell concentrates is commonly only performed on demand or for specific parts of the supply.
Sources: en.wikipedia.org
The extent to which the findings of a clinical trial can be reliably extrapolated from the subjects who participated in the trial to a broader patient population and a broader range of clinical settings. (ICH E9) Global assessment variable
A few dozen American farmers purchased varying amounts of land by a variety of means including finding investors and selling off land holdings. Many followed the ethanol company model and formed an LLC with investments from neighboring farmers, friends, and family while some turned to investment companies. Some soy farmers either liquidated their Brazilian assets or switched to remote management from the US to return to farming there and implement new farming and business practices to make their US farms more productive. Others planned to sell their now expensive Bahia land to buy land cheaper land in the frontier regions of Piauí or Tocantins to create more soybean farms.
==== Relationship with Rod Blagojevich ==== Illinois Governor Rod Blagojevich appointed Pritzker to chair the Illinois Human Rights Commission in 2003. He held that position until 2006. After Pritzker left the chairmanship, Blagojevich appointed former White House counsel and federal judge Abner J. Mikva to succeed him. A controversial phone call between Pritzker and Blagojevich, which was recorded on an FBI wiretap, took place during the 2008 corruption scandal. The Chicago Tribune described Pritzker at the time as a "businessman with political ambitions". On the call, Blagojevich asked Pritzker whether he would like to be appointed state treasurer, to which Pritzker responded, "Yeah, that's the one I would want." He and Blagojevich also discussed filling Barack Obama's U.S. Senate seat, with Pritzker saying that appointing then-Secretary of State Jesse White would "cover you on the African-American thing" and that he was the "least offensive" Black candidate. After the Tribune released the recording during the 2018 gubernatorial election, Governor Bruce Rauner and Pritzker's Democratic primary opponents criticized his conduct. Pritzker responded: "I've not been accused of any wrongdoing.
=== Cycles related to the 3-hydroxypropionate cycle === A variant of the 3-hydroxypropionate cycle was found to operate in the aerobic extreme thermoacidophile archaeon Metallosphaera sedula. This pathway is called the 3-hydroxypropionate/4-hydroxybutyrate (3-HP/4-HB) cycle. Yet another variant of the 3-hydroxypropionate cycle is the dicarboxylate/4-hydroxybutyrate (DC/4-HB) cycle. It was discovered in anaerobic archaea. It was proposed in 2008 for the hyperthermophile archeon Ignicoccus hospitalis.
In PET scanning, a radioactive, biologically active substance, most often 18F-FDG, is injected into a patient, and the radiation emitted by the patient is detected to produce multiplanar images of the body. Metabolically more active tissues, such as cancer, concentrate the active substance more than normal tissues. PET images can be combined (or "fused") with anatomic (CT) imaging to more accurately localize PET findings and thereby improve diagnostic accuracy. The fusion technology has gone further to combine PET and MRI, similar to PET and CT. PET/MRI fusion, largely practiced in academic and research settings, could potentially play a crucial role in fine detail of brain imaging, breast cancer screening, and small joint imaging of the foot. The technology recently blossomed after passing the technical hurdle of altered positron movement in a strong magnetic field, thus affecting the resolution of PET images and attenuation correction.
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.
No. Cardarine is a PPARδ agonist, while selective androgen receptor modulators act on androgen receptors. The two classes differ in receptor target and downstream effects.