If you have been reading about LC-MS/MS 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.
Updated 2026-04-22. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| 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 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.
The pharmacological interest in cardarine centers on PPARδ activation and its downstream effects on lipid handling and mitochondrial function. In animal studies, PPARδ agonists have been associated with changes in exercise endurance and fatty acid utilization, though results vary by model and protocol. Human data remain sparse, and the absence of large controlled trials limits conclusions about efficacy. Researchers often describe the compound as a tool for probing PPARδ biology rather than a proven therapeutic agent.
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.
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.
Cardarine is a common name for GW501516, a synthetic compound developed in the 1990s through research collaborations involving GlaxoSmithKline. It belongs to a class of molecules known as peroxisome proliferator-activated receptor delta agonists. Early studies explored its effects on lipid metabolism and energy expenditure in animal models. The compound was never approved as a human medicine, and clinical development was discontinued. In the years since, it has appeared in fitness and bodybuilding communities as a performance-enhancing substance. Regulatory agencies classify it as an unapproved drug.
The coronary sinus is a large vein that drains into the right atrium, and receives most of the venous drainage of the heart. It receives blood from the great cardiac vein (receiving the left atrium and both ventricles), the posterior cardiac vein (draining the back of the left ventricle), the middle cardiac vein (draining the bottom of the left and right ventricles), and small cardiac veins. The anterior cardiac veins drain the front of the right ventricle and drain directly into the right atrium. Small lymphatic networks called plexuses exist beneath each of the three layers of the heart. These networks collect into a main left and a main right trunk, which travel up the groove between the ventricles that exists on the heart's surface, receiving smaller vessels as they travel up. These vessels then travel into the atrioventricular groove, and receive a third vessel which drains the section of the left ventricle sitting on the diaphragm. The left vessel joins with this third vessel, and travels along the pulmonary artery and left atrium, ending in the inferior tracheobronchial node. The right vessel travels along the right atrium and the part of the right ventricle sitting on the diaphragm. It usually then travels in front of the ascending aorta and then ends in a brachiocephalic node.
=== Refractory coeliac disease === About 1.5% of those with coeliac disease develop refractory coeliac disease (RCD), which is the persistence of symptoms of malabsorption and villous atrophy despite at least one year of the GFD. RCD has a high mortality and morbidity rate, is associated with more severe symptoms and is more common in older individuals (50<). Those with RCD are often referred to specialists and the diagnostic process usually includes monitoring compliance with the GFD, confirming the initial diagnoses of coeliac disease, and excluding alternative explanations for small intestine damage such as Crohn's disease, peptic duodenitis, small intestinal bacterial overgrowth, hypogammaglobulinemia, common variable immunodeficiency, autoimmune enteropathy, tropical sprue, collagenous sprue, and eosinophilic enteritis. There are two subtypes of RCD, type 1 and type 2. Biopsies of the duodenum and analysis of the intraepithelial lymphocytes in the duodenum are required to distinguish between the two types. Type 2 RCD is characterised by abnormal T cells in the small intestine; these findings are absent in type 1 RCD. In type 2 RCD, healthy lymphocytes are replaced by abnormal lymphocytes, increasing the risk of complications such as enteropathy-associated T-cell lymphoma (EATL), severe malabsorption, and ulcerative jejunoileitis, and results in poorer outcomes. Type 1 RCD is treated with steroids, azathioprine, and budesonide. The treatment of type 2 RCD is more complicated as it often does not improve with steroids, and azathioprine may increase the risk of EATL.
Palestinian militancy has been the main focus of the IDF ever since, especially during the First and Second Intifadas, Operation Defensive Shield, the Gaza War, Operation Pillar of Defense, and Operation Protective Edge, causing the IDF to change many of its values and publish the IDF Spirit. The Lebanese Shia organization Hezbollah has also been a growing threat, against which the IDF fought an asymmetric conflict between 1982 and 2000, as well as a full-scale war in 2006.
== Hosts and disease development == Penicillium expansum has a wide host range, causing similar symptoms on fruits which include apples, pears, cherries, and citrus. Initial infection most often occurs at sites of fruit injury, such as bruises or puncture wounds. Although infections may start in the field, infected spots often become evident post-harvest, and expand while fruit is in storage. Infected areas are clearly delineated and light brown, and soft decaying tissue can be easily "scooped" out of the surrounding healthy tissue. Spore masses later appear on the surfaces of infected fruit, initially appearing as white mycelium, then turning blue to blue-green in color as the asexual spores mature. Fruit affected by P. expansum typically has an earthy, musty odor. Lesions measure 1–1.25 inches in diameter eight to ten weeks after infection if kept under cold storage conditions. Age factors into P. expansum infection, in that overripe or mature fruits are most susceptible to infection, while those picked underripe are less likely to become infected. In apples, the colors of the lesions may vary with variety, from lighter-brown on green and yellow apple varieties, to dark-brown on the deeper-red and other darker-color varieties. Varieties particularly susceptible to P. expansum infection include McIntosh, Golden Supreme, and Golden Delicious. Both sweet and sour cherries are affected by P. expansum. Cherry varieties found to be particularly susceptible to P. expansum infection were mainly early varieties, including Navalinda and Burlat.
Sources: en.wikipedia.org
Both his parents died from cancer during his first two years at Cambridge. His father was 60 and his mother was 58. As an undergraduate Sanger's beliefs were strongly influenced by his Quaker upbringing. He was a pacifist and a member of the Peace Pledge Union. It was through his involvement with the Cambridge Scientists' Anti-War Group that he met his future wife, Joan Howe, who was studying economics at Newnham College. They courted while he was studying for his Part II exams and married after he had graduated in December 1940. Sanger, although brought up and influenced by his religious upbringing, later began to lose sight of his Quaker related ways. He began to see the world through a more scientific lens, and with the growth of his research and scientific development he slowly drifted farther from the faith he grew up with. He had nothing but respect for the religious and states he took two things from it, truth and respect for all life. Under the Military Training Act 1939 he was provisionally registered as a conscientious objector, and again under the National Service (Armed Forces) Act 1939, before being granted unconditional exemption from military service by a tribunal. In the meantime he undertook training in social relief work at the Quaker centre, Spicelands, Devon and served briefly as a hospital orderly. Sanger began studying for a PhD in October 1940 under N.W. "Bill" Pirie. His project was to investigate whether edible protein could be obtained from grass. After little more than a month Pirie left the department and Albert Neuberger became his adviser.
Angered by the snub, Gaddafi plotted with Abu Nidal to assassinate Hassan in 1987, but the plot was aborted. In 1981, the new US president, Ronald Reagan, pursued a hardline approach to Libya, viewing it as a puppet regime of the Soviet Union. Gaddafi played up his commercial relationship with the Soviets, revisiting Moscow in 1981 and 1985, and threatening to join the Warsaw Pact. The Soviets were nevertheless cautious of Gaddafi, seeing him as an unpredictable extremist. In August 1981, the US staged military exercises in the Gulf of Sirte – an area which Libya claimed. The US shot down two Libyan Su-22 planes which were on an intercept course. Closing down Libya's embassy in Washington, Reagan advised US companies operating in Libya to reduce Americans stationed there. In December 1981, the White House claimed Gaddafi had dispatched a hit squad to assassinate Reagan, allegedly led by Carlos the Jackal, who had been living in Libya under Gaddafi's protection after the 1975 OPEC siege. Secretary of State Alexander Haig, Defense Secretary Caspar Weinberger, Counselor to the President Edwin Meese, chief of staff James Baker, and deputy chief of staff Michael Deaver were considered potential targets and given special security. US ambassador to Italy Maxwell M. Rabb, who was Jewish, was urgently recalled due to threats against his life. Gaddafi denied the allegations. Gaddafi was accused of having ties to the Lebanese Armed Revolutionary Factions, which had murdered US military attaché Charles R. Ray and Israeli diplomat Yacov Barsimantov in Paris.
=== Filamentous fungi === Fungi are natural decomposers of many ecosystems. As a result, it is able to secrete large amounts of enzymes, more so than bacterial based systems. However, utilizing fungi as expression systems has seen several barriers, especially due to the lack of knowledge regarding fungal genetics due to its inherent complexity. The filamentous fungi specifically have been a host system of interest, and includes Penicillium (where penicillin was derived), Trichoderma reesei, and Aspergillus niger. Filamentous fungi are efficient at producing extracellular proteins, bypassing the additional step of cell breaking to extract proteins. Some also have inexpensive growth and media conditions. Fungi also contain glycolysation and modification capabilities that are helpful for eukaryotic proteins. Additionally, they have also successfully produced vaccine related proteins, and some filamentous fungi have been deemed GRAS by the FDA. However, the major drawback of using this host system is that yields are extremely low and not economically viable. Moreover, the low amount of protein that is produced is often degraded by fungal proteases. Some approaches to address this have been using protease deficient strains. Researchers are also attempting different gene disruption methods. With a better understanding of fungal gene regulation and expression, we can expect filamentous fungi to become a possibly viable host system.
10 Ca(OH)2 + 6 H3PO4 → Ca10(PO4)6(OH)2 + 18 H2O The ability to synthetically replicate hydroxyapatite has invaluable clinical implications, especially in dentistry. Each technique yields hydroxyapatite crystals of varied characteristics, such as size and shape. These variations have a marked effect on the biological and mechanical properties of the compound, and therefore these hydroxyapatite products have different clinical uses.
Through discretionary grants, federal agencies set program objectives, eligibility criteria, and funding conditions in Notices of Funding Opportunity (NOFOs), which can shape how artificial intelligence technologies are developed and deployed by funding recipients. Guidance issued by the Office of Management and Budget (OMB) to implement the Executive Order's policies applied risk-management requirements primarily to procurement and agency uses of AI, while generally excluding federal financial assistance programs. In April 2024, the Federal Trade Commission (FTC) announced Operation AI Comply, a cross-agency initiative to ensure that AI products and marketing claims comply with existing consumer-protection, fair-credit, and truth-in-advertising laws. The FTC stated that companies deploying AI systems must "keep their AI claims in check" and warned that false or misleading representations about AI capabilities would be subject to enforcement under the FTC Act. In 2024, a bipartisan House task force released a report on artificial intelligence, while representatives Jay Obernolte and Lori Trahan subsequently developed a bipartisan proposal concerning AI regulation.
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.
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.