LC-MS/MS 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.
Last reviewed on 2026-02-23. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| 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 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.
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.
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.
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.
ACTA2 (actin alpha 2) is an actin protein with several aliases including alpha-actin, alpha-actin-2, aortic smooth muscle or alpha smooth muscle actin (α-SMA, SMactin, alpha-SM-actin, ASMA). Actins are a family of globular multi-functional proteins that form microfilaments. ACTA2 is one of six different actin isoforms and is involved in the contractile apparatus of smooth muscle. ACTA2 (as with all the actins) is extremely highly conserved and found in nearly all mammals. In humans, ACTA2 is encoded by the ACTA2 gene located on 10q22-q24. Mutations in this gene cause a variety of vascular diseases, such as thoracic aortic disease, coronary artery disease, stroke, Moyamoya disease, and multisystemic smooth muscle dysfunction syndrome. ACTA2 (commonly referred to as alpha-smooth muscle actin or α-SMA) is often used as a marker of myofibroblast formation. Studies have shown that ACTA2 is associated with TGF-β pathway that enhances contractile properties of hepatic stellate cells leading to liver fibrosis and cirrhosis.
=== Brand names === Metandienone was introduced and formerly sold primarily under the brand name Dianabol. It has also been marketed under a variety of other brand names including Anabol, Averbol, Chinlipan, Danabol, Dronabol, Metanabol, Methandon, Naposim, Reforvit-B, and Vetanabol among others.
== Nomenclature == This enzyme belongs to the family of oxidoreductases, specifically those acting on CH or CH2 groups with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is (S)-2,3,4,5-tetrahydropyridine-2,6-dicarboxylate:NAD(P)+ 4-oxidoreductase. Other names in common use include:
=== Football-only alignment (2020-2025) === In February 2019, in conjunction with the Wisconsin Football Coaches Association, the WIAA released a sweeping football-only realignment for Wisconsin to commence with the 2020 football season and run on a two-year cycle. The East Central Conference retained six members for football (Berlin, Kettle Moraine Lutheran, Kewaskum, Plymouth, Ripon and Waupun) and welcomed two football-only members: Port Washington of the North Shore Conference, and Sheboygan Falls of the Eastern Wisconsin Conference. This alignment remained in place for the 2022-2023 realignment cycle. For the 2024-2025 cycle, the East Central Conference was whittled down to six members, with returnees Kettle Moraine Lutheran, Kewaskum, Plymouth and Port Washington being joined by Beaver Dam and Watertown of the Badger Conference. The East Central Conference was realigned out of existence for the 2026-2027 realignment cycle.
The Roast Town concept received poor marks in market tests and was quickly discontinued. Pierce and his team left the company and it sold all of its 354 company-owned locations to RTM Restaurant Group, an existing Arby's franchise, for $71 million. Another marketing concept that was tried was a dual-brand venture that was started in 1995 with ZuZu's Handmade Mexican Grill. The marketing venture was a failure resulting in lawsuits being filed by each company against the other. In 1990, Arby's would acquire Daddy-O's Express, a double drive-through hamburger chain. The chain would expand to 13 locations with all closing by the late 90's. In 1992, Les Franchises P.R.A.G. Inc. opened the first Arby's franchise in the Canadian province of Quebec. It was also the 100th location to open in Canada and joins other locations that were then operating in the provinces of Ontario, Alberta, New Brunswick, Nova Scotia, Manitoba, British Columbia, and Saskatchewan. The Quebec location also sold the uniquely French-Canadian dish called poutine. In 2002, Arby's returned to operating restaurants by purchasing the second largest Arby's franchisee, Sybra Inc., with 293 locations out of bankruptcy outbidding RTM so as to prevent RTM from becoming too large. RTM was purchased by Arby's on July 25, 2005. In November 2002, Access Now filed a lawsuit against RTM, then a franchise of Triarc, that some 800 of their stores did not comply with the Americans with Disabilities Act of 1990 (ADA). The lawsuit had no liability damages except for lawyer fees.
Sources: en.wikipedia.org
== Catabolic hormones == There are many signals that control catabolism. Most of the known signals are hormones and the molecules involved in metabolism itself. Endocrinologists have traditionally classified many of the hormones as anabolic or catabolic, depending on which part of metabolism they stimulate. The so-called classic catabolic hormones known since the early 20th century are cortisol, glucagon, and adrenaline (and other catecholamines). In recent decades, many more hormones with at least some catabolic effects have been discovered, including cytokines, orexin (known as hypocretin), and melatonin.
"The discovery of radium". Lateral Science. UK. 8 July 2012. Archived from the original on 9 March 2016. Retrieved 13 May 2017. Radium water bath in Oklahoma. markwshead.com (photographic images). "Radium, radioactive". NLM Hazardous Substances Databank. U.S. National Institutes of Health. Archived from the original on 1 July 2018. "Annotated bibliography for radium". Alsos Digital Library for Nuclear Issues. Lexington, VA: Washington and Lee University. Archived from the original on 25 June 2019. "Radium". The Periodic Table of Videos. University of Nottingham.
Oxyntomodulin (often abbreviated OXM) is a naturally occurring 37-amino acid peptide hormone found in the colon, produced by the oxyntic (fundic) cells of the oxyntic (fundic) mucosa. It has been found to suppress appetite. The mechanism of action of oxyntomodulin is not well understood. It is known to bind both the GLP-1 receptor and the glucagon receptor, but it is not known whether the effects of the hormone are mediated through these receptors or through an unidentified receptor. Oxyntomodulin has been linked to entrainment of the liver's circadian clock. Oxyntomodulin has been investigated as a blood-glucose regulation agent in connection with diabetes.
Betaine transporter (SLC6A12) InterPro: IPR002983 Creatine transporter (SLC6A8) InterPro: IPR002984 Dopamine neurotransmitter transporter (SLC6A3) InterPro: IPR002436 Inebriated neurotransmitter transporter InterPro: IPR002944 GABA neurotransmitter transporter GAT-1 (SLC6A1) InterPro: IPR002980 GABA neurotransmitter transporter GAT-2 (SLC6A13) InterPro: IPR002981 GABA neurotransmitter transporter GAT-3 (SLC6A11) InterPro: IPR002982 Glycine neurotransmitter transporter, type 1 (SLC6A9) InterPro: IPR003028 Noradrenaline neurotransmitter transporter (SLC6A2) InterPro: IPR002435 Orphan neurotransmitter transporter (SLC6A15) InterPro: IPR002438 Serotonin (5-HT) neurotransmitter transporter, N-terminal (SLC6A4) InterPro: IPR013086 Taurine transporter (SLC6A6) InterPro: IPR002434
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.
It binds to and activates PPAR delta, a nuclear receptor that controls expression of genes related to fatty acid oxidation. This mechanism can alter energy metabolism in animal models. It is not a direct stimulant or fat-burning enzyme.