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 2026-04-14 and is reviewed periodically as new material appears.
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.
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.
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.
| 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. |
Anti-doping laboratories detect GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be used in some programs. Detection depends on factors such as dose, timing, metabolism, and the sensitivity of the assay. Published methods describe limits of detection in the low nanogram per milliliter range for related compounds. Exact detection windows are not fixed for all situations and remain an area of ongoing study.
Products sold as cardarine have been found to contain incorrect compounds, variable amounts, or no active ingredient at all. Independent testing is required to verify identity and purity. Common analytical approaches include high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance for structural confirmation. These methods can distinguish GW501516 from related PPAR agonists and from unrelated steroids. For regulators and researchers, such verification is central to interpreting both biological results and adverse event reports.
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.
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.
== Bibliography == Furtado, Charles F. (1991). "Appendix 1: Draft Treaty on the Union of Sovereign States—27 June 1991 [FBIS]". Nationalities Papers. 19 (1): 93–114. doi:10.1080/00905999108408190. ISSN 0090-5992. Retrieved 13 May 2026. (New Union Treay, draft text of 27 June 1991, English translation)
=== Legal status === On 24 February 2022, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Kapruvia, intended for treatment of moderate-to-severe pruritus associated with chronic kidney disease. The applicant for this medicinal product is Vifor Fresenius Medical Care Renal Pharma France. Difelikefalin was approved for medical use in the European Union in April 2022.
== References == Cramer, James (1964). The World's Police. London: Cassell. Scouting on Two Continents, by Major Frederick Russell Burnham, D.S.O. LC call number: DT775 .B8 1926. (1926) Radford, M., 1994. Service Before Self, privately published. Gibbs, P., & Phillips, H., 2000. The History of the British South Africa Police, Something of Value Publications, Victoria, Australia. Kent Rasmussen, R., & Rubert, S. C., 1990. Historical Dictionary of Zimbabwe, Scarecrow Press, Metuchen, N.J., US. Brown, Robert K.: American mercenaries in Africa – How to be a Soldier of Fortune in Rhodesia, Soldier of Fortune Magazine, First ever issue 1976. Lott, Jack: "'Run the bastards down!' C.A.T.U. tracks terrorists – Rhodesia's civilian tracking unit". Soldier of Fortune Magazine, July 1979
=== Determination of status === Even when the evolutionary origin of a particular coding sequence has been established, there is still a lack of consensus about what constitutes a genuine de novo gene birth event. One reason for this is a lack of agreement on whether or not the entirety of the sequence must be non-genic in origin. For protein-coding de novo genes, it has been proposed that de novo genes be divided into subtypes based on the proportion of the ORF in question that was derived from a previously noncoding sequence. Furthermore, for de novo gene birth to occur, the sequence in question must be a gene which has led to a questioning of what constitutes a gene, with some models establishing a strict dichotomy between genic and non-genic sequences, and others proposing a more fluid continuum. All definitions of genes are linked to the notion of function, as it is generally agreed that a genuine gene should encode a functional product, be it RNA or protein. There are, however, different views of what constitutes function, depending whether a given sequence is assessed using genetic, biochemical, or evolutionary approaches. The ambiguity of the concept of 'function' is especially problematic for the de novo gene birth field, where the objects of study are often rapidly evolving.
Breast augmentation with fat-grafts (adipocyte tissue) harvested from the body of the patient (autologous fat) is indicated for women requiring breast reconstruction, the surgical correction of a congenital defect, and the æsthetic enhancement of the bust.
Sources: en.wikipedia.org
haemoglobin F (foetal haemoglobin, HbF), consisting of two alpha (α-globin) and two gamma (γ-globin) chains. This dominates during foetal development and until about 6 weeks of age. Afterwards, haemoglobin A remains dominant throughout life. haemoglobin A (adult haemoglobin, HbA), which consists of two alpha and two beta (β-globin) chains. This is the most common human haemoglobin tetramer, accounting for over 97% of the total red blood cell haemoglobin in normal adults. Haemoglobin B2 (HbA2) is a second form of adult haemoglobin and is composed of two alpha and two delta (δ-globin) chains. This haemoglobin typically comprises 1–3% of haemoglobin in adults. β-globin is encoded by the HBB gene on human chromosome 11; mutations in this gene produce variants of the protein which are implicated with abnormal hemoglobins. The mutation that causes sickle cell disease results in an abnormal haemoglobin known as haemoglobin S (HbS), which replaces HbA in adults. The human genome contains a pair of genes for β-globin; in people with sickle cell disease, both genes are affected, and the erythropoietic cells in the bone marrow will only create HbS. In people with sickle cell trait, only one gene is abnormal; erythropoiesis generates a mixture of normal HbA and sickle HbS. The person has very few, if any, symptoms of sickle cell disease but carries the gene and can pass it on to their children. Sickle cell disease has an autosomal recessive pattern of inheritance.
Mandelbaum (1956), professor at the University of Pennsylvania School of Design Kenneth Silverman (1956), professor at New York University and Pulitzer Prize-winning biographer Robert Alter (1957), professor of Hebrew and comparative literature at the University of California, Berkeley; president of the Association of Literary Scholars, Critics, and Writers Stanley Corngold (1957), professor of literature at Princeton University George Dargo (1957), legal scholar, professor at New England Law Boston Erich S. Gruen (1957), classicist and ancient historian; president of the Society for Classical Studies in 1992 Stanley Insler (1957), philologist and professor at Yale University Jonathan Lubin (1957), professor of mathematics at Brown University; introduced Lubin–Tate formal group law Robert Chazan (1958), professor of Judaic studies at New York University Gerald Feldman (1958), historian who specializes in 20th-century German history; professor at University of California, Berkeley Robert M. Fogelson (1958), urban historian at Massachusetts Institute of Technology Robert W.
=== Hyperbaric oxygen === In 2015, a Cochrane review concluded that for people with diabetic foot ulcers, hyperbaric oxygen therapy reduced the risk of amputation and may improve the healing at 6 weeks. However, there was no benefit at one year, and the quality of the reviewed trials was inadequate to draw strong conclusions.
== Duty of care == In the UK, in April 2008, the Corporate Manslaughter Act was strengthened to target company directors as well as their drivers in cases of road deaths involving vehicles used on business. The Police have said they now treat every road death as 'an unlawful killing' and have the power to seize company records and computers during their investigations. They will bring prosecutions against company directors who fail to provide clear policies and guidance for their employees driving at work. Unfortunately, in the UK a number of businesses are failing to meet their duty of care. In particular prosecutions can be brought against company directors for failing to meet their duty of care and allowing HGV driver hours to exceed the legal limits. Failure to comply with EU rules can result in a fixed penalty of up to £300, a graduated deposit of up to £1500 or you could be summoned to court. Directors and business owners may not be aware that privately owned vehicles used for business journeys are treated exactly the same as company owned vehicles. Directors have an equal responsibility under the law to ensure these vehicles are also roadworthy and correctly insured. It is vital that every company has a 'Driving at Work' policy in place covering every element of their business vehicle operation, no matter how few vehicles are involved and who owns them. Every employee driving for business is required to sign up to the policy. In this way, the directors can reduce the risk of being prosecuted and a possible custodial sentence.
Sources: en.wikipedia.org
=== Fermentation === The company Evolva has developed a genetically modified yeast which can produce vanillin. Because the microbe is a processing aid, the resulting vanillin would not fall under U.S. GMO labeling requirements, and because the production is nonpetrochemical, food using the ingredient can be said to contain no artificial ingredients. The biosynthetic process starts with glucose, or any sugar that can be converted into erythrose 4-phosphate (which leads to 3-dehydroshikimic acid). The end product is 98% pure and is also considered natural in the EU. Using ferulic acid (a chemical found in rice) as an input and a specific non GMO species of Amycolatopsis bacteria, vanillin can be produced. Many other bacteria, either GMO or non-GMO, can be used for the same purpose. However, because vanillin inhibits the growth of free-floating bacteria, yields have been low. This can be overcome through the formation of biofilms, which has been done with the non-GMO B. subtilis strain CCTCC M2011162. However, using ferulic acid as the starting material does not qualify for "natural ingredient" in the EU. Biotransformation of eugenol (from cloves) into vanillin by non-GMO microorganisms has also been reported. The same has been reported for guaiacol and guaicyl lignin (from conifers). These starting materials do not qualify for "natural ingredient" in the EU.
=== Excretion === Estradiol is excreted in the form of glucuronide and sulfate estrogen conjugates in urine. Following an intravenous injection of labeled estradiol in women, almost 90% is excreted in urine and feces within 4 to 5 days. Enterohepatic recirculation causes a delay in excretion of estradiol.
==== Separation of unbound small molecules and ligand-protein complexes ==== Affinity selection is followed by the removal of unbound small molecules via ultrafiltration or size-exclusion chromatography, making only protein-bound ligands available for downstream analysis. Several types of ultrafiltration have been reported with varying degrees of throughput, including pressure-based, centrifugal, and precipitation-based ultrafiltration. Under both pressure-based and centrifugal formats, unbound small molecules are forced through a semipermeable membrane that excludes proteins on the basis of size. Multiple washing steps are required after ultrafiltration to ensure complete removal of unbound small molecules. Ultrafiltration can also be confounded by non-specific adsorption of unbound small molecules to the membrane. A group at the University of Illinois published a screening strategy involving amyloid-beta, in which ligands were used to stabilize the protein and prevent its aggregation. Ultrafiltration was used to precipitate aggregated amyloid-beta and remove unbound ligands, while the ligand-stabilized protein was detected and quantified using mass spectrometry. Size-exclusion chromatography (SEC) is more widely used in industrial drug discovery and has the advantage of more efficient removal of unbound compounds as compared to ultrafiltration. Size-exclusion approaches have been described in both high-performance liquid chromatography (HPLC) based and spin column formats.
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.
Cardarine is a common name for GW501516, a synthetic PPARδ agonist developed for research. It has not been approved as a medication in any country. It is classified as an unapproved drug and a prohibited substance in sport.