Anti-doping 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 2026-03-31 and is reviewed periodically as new material appears.
Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.
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.
Cardarine is a common name for GW501516, an investigational compound developed in the 1990s for metabolic conditions. It acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in lipid and energy metabolism. The compound is frequently mislabeled as a selective androgen receptor modulator, or SARM, but its molecular target is different. GW501516 reached early clinical testing before development was discontinued. It has no approved therapeutic use in any country. The name cardarine is not a formal international nonproprietary name.
Regulatory treatment varies, but cardarine is not approved as a medicine. Sports authorities list GW501516 as a prohibited substance, and it is banned at all times under the World Anti-Doping Agency code. Many countries restrict sales for human consumption, while online vendors market it as a research chemical. Such products may lack purity data, and their actual contents can differ from the label. Purchasing or possessing cardarine may carry legal consequences depending on jurisdiction. The compound is not a dietary supplement ingredient in regulated markets.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Prohibited in sport | Listed by WADA as a metabolic modulator. |
| Approved medical use | None in major jurisdictions | Not a registered drug. |
| Common test matrix | Urine | Most anti-doping samples use urine. |
| Typical detection method | LC-MS/MS | Detects parent compound and metabolites. |
| Reference standard storage | -20 °C, desiccated | Typical for analytical standards. |
GW501516 binds and activates PPARδ, a nuclear receptor that influences transcription of genes involved in fatty acid oxidation and energy use. Activation shifts some metabolic pathways in preclinical models, which is why the compound has been studied for lipid disorders and exercise-related endpoints. The exact downstream effects in humans are incompletely mapped. PPARδ is expressed in many tissues, including skeletal muscle, liver, and adipose tissue, so broad activation may have varied consequences. Researchers continue to examine how selective or partial activation might alter the balance between benefits and risks.
Published human data are sparse and mostly come from early-phase trials. Those studies examined short-term changes in lipids, glucose, and exercise capacity, but they were not large enough to establish efficacy or long-term safety. Some animal experiments reported increased running endurance, yet such findings do not prove a performance benefit in people. Anti-doping laboratories detect GW501516 and its metabolites in urine or blood using liquid chromatography-tandem mass spectrometry. Detection windows depend on dose, sample type, and individual metabolism. The method is sensitive enough to identify trace residues in tested samples.
Early clinical research explored GW501516 for lipid disorders, obesity, and diabetes. Some short-term human studies reported changes in HDL cholesterol, LDL cholesterol, and triglycerides. The development program was discontinued after rodent studies showed dose-dependent tumor formation in multiple tissues, including liver, bladder, stomach, and skin. These findings raised concerns about long-term cancer risk in humans. Because human exposure data are limited, the clinical significance of the rodent tumors remains uncertain.
Literature on cardarine often separates receptor pharmacology from toxicology. Mechanistic papers describe PPARδ activation and gene expression changes, while safety assessments focus on carcinogenicity and species differences. Questions remain about whether rodent tumors arise through PPARδ-dependent or off-target mechanisms. Another open area is how human metabolism and exposure compare with those in animal studies. Analytical methods such as liquid chromatography–mass spectrometry are used to confirm identity in biological and product samples.
Shubich used a 0.5% acidic solution of Bismarck brown to contrastively stain mast cell granules in yellow-brown without staining other types of cells. Hematoxylin & Eosin (H&E) staining is non-effective for selective mast cell staining because hematoxylin does not bind to mast cell granule components. It can be used to counterstain cellular nuclei of mastocytes.
Clinical example: Diazepam has long been a drug of choice for status epilepticus; its high lipid solubility means it gets absorbed with equal speed whether given orally, or rectally (nonintravenous routes are convenient outside of hospital settings), but diazepam's high lipid solubility also means it does not remain in the vascular space, but soon redistributes into other body tissues. So, it may be necessary to repeat diazepam doses to maintain peak anticonvulsant effects, resulting in excess body accumulation. Lorazepam is a different case; its low lipid solubility makes it relatively slowly absorbed by any route other than intravenously, but once injected, it will not get significantly redistributed beyond the vascular space. Therefore, lorazepam's anticonvulsant effects are more durable, thus reducing the need for repeated doses. If a person is known to usually stop convulsing after only one or two diazepam doses, it may be preferable because sedative after effects will be less than if a single dose of lorazepam is given (diazepam anticonvulsant/sedative effects wear off after 15–30 minutes, but lorazepam effects last 12–24 hours). The prolonged sedation from lorazepam may, however, be an acceptable trade-off for its reliable duration of effects, particularly if the person needs to be transferred to another facility. Although lorazepam is not necessarily better than diazepam at initially terminating seizures, lorazepam is, nevertheless, replacing diazepam as the intravenous agent of choice in status epilepticus.
== Regulation == AADC regulation, especially as it relates to L-DOPA decarboxylation, has been studied extensively. AADC has several conserved protein kinase A (PKA) and protein kinase G recognition sites, with residues S220, S336, S359, T320, and S429 all as potential phosphate acceptors. In vitro studies have confirmed PKA and PKG can both phosphorylate AADC, causing a significant increase in activity. In addition, dopamine receptor antagonists have been shown to increase AADC activity in rodent models, while activation of some dopamine receptors suppresses AADC activity. Such receptor-mediated regulation is biphasic, with an initial short term activation followed by long term activation. The short term activation is thought to proceed through kinase activation and subsequent phosphorylation of AADC, while the sensitivity of long term activation to protein translation inhibitors suggests regulation of mRNA transcription.
Sources: en.wikipedia.org
== Disorders == The body's hemostasis system requires careful regulation in order to work properly. If the blood does not clot sufficiently, it may be due to bleeding disorders such as hemophilia or immune thrombocytopenia; this requires careful investigation. Over-active clotting can also cause problems; thrombosis, where blood clots form abnormally, can potentially cause embolisms, where blood clots break off and subsequently become lodged in a vein or artery. Hemostasis disorders can develop for many different reasons. They may be congenital, due to a deficiency or defect in an individual's platelets or clotting factors. A number of disorders can be acquired as well, such as in HELLP syndrome, which is due to pregnancy, or Hemolytic-uremic syndrome (HUS), which is due to E. coli toxins.
The four substrates of this enzyme are 3-hydroxybenzoic acid, reduced nicotinamide adenine dinucleotide (NADH), oxygen and a proton. Its products are gentisic acid, oxidised NAD+, and water. The enzyme is a flavin-containing monooxygenase that uses molecular oxygen as oxidant and incorporates one of its atoms into the starting material. The systematic name of this enzyme class is 3-hydroxybenzoate,NADH:oxygen oxidoreductase (6-hydroxylating). Other names in common use include 3-hydroxybenzoate 6-hydroxylase, m-hydroxybenzoate 6-hydroxylase, and 3-hydroxybenzoic acid-6-hydroxylase. It participates in benzoate degradation via hydroxylation and uses flavin adenine dinucleotide as a cofactor.
=== Street confrontations === As the hours passed many more people took to the streets. Soon the protesters—unarmed and unorganised—were confronted by soldiers, tanks, APCs, USLA troops (Unitatea Specială pentru Lupta Antiteroristă, anti-terrorist special squads) and armed plainclothes Securitate officers. The crowd was soon being shot at from various buildings, side streets and tanks. There were many casualties, including deaths, as victims were shot, clubbed to death, stabbed and crushed by armoured vehicles. One APC drove into the crowd around the InterContinental Hotel, crushing people. Physician Florin Filipoiu, who took part in the protests at the InterContinental, declared in a 2010 interview that "it was only an illusion that the Army was on the revolutionaries' side." A French journalist, Jean-Louis Calderon, was killed. A street near University Square was later named after him, as well as a high school in Timișoara. Belgian journalist Danny Huwé was shot and killed on 23 or 24 December 1989.
Sources: en.wikipedia.org
=== 26 July === The Leadership Council of the Sudan Founding Alliance (TASIS), a coalition led by the RSF, announced a parallel government with Hemedti as chair of a 15-person presidential council and Mohammed Hassan Osman al-Ta'ishi as prime minister.
== Predictive value == Murphy's sign has a high sensitivity and negative predictive value, although the specificity is not high. However, in the elderly the sensitivity is markedly lower; a negative Murphy's sign in an elderly person is not useful for ruling out cholecystitis if other tests and the clinical history suggest the diagnosis.
==== United States ==== Under federal United States law, phenazepam is not currently classified as a controlled substance, as the Federal Analog Act only provides for automatic assumed classification of chemicals "substantially similar" to existing Schedule I or Schedule II drugs, whereas all controlled benzodiazepines under the Controlled Substances Act are classified as Schedule IV. Although phenazepam is currently not controlled, sale for human use remains illegal in the United States. Suppliers attempt to circumvent this regulation by placing a "Not for human use" disclaimer on the product's label. Individual states in the United States often ban these analog drugs by name as they appear. Since 2012, Louisiana has classified phenazepam as a controlled dangerous substance. This ban affects several products, some of which were sold at retail stores under the guise of air freshener or similar, containing phenazepam yet claiming not to be for human use. This legislation was introduced after one such product, branded as "Zannie" and marketed as an air freshener rapidly gained publicity as the subject of numerous media reports, attracting the attention of officials. The ensuing investigation effort, led by Senator Fred Mills and Louisiana Poison Center Director Mark Ryan, positively identified the active ingredient of "Zannie" as phenazepam. According to Ryan, chemical analysis identified the active ingredient as "100 percent phenazepam".
=== Self-assembly === Self-assembly methods have been shown to be promising methods for tissue engineering. Self-assembly methods have the advantage of allowing tissues to develop their own extracellular matrix, resulting in tissue that better recapitulates biochemical and biomechanical properties of native tissue. Self-assembling engineered articular cartilage was introduced by Jerry Hu and Kyriacos A. Athanasiou in 2006 and applications of the process have resulted in engineered cartilage approaching the strength of native tissue. Self-assembly is a prime technology to get cells grown in a lab to assemble into three-dimensional shapes. To break down tissues into cells, researchers first have to dissolve the extracellular matrix that normally binds them together. Once cells are isolated, they must form the complex structures that make up our natural tissues.
Sources: en.wikipedia.org
Legal status varies by country, but cardarine is not approved as a medicine in major jurisdictions. It is often sold as a research chemical, a category that may not be lawful for human use. Buyers should check local laws and product labels carefully.
Anti-doping laboratories use LC-MS/MS to detect GW501516 and its metabolites, usually in urine. The method can identify the parent compound at low concentrations. Detection windows vary with dose and individual factors.
No, cardarine has no approved medical uses in major jurisdictions. Early research explored metabolic conditions, but those programs were discontinued. It is not a registered treatment for any disease.
No. Cardarine is GW501516, a PPARδ agonist, while SARMs act on androgen receptors. The two classes are often grouped in informal discussions despite different mechanisms.