This is a working overview of LC-MS/MS, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-08-14. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| 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. |
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.
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.
PPARδ is a nuclear receptor that influences transcription of genes involved in fatty acid oxidation, lipid transport, and energy homeostasis. GW501516 binds and activates this receptor with high selectivity relative to PPARα and PPARγ in laboratory assays. Activation alters expression of target genes in skeletal muscle, liver, and adipose tissue in animal models. The exact clinical consequences of these changes in humans remain incompletely characterized, and observed effects in animals do not establish therapeutic benefit or safety.
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 the investigational chemical GW501516, also written GW-1516. It was developed as a peroxisome proliferator-activated receptor delta agonist for metabolic conditions such as dyslipidemia. Early research focused on lipid handling and energy use in skeletal muscle and other tissues. The compound was never approved as a medicine. In public discussion, it is often grouped with performance-enhancing substances, although its receptor target differs from that of anabolic steroids or selective androgen receptor modulators. Regulatory and health authorities have issued warnings about its use.
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.
== Mechanism == The total protein concentration is readout by an increase in absorbance at 565 nm, which can then be measured using colorimetric techniques, including using microplate readers. Most common reagents, except thiols and SDS, are compatible with the assay. An optimized formulation for the assay to maximize sensitivity in microplate format was described.
1581), mushrooms were eaten in festivities conducted on the occasion of Aztec emperor Moctezuma II's accession to the throne in 1502. The Franciscan friar Bernardino de Sahagún wrote of witnessing mushroom use in the Florentine Codex (published 1545–1590), saying that some merchants celebrated upon returning from a successful business trip by consuming mushrooms to evoke revelatory visions. After the defeat of the Aztecs, the Spanish forbade traditional religious practices and rituals they considered "pagan idolatry", including ceremonial mushroom use. For the next four centuries, the Indians of Mesoamerica hid their use of entheogens from the Spanish authorities. Dozens of species of psychedelic mushrooms are found in Europe, but there is little documented usage of them in Old World history besides the use of Amanita muscaria among Siberian peoples. The few existing accounts that mention psilocybin mushrooms typically lack sufficient information to allow species identification, focusing on their effects. For example, Flemish botanist Carolus Clusius (1526–1609) described the bolond gomba ("crazy mushroom"), used in rural Hungary to prepare love potions. English botanist John Parkinson included details about a "foolish mushroom" in his 1640 herbal Theatricum Botanicum. The first reliably documented report of intoxication with Psilocybe semilanceata—Europe's most common and widespread psychedelic mushroom—involved a British family in 1799, who prepared a meal with mushrooms they had picked in London's Green Park.
Cysteine proteases, also known as thiol proteases, are hydrolase enzymes that degrade proteins. These proteases share a common catalytic mechanism that involves a nucleophilic cysteine thiol in a catalytic triad or dyad. Discovered by Gopal Chunder Roy in 1873, the first cysteine protease to be isolated and characterized was papain, obtained from Carica papaya. Cysteine proteases are commonly encountered in fruits including the papaya, pineapple, fig, and kiwifruit. The proportion of protease tends to be higher when the fruit is unripe. In fact, the latex of dozens of different plant families are known to contain cysteine proteases. Cysteine proteases are used as an ingredient in meat tenderizers.
Sources: en.wikipedia.org
== Clinical significance == Disorders of capillary formation as a developmental defect or acquired disorder are a feature in many common and serious disorders. Within a wide range of cellular factors and cytokines, issues with normal genetic expression and bioactivity of the vascular growth and permeability factor vascular endothelial growth factor (VEGF) appear to play a major role in many of the disorders. Cellular factors include reduced number and function of bone-marrow derived endothelial progenitor cells. and reduced ability of those cells to form blood vessels.
=== Fluorene dyes === Fluorene dyes are well developed. Most are prepared by condensation of the active methylene group with carbonyls. 2-Aminofluorene, 3,6-bis(dimethylamino)fluorene, and 2,7-diiodofluorene are precursors to dyes.
Microbats and a few megabats emit ultrasonic sounds to produce echoes. The sound intensity of these echoes is dependent on subglottic pressure. The bats' cricothyroid muscle, located inside the larynx, controls the orientation pulse frequency, which is an important function. By comparing the outgoing pulse with the returning echoes, bats can learn about their environment and detect prey in darkness. Some bat calls can reach over 140 decibels. Microbats use their larynx to emit echolocation signals through the mouth or the nose. Bat call frequencies range from as low as 11 kHz to as high as 212 kHz. The noses of various groups of bats have fleshy extensions, known as nose-leaves, which play a role in sound transmission. In low-duty cycle echolocation, bats can separate their calls and returning echoes by time. They have to time their short calls to finish before echoes return. In high-duty cycle echolocation, bats emit a continuous call and separate pulse and echo in frequency using the Doppler effect of their motion in flight. The shift of the returning echoes yields information relating to the motion and location of the bat's prey. These bats must deal with changes in the Doppler shift due to changes in their flight speed. They have adapted to change their pulse emission frequency in relation to their flight speed so echoes still return in the optimal hearing range. In addition to echolocating prey, bat ears are sensitive to sounds made by their prey, such as the fluttering of moth wings.
Sources: en.wikipedia.org
=== Trade war === Political scientist Hilmar Mjelde called Trump's actions a "political own goal of historic proportions", and said he believes Trump has underestimated European steadfastness. Annie Genevard said the EU has strong leverage and can retaliate in a trade war with the US, and that it could be "deadly for the United States", emphasising that Europeans will not let the US do as it pleases.
The fiber angle (the angle the fiber makes with the long axis of the body) plays a critical role in torsion, if the angle is greater than 54°44', during muscle contraction, torsion and elongation will occur. If the fiber angle is less than 54°44', torsion and shortening will occur.
== Isomers == Several isomers of Fumonisin B4 have been detected. A larger group is the partially hydrolysed form, denoted as PHFB4, which has been detected using HPLC-ITMS. Another significant isomer is the 3-epi-FB4, which has been identified using NMR, it has also been shown that this isomer occur 10-40% of the regular FB4 sample in nature.
On October 10, 1868, Carlos Manuel de Céspedes freed his slaves and declared revolution against Spain at the Cry of Yara. de Céspedes was also the Worshipful Master of Logia Buena Fe (English: Good Faith Lodge) at Manzanillo, a Lodge within GOCA. Around this time, the first "non white" Cubans were initiated as Freemasons into the revolutionary Masonic Lodges. The Colonial government saw the Freemasonry movement in Cuba as inherently associated with the revolutionary movement. They feared that gatherings of Freemasons could be used as cover for the revolutionary cause, and went on a renewed campaign to fully suppress Freemasonry in the colony. On the same day that the war was declared, GOCA was dissolved in Havana. Many of the revolutionaries who signed the Guáimaro Constitution were also Freemasons. However, almost all of the revolutionary Freemasons during this war were former members of GOCA, as in the beginning of this war, the Colon Freemasons were largely supportive of Spanish rule. With the dissolution of GOCA, its former members founded individual Lodges during the war. Famously, Carlos Manuel de Céspedes established the Independence Lodge. Tínima Lodge and Camagüey Lodge were also created around this time. The Grand Lodge of Colon was absorbed by the Supreme Council in Santiago de Cuba, but it could no longer operate at full capacity, and could not rely on spiritual support from abroad. Spanish spies were monitoring traffic from the United States.
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.
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.