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.
Last reviewed on 2026-03-04. Where a claim depends on a specific study, the study is described rather than over-claimed.
Clinical development stopped after rodent studies showed tumors at multiple sites. Whether those findings predict human cancer risk remains an open question, but they led sponsors to discontinue programs. Human safety data are limited to small, short-term studies that were not designed to assess cancer risk. Reported effects in those studies included changes in blood lipids, but the evidence is insufficient for medical use. Long-term consequences of nonmedical use are not well characterized. Questions about dose, duration, and individual susceptibility remain unresolved.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | GW501516; GW-1516; endurobol | GW501516 is the research code |
| Drug class | PPARδ agonist | Not a selective androgen receptor modulator |
| Molecular formula | C21H18F3NO3S2 | Established chemical formula |
| Molar mass | 453.5 g/mol | Calculated from the formula |
| Regulatory status | Prohibited in sport; not approved as medicine | Status varies by country |
Cardarine is explicitly prohibited by the World Anti-Doping Agency under the class of PPARδ agonists. Its presence in urine or blood samples can be detected using mass spectrometry-based methods, often liquid chromatography-tandem mass spectrometry. Athletes who test positive may face sanctions, including bans from competition. The compound is also regulated as a prescription-only or unapproved drug in many countries. Enforcement varies by jurisdiction, and some regions treat it as a controlled substance. Online sales may occur despite these restrictions, creating quality and legal risks.
Laboratory detection of cardarine typically involves sample preparation followed by chromatographic separation and mass spectrometric identification. Urine is the most common matrix for anti-doping tests, though blood and hair have also been explored. Methods can target the parent compound or its metabolites, depending on the expected window of detection. Reference standards are required for accurate quantification. Matrix effects and dilution can influence results, so laboratories use internal standards and validation protocols. The exact detection window varies with dose, route, and individual metabolism.
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 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.
=== Ultrasound === Hepatomegaly is consistently identified with an abdominal ultrasound; however, it is also commonly found in diabetic cats without hypersomatotropism. Other findings from an abdominal ultrasound include: renomegaly, pelvic dilation, an enlarged pancreas, splenomegaly and bilateral adrenomegaly. The size of the adrenal glands can be useful in diagnosis, studies have found that the size of the adrenal gland in diabetic cats without hypersomatotropism does not differ significantly from non-diabetic cats; however, adrenomegaly is not pathognomonic to hypersomatotropism and can occur with other conditions in cats such as pituitary-dependent hypercortisolism.
In late 2025, Hollister Co. partnered with Taco Bell for a limited-edition, Y2K-inspired capsule collection. The drop, the first Hollister × Taco Bell collaboration, includes 11 pieces: vintage-style graphic tees, baggy denim, soft “Feel Good Fleece” hoodies and sweatpants, cozy socks, and a hot-sauce packet keychain accessory. The collection officially launched in Hollister stores and online on December 1, 2025, with prices ranging from US $14.95 to US $79.95, and sizes offered from XS to XL.
Normally, the stereochemistry of the alkene is retained throughout the reaction, except under harsh reaction conditions. A variety of alkenes may be used, and these include both α- and β-halo-α,β unsaturated ketones, esters, and sulfoxides (which normally need a copper (I) additive to proceed), and more (see example below). Vinyl triflates are also sometimes used. Some reactions require the addition of LiCl and others are slowed down, implying that two mechanistic pathways are present.
The original game left her in a deserted parking lot after destroying GLaDOS, but the update involved Chell being dragged back into the facility by a "Party Escort Bot". Though Portal 2 was originally announced for a Q4 2010 release, the game was released on April 19, 2011. A modding community has developed around Portal, with users creating their own test chambers and other in-game modifications. The group "We Create Stuff" created an Adobe Flash version of Portal, titled Portal: The Flash Version, just before release of The Orange Box. This flash version was well received by the community and the group has since converted it to a map pack for the published game. Another mod, Portal: Prelude, is an unofficial prequel developed by an independent team of three that focuses on the pre-GLaDOS era of Aperture Science, and contains nineteen additional "crafty and challenging" test chambers. An ASCII version of Portal was created by Joe Larson. An unofficial port of Portal to the iPhone using the Unity game engine was created but only consisted of a single room from the game. Mari0 is a fan-made four-player coop mashup of the original Super Mario Bros. and Portal. An unofficial port for the Nintendo 64 console titled Portal 64 was under development by James Lambert. By September 2023, he had a working copy but still had ways to go to be completely finished. The project was taken down in January 2024 due to a request by Valve; according to Lambert, the port's reliance on "Nintendo's proprietary libraries" was the reason.
Sources: en.wikipedia.org
==== Reliable prediction of T-cell epitopes ==== A novel input representation has been developed consisting of a combination of sparse encoding, Blosum encoding, and input derived from hidden Markov models. This method predicts T-cell epitopes for the genome of hepatitis C virus and discuss possible applications of the prediction method to guide the process of rational vaccine design.
In physiology, capillary action is essential for the drainage of continuously produced tear fluid from the eye. Two canaliculi of tiny diameter are present in the inner corner of the eyelid, also called the lacrimal ducts; their openings can be seen with the naked eye within the lacrymal sacs when the eyelids are everted. Paper towels absorb liquid through capillary action, allowing a fluid to be transferred from a surface to the towel. The small pores of a sponge act as small capillaries, causing it to absorb a large amount of fluid. Some textile fabrics are said to use capillary action to "wick" sweat away from the skin. These are often referred to as wicking fabrics, after the capillary properties of candle and lamp wicks. Capillary action is observed in thin layer chromatography, in which a solvent moves vertically up a plate via capillary action. In this case the pores are gaps between very small particles. Capillary action draws ink to the tips of fountain pen nibs from a reservoir or cartridge inside the pen. With some pairs of materials, such as mercury and glass, the intermolecular forces within the liquid exceed those between the solid and the liquid, so a convex meniscus forms and capillary action works in reverse. In hydrology, capillary action describes the attraction of water molecules to soil particles. Capillary action is responsible for moving groundwater from wet areas of the soil to dry areas. Differences in soil potential (
Neuropeptide FF group Neuropeptide AF Neuropeptide FF Neuropeptide SF (RFRP-1) Neuropeptide VF (RFRP-3) (GnIH - avian species) Prolactin-releasing peptide (PrRP) Pyroglutamylated RFamide peptide (QRFP) Kisspeptin (disputed)
Sources: en.wikipedia.org
=== Saturable absorption === Graphene exhibits unique saturable absorption, which saturates when the input optical intensity exceeds a threshold value. This nonlinear optical behavior, termed saturable absorption, occurs across the visible to near-infrared spectrum, due to graphene's universal optical absorption and zero band gap. This property has enabled full-band mode-locking in fiber lasers using graphene-based saturable absorbers, contributing significantly to ultrafast photonics. Additionally, the optical response of graphene/graphene oxide layers can be electrically tuned. Saturable absorption in graphene could occur at the Microwave and Terahertz band, owing to its wideband optical absorption property. The microwave-saturable absorption in graphene demonstrates the possibility of graphene microwaves and terahertz photonics devices, such as a microwave-saturable absorber, modulator, polarizer, microwave signal processing, and broadband wireless access networks.
=== Diagnostic use === CRP is used mainly as an inflammation marker. Apart from liver failure, there are few known factors that interfere with CRP production. Interferon alpha inhibits CRP production from liver cells which may explain the relatively low levels of CRP found during viral infections compared to bacterial infections Measuring and charting CRP values can prove useful in determining disease progress or the effectiveness of treatments. ELISA and radial immunodiffusion methods are available for research use, while immunoturbidimetry is used clinically for CRP and nephelometry is typically used for hsCRP. Cutoffs for cardiovascular risk assessment have included:
== Notable achievements and awards == In 1996, Kessler became a member of the Bavarian Academy of Sciences and Humanities, one of the eight state academies in Germany. In 2002, he was elected to membership of the Academy of Sciences Leopoldina, the national academy of Germany.
== Gene == In humans, COL21A1 is located on the short arm of chromosome 6 at band 6p12.3–p11.2. The gene spans approximately 337 kb of genomic DNA and contains 31 exons; its 5′-untranslated exons (exon 1 and exon 1a) are alternatively spliced, and alternative splicing of the gene gives rise to multiple transcript variants. The exon–domain organization of COL21A1 resembles that of other genes encoding FACIT collagens.
Sources: en.wikipedia.org
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.
No. It has no approved medical indication in any country. Regulatory agencies have not cleared it for treatment or prevention of any condition.
Early clinical work stopped after rodent carcinogenicity findings. Those animal results raised concerns about long-term human risk, although direct human evidence is lacking. The human relevance of the tumors remains an open scientific question.
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.