LC-MS/MS is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-06-20. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
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.
| 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 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.
Preclinical research reported that GW501516 increased running endurance in mice and improved lipid profiles in some animal species. Early human trials explored effects on high-density lipoprotein cholesterol, triglycerides, and glucose handling, but the program was discontinued. Published human data are sparse and do not establish efficacy for any condition. Studies also examined PPAR delta in cancer biology, with conflicting findings across models. The relationship between receptor activation, tissue context, and disease risk remains an active area of investigation.
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
Cardarine is a common name for GW501516, a synthetic compound studied for its effects on lipid and glucose metabolism. It functions as an agonist at peroxisome proliferator-activated receptor delta, or PPARδ, a nuclear receptor that influences gene expression. The molecule is not a steroid, nor is it a selective androgen receptor modulator. It is also known in research and sports literature as GW-501516 and endurobol. Early laboratory work examined its metabolic activity in cell cultures and animal models.
=== Metabolic niche partitioning === In 2010, exometabolomics analysis of the cyanobacterium, Synechococcus sp. PCC 7002 by Baran, et al. revealed that this photoautotroph could deplete a diverse pool of exogenous metabolites. A follow-up exometabolomics study on sympatric microbial isolates from biological soil crust, which exist in communities with cyanobacteria in the desert soils of the Colorado Plateau, suggested that metabolite niche partitioning exists in these communities, where each isolate only utilizes 13-26% of metabolites from the soil
In bioinformatics and evolutionary biology, a substitution matrix describes the frequency at which a character in a nucleotide sequence or a protein sequence changes to other character states over evolutionary time. The information is often in the form of log odds of finding two specific character states aligned and depends on the assumed number of evolutionary changes or sequence dissimilarity between compared sequences. It is an application of a stochastic matrix. Substitution matrices are usually seen in the context of amino acid or DNA sequence alignments, where they are used to calculate similarity scores between the aligned sequences.
On 2 August 2015, The FA Community Shield in England was broadcast in Ultra HD by broadcast company BT Sport, becoming the first live football game shown in Ultra HD on the world's first commercial Ultra HD channel. The match was shown on Europe's first Ultra HD channel, BT Sport Ultra HD where selected live English Premier League and European Champions League matches were broadcast. Fashion One 4K launched on 2 September 2015 becoming the first global Ultra HD TV channel. Reaching nearly 370 million households across the world, the fashion, lifestyle and entertainment network broadcasts via satellite from Measat at 91.5°E (for Asia Pacific, Middle East, Australia) and from SES satellites Astra 19.2°E (for Europe), SES-3 at 103°W (for North America), NSS-806 at 47.5°W (for South America). In September 2015, Eutelsat presented new consumer research, conducted by TNS and GfK, on Ultra HD and screen sales in key TV markets. The study looked at consumer exposure to Ultra HD, perceived benefits and willingness to invest in equipment and content. GfK predicts a 200% increase in Ultra HD screen sales from June to December 2015, with sales expected to reach five million by the end of the year. GfK also forecasts that Ultra HD screens in 2020 will represent more than 70% of total sales across Europe and almost 60% in the Middle East and North Africa. On 2 September 2015, Sony unveiled the Xperia Z5 Premium; the first smartphone with a 4K display. On 9 September 2015, Apple Inc. announced that their new smartphone the iPhone 6S could record video in 4K.
Hydrophobins are a group of small (~100 amino acids) cysteine-rich proteins that were discovered in filamentous fungi that are lichenized or not. Later similar proteins were also found in Bacteria. Hydrophobins are known for their ability to form a hydrophobic (water-repellent) coating on the surface of an object. They were first discovered and separated in Schizophyllum commune in 1991. Based on differences in hydropathy patterns and biophysical properties, they can be divided into two categories: class I and class II. Hydrophobins can self-assemble into a monolayer on hydrophilic:hydrophobic interfaces such as a water:air interface. Class I monolayer contains the same core structure as amyloid fibrils, and is positive to Congo red and thioflavin T. The monolayer formed by class I hydrophobins has a highly ordered structure, and can only be dissociated by concentrated trifluoroacetate or formic acid. Monolayer assembly involves large structural rearrangements with respect to the monomer. Fungi make complex aerial structures and spores even in aqueous environments. Hydrophobins have been identified in lichens as well as non-lichenized ascomycetes and basidiomycetes; whether they exist in other groups is not known. Hydrophobins are generally found on the outer surface of conidia and of the hyphal wall, and may be involved in mediating contact and communication between the fungus and its environment. Some family members contain multiple copies of the domain.
Sources: en.wikipedia.org
Narrated by Stephen Rashbrook, produced by Nick Catliff, directed by Henry Singer, made by Lion Television and Sandpaper Films. Shown on Monday 7 February 2000 on The Nature of Things in Canada 27 September Near Miss, about ATC, the 1960 New York mid-air collision in December 1960; around 7,500 aircraft visit the three airports each day; LaGuardia Airport has two conjoined runways that operate in a strange mixed way; on 3 April 1998 there was a near miss; USAir Flight 5050 in September 1989; Colombian Avianca Flight 52 in January 1990 approached John F. Kennedy International Airport when running out of fuel, when a 4-hour flight turned into 6 hours due to weather. Narrated by Jack Davenport, directed by Jeremy Llewellyn-Jones, produced by Emma Bowman, made by Windfall Films and The Learning Channel (TLC). On All 4 4 October Curing the Incurable, the strange teratoma cells; Paul R. Sanberg of the University of South Florida; Irving Weissman of Stanford University; pathologist John Goepel; Peter Andrews (biologist); neurosurgeon Douglas Kondziolka of the University of Pittsburgh Medical Center, and stereotactic surgery; John Sinden of ReNeuron; Ann Tsukamoto of CytoTherapeutics. Narrated by David Malone, made by Boa Picture Company 20 December Talking with Aliens, an Equinox Special, with zoologist Denise L. Herzing, made by Pioneer Films
Cyclotides have been reported to have a wide range of biological activities, including anti-HIV, insecticidal, anti-tumour, antifouling, anti-microbial, hemolytic, neurotensin antagonism, trypsin inhibition, and uterotonic activities. An ability to induce uterine contractions was what prompted the initial discovery of kalata B1. The potent insecticidal activity of cyclotides kalata B1 and kalata B2 has prompted the belief that cyclotides act as plant host-defence agents. The observations that dozens or more cyclotides may be present in a single plant and the cyclotide architecture comprises a conserved core onto which a series of hypervariable loops is displayed suggest that cyclotides may be able to target many pests/pathogens simultaneously.
The linea alba (Latin for: white line) is a fibrous midline structure of the anterior abdominal wall situated between the two recti abdominis muscles (one on either side). The umbilicus (navel) is present on the linea alba through which foetal umbilical vessels pass before birth. The linea alba is formed by the union of aponeuroses (of the muscles of the anterior abdominal wall) that collectively make up the rectus sheath. The linea alba attaches to the xiphoid process superiorly, and to the pubic symphysis inferiorly. It is narrow inferiorly where the two recti abdominis muscles are in contact with each other posterior to it, and broadens superior-ward from just inferior to the umbilicus. The name means white line as it is composed mostly of collagen connective tissue, which has a white appearance.
In New Zealand, it was applied to the kawakawa (Piper excelsum), which is endemic to New Zealand and nearby Norfolk Island and Lord Howe Island. It was exploited by the Māori based on previous knowledge of the kava, as the latter could not survive in the colder climates of New Zealand. The Māori name for the plant, kawakawa, is derived from the same etymon as kava, but reduplicated. It is a sacred tree among the Māori people. It is seen as a symbol of death, corresponding to the rangiora (Brachyglottis repanda), which is the symbol of life. However, kawakawa has no psychoactive properties. Its connection to kava is linked to its similarity in appearance and bitter taste. Other names for kava include ʻawa (Hawaii), ʻava (Samoa), yaqona or yagona (Fiji), sakau (Pohnpei), seka (Kosrae), and malok or malogu (parts of Vanuatu).
Acellular dermis is a type of biomaterial derived from processing human or animal tissues to remove cells and retain portions of the extracellular matrix (ECM). These materials are typically cell-free, distinguishing them from classical allografts and xenografts, can be integrated or incorporated into the body, and have been FDA approved for human use for more than 10 years in a wide range of clinical indications.
Sources: en.wikipedia.org
== Standard structure == The amino acids in a standard π-helix are arranged in a right-handed helical structure. Each amino acid corresponds to an 87° turn in the helix (i.e., the helix has 4.1 residues per turn), and a translation of 1.15 Å (0.115 nm) along the helical axis. Most importantly, the N-H group of an amino acid forms a hydrogen bond with the C=O group of the amino acid five residues earlier; this repeated i + 5 → i hydrogen bonding defines a π-helix. Similar structures include the 310 helix (i + 3 → i hydrogen bonding) and the α-helix (i + 4 → i hydrogen bonding).
The service-entry deadline of summer 1980, announced by Minister of Civil Aviation Boris Bugayev in 1977 had passed, however, and the Il-86 missed the Moscow Olympics in the summer of 1980. Overall development of the Il-86 occupied over a decade. The length of this period was due to the sensitivity of the airliner's configuration, problems with its powerplant, prolonged avionics development and the low priority of civil as opposed to military aircraft. In its earlier stages, the Il-86 programme was also held back by hopes of US airliner imports. Certificating the Il-86 to the very demanding set of Soviet and Comecon standards called NLGS-2 also delayed progress; it was the first Soviet aircraft to undergo a full certification programme since certification was introduced in the USSR in 1967 and became mandatory five years later.
In some cases vaccines may result in partial immune protection (in which immunity is less than 100% effective but still reduces risk of infection) or in temporary immune protection (in which immunity wanes over time) rather than full or permanent immunity. They can still raise the reinfection threshold for the population as a whole and make a substantial impact. They can also mitigate the severity of infection, resulting in a lower mortality rate, lower morbidity, faster recovery from illness, and a wide range of other effects. Those who are older often display less of a response than those who are younger, a pattern known as Immunosenescence. Adjuvants commonly are used to boost immune response, particularly for older people whose immune response to a simple vaccine may have weakened. The efficacy or performance of the vaccine is dependent on several factors:
=== Sample preparation === Conducting and semi-conducting samples may be directly analyzed after being formed into electrodes. Non-conductive samples are first powdered, mixed with a conducting powder (usually high purity graphite or silver), homogenized, and then formed into electrodes. Even liquids can be analyzed if they are frozen or after impregnating a conducting powder. Sample homogeneity is important for reproducibility.
Other alien species depicted include antlions, human-sized burrowing insectoids; bullsquids, acid-shooting tentacled predators; and barnacles, ceiling-dwelling amorphous creatures who capture others with their sticky tongue. The series' main recurring symbol is the Greek lambda. It first appears in Half-Life on Freeman's HEV suit and as the namesake of the Lambda Complex responsible for teleporting Freeman to Xen to shut the portal. It reappears in Half-Life 2 as the symbol of the anti-Combine resistance.
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.
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.