This is a working overview of preclinical models, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-08-03. Anything still debated is marked as such rather than presented as settled.
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.
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.
GW501516 acts as a selective agonist at PPARδ, a nuclear receptor that regulates transcription of genes involved in lipid handling and energy metabolism. Activation of PPARδ in preclinical models increases fatty acid oxidation, mitochondrial biogenesis, and exercise endurance in rodents. These effects have made the compound a subject of metabolic research and also a target for sport anti-doping rules. In humans, however, controlled studies are limited, and whether similar endurance or metabolic changes occur at tolerated exposures remains an open question. The receptor’s broad tissue distribution also means downstream effects may vary by organ and condition.
Detection of GW501516 in biological samples generally relies on liquid chromatography coupled with tandem mass spectrometry. Urine is a common matrix in anti-doping analysis, while blood or plasma may be used in research settings. Sample preparation can involve enzymatic hydrolysis, protein precipitation, or solid-phase extraction before instrumental analysis. Because the compound undergoes metabolism, assays may target the parent molecule, one or more metabolites, or both. Detection windows are not fixed; they depend on factors such as dose, route, individual metabolism, and assay sensitivity. Reference standards are required for accurate identification and quantification.
Handling and quality assessment of cardarine reference material follow general laboratory practices for poorly characterized compounds. It typically appears as a white to off-white powder and is sparingly soluble in water but soluble in organic solvents such as dimethyl sulfoxide and ethanol. Storage recommendations usually specify a cool, dry, dark place, with long-term storage at low temperature and desiccation. Purity may be checked by high-performance liquid chromatography with ultraviolet detection, while identity is confirmed by mass spectrometry and nuclear magnetic resonance. No pharmacopeial monograph exists, so reported purity and stability depend on the supplier’s methods.
| 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 |
Laboratory studies have examined GW501516 in cell cultures and rodents for conditions such as dyslipidemia, insulin resistance, and obesity. Some trials in humans were initiated, but development was discontinued after preclinical findings raised concerns about cancer in certain models. Those findings do not prove that the compound causes cancer in people, but they contributed to regulatory caution. Later reviews often describe the evidence as preliminary and insufficient for assessing long-term safety.
In the fitness and bodybuilding literature, cardarine is frequently discussed as an endurance agent or fat-loss compound, although such claims are not supported by robust clinical evidence. Online descriptions often mix animal data, user anecdotes, and marketing language. Researchers who study PPARδ agonists distinguish between receptor activation in controlled experiments and unsupervised use of unverified products. The latter introduces unknown purity, dose, and interactions, making reported experiences difficult to interpret scientifically.
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.
In ambient ionization, the formation of ions occurs outside the mass spectrometer without sample preparation. Electrospray is used for ion formation in a number of ambient ion sources. Desorption electrospray ionization (DESI) is an ambient ionization technique in which a solvent electrospray is directed at a sample. The electrospray is attracted to the surface by applying a voltage to the sample. Sample compounds are extracted into the solvent which is again aerosolized as highly charged droplets that evaporate to form highly charged ions. After ionization, the ions enter the atmospheric pressure interface of the mass spectrometer. DESI allows for ambient ionization of samples at atmospheric pressure, with little sample preparation.
== Function == The main function of motilin is to increase the migrating myoelectric complex component of gastrointestinal motility and stimulate the production of pepsin. Motilin is also called "housekeeper of the gut" because it improves peristalsis in the small intestine and clears out the gut to prepare for the next meal. A high level of motilin secreted between meals into the blood stimulates the contraction of the fundus and antrum and accelerates gastric emptying. It then contracts the gallbladder and increases the squeeze pressure of the lower esophageal sphincter. Other functions of motilin include increasing the release of pancreatic polypeptide and somatostatin.
An extended-release formulation of low-dose oral minoxidil is under development for treatment of hair loss. It is being developed by Veradermics under the developmental code name VDPHL01. As of September 2025, it is in phase 3 clinical trials for this indication. A low-dose sublingual formulation of minoxidil is under development for treatment of hair loss. It is being developed by Samson Clinical. As of September 2025, it is in phase 3 clinical trials for this indication. The pharmacokinetics of this formulation are being studied. Finasteride/latanoprost/minoxidil (developmental code name TH-07 or TH07; Triple Hair) is a topical combination drug including minoxidil, finasteride, and latanoprost which is under development for the treatment of hair loss. As of December 2023, it is in phase 2 clinical trials for this indication. AB-103 is a minoxidil sulfotransferase stimulant which enhances minoxidil conversion into its active form minoxidil sulfate in hair follicles and is under development as a topical medication for the treatment of hair loss. Sulfotransferase activity in hair follicles has been associated with minoxidil's clinical effectiveness. As of February 2024, AB-103 is in phase 3 clinical trials for this indication, although there have been no new updates since 2019.
Sources: en.wikipedia.org
Trump is the first president since Grover Cleveland in 1892 to win non-consecutive terms. 2024 also marked the first time since 1892 that the incumbent party had lost in each of three consecutive presidential elections. This was the first time since 1980 that the Democrats were voted out after a single four-year term. This was also the second consecutive election in which the incumbent party had lost after a single four-year term. Trump is the first Republican to win the popular vote since George W. Bush's election in 2004; Bush and Trump are also the only two presidents who won the Electoral College while losing the popular vote in one election who then went on to win both the Electoral College and the popular vote in a subsequent election. Trump is also the first non-incumbent Republican to have won the popular vote since George H. W. Bush in 1988. Trump won a 1.48% margin of victory. While winning the popular vote, Trump did not win a majority of the popular vote; he is the first winning presidential candidate since Bill Clinton in 1996 to win the popular vote with a plurality and also the first Republican since Richard Nixon in 1968 to do so. After Cleveland in 1884 and 1892, Woodrow Wilson in 1912 and 1916, and Clinton in 1992 and 1996, Trump became the fourth president since 1880 to win two presidential elections and receive less than 50% of the popular vote in both presidential election victories. Trump is the first presidential candidate since Barack Obama in 2012 to win a second term in the White House and also the first Republican since George W.
Knoll Pharmaceuticals was a drug development company founded by Albert Knoll and Hans Knoll in Germany in 1886. The company was taken over by German BASF in 1975, which sold it to Abbott Laboratories on 30 June 2002 for $6.9 billion. It was the developer of several drugs: Dilaudid (hydromorphone), a powerful and very water-soluble narcotic analgesic (Betäubungsmittel) introduced in 1926, as small oral tablets of a number of strengths, multipurpose (hypodermic) tablets, compounding powder, ampoules of solution for injection, and dry ampoules for reconstitution. Knoll also produced somewhat similar hydrocodone tablets named Dicodid; this drug which compares to codeine as hydromorphone compares to morphine was first synthesised and announced in Germany in 1920. The obverse sides of the oral tablets bear a stylised letter "K" and the reverse has the relevant imprint code for the medication in the locale of sale and/or number of milligrams of hydromorphone. Sibutramine, a serotonin-norepinephrine reuptake inhibitor, prescribed as an adjunct in the treatment of exogenous obesity, marketed by Abbott but withdrawn from the market in the United States and most other countries in 2010 Propafenone, an antiarrhythmic agent, marketed by Abbott. Isophan, a slightly modified version of the methamphetamine drug Pervitin, which the Nazi government in 1940 distributed to the German army and air force in an effort to win WW2.
=== Research === A major thread of Bumpus' research is determining how antiviral drugs used to treat HIV-1 are metabolized and how genetic variations in drug-processing enzymes may impact these drugs' efficacy. One antiviral commonly used to treat and prevent HIV is tenofovir (Viread). Tenofovir is a nucleotide analog reverse transcriptase inhibitor that prevents the HIV virus from replicating. Tenofovir is given in an inactive form – it has to be phosphorylated twice to become active, and this phosphorylation is carried out in two steps by separate kinases. Bumpus and her team identified which kinases do this and found that the enzymes responsible varied by cell type, so administration route (e.g. orally or topically) could affect how effectively the drug is processed. They also sequenced the genes of these kinases from different patients and found that some people have genetic variants in the kinases that may affect how effectively the drug is processed. Tenofovir can be given prophylactically, and Bumpus collaborated with researchers from around the world in a study of the use of tenofovir for HIV pre-exposure prophylaxis (PrEP) to prevent HIV infection in heterosexual men and women. Bumpus has also researched nonnucleoside reverse transcriptase inhibitors. Her lab was the first to publish the P450-catalyzed phase 1 and phase 2 metabolic pathways of two nonnucleoside reverse transcriptase inhibitors, rilpivirine and etravirine and was first to characterize the metabolism of the nonnucleoside reverse transcriptase inhibitor dapivirine.
== History == The first low-cost spectrophotometer capable of recording an infrared spectrum was the Perkin-Elmer Infracord produced in 1957. This instrument covered the wavelength range from 2.5 μm to 15 μm (wavenumber range 4,000 cm−1 to 660 cm−1). The lower wavelength limit was chosen to encompass the highest known vibration frequency due to a fundamental molecular vibration. The upper limit was imposed by the fact that the dispersing element was a prism made from a single crystal of rock-salt (sodium chloride), which becomes opaque at wavelengths longer than about 15 μm; this spectral region became known as the rock-salt region. Later instruments used potassium bromide prisms to extend the range to 25 μm (400 cm−1) and caesium iodide 50 μm (200 cm−1). The region beyond 50 μm (200 cm−1) became known as the far-infrared region; at very long wavelengths it merges into the microwave region. Measurements in the far infrared needed the development of accurately ruled diffraction gratings to replace the prisms as dispersing elements, since salt crystals are opaque in this region. More sensitive detectors than the bolometer were required because of the low energy of the radiation. One such was the Golay detector. An additional issue is the need to exclude atmospheric water vapour because water vapour has an intense pure rotational spectrum in this region. Far-infrared spectrophotometers were cumbersome, slow and expensive.
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.
Cardarine targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not bind the androgen receptor in the way SARMs do.