Investigational drug 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 2025-07-23. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
GW501516 acts as an agonist at the peroxisome proliferator-activated receptor delta, a nuclear receptor that regulates gene expression. Activation shifts transcription toward genes involved in fatty acid uptake, oxidation, and energy expenditure. The compound does not bind the androgen receptor and therefore differs from anabolic steroids and SARMs. In rodent models, this metabolic shift has been linked to increased running endurance and reduced fat accumulation. The exact downstream pathways in humans remain incompletely characterized.
| Property | Value | Notes |
|---|---|---|
| Common name | Cardarine | Common internet and media name. |
| Research code | GW501516 | Also written GW-1516. |
| Drug class | PPARδ agonist | Not a selective androgen receptor modulator. |
| Development status | Discontinued | Clinical development halted after rodent cancer findings. |
| Regulatory status | Prohibited in sport | Listed by WADA; not approved as medicine. |
Laboratory handling focuses on identity, purity, and stability. Reference standards are typically stored cold and dry, protected from light, because solutions can degrade over time. Analytical checks may use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Impurities and related substances can be separated chromatographically and compared with a known standard. Because cardarine is not an approved drug, compendial monographs are absent, and laboratories often rely on in-house methods. Reported purity varies among unregulated products and should not be assumed from a label.
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.
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.
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.
Developed over the course of five years, Entropy: Zero 2 was released in August 2022 to positive reviews on Steam, and went on to win Mod DB's 2022 "Mod of the Year" award in the "Players Choice" category. Flipside - A side-scrolling platform game that allows the player to "flip" the game world around to its backside, altering the means a player can traverse a level. Half-Life 2: Overcharged - A single-player mod for Half-Life 2 that adds new enemies and locations as well as cut content, extending the base game. Originally released in 2022, the mod gained notoriety in 2024 due to the mod developers blacklisting content creators that criticized the mod by targeting their Steam IDs and crashing their game. This led to the mod being review bombed on Mod DB. Jurassic Life - A modification based on the first Jurassic Park film. The game acts as a side story to the movie where the player takes the role of the park's game warden, Robert Muldoon. Korsakovia - A single-player mod for Half-Life 2. It was developed by The Chinese Room and released September 19, 2009. In Korsakovia, the player travels through the delusions of Christopher, a man suffering from Korsakoff's Syndrome. The player hears the voices of Christopher and a doctor as they try to work out what is wrong with Christopher. Minerva - An episodic single-player mod based in the Half-Life 2 universe, using storytelling inspired by classic games such as Marathon and System Shock. Operation Black Mesa - An upcoming remake of the Half-Life expansion Opposing Force developed by Tripmine Studio.
=== Roles in endocrine regulation === Decreases basal corticotropin level and blocks its release. Stimulates release of luteinizing hormone (LH). Stimulates release of somatoliberin and somatotrophin secretion and inhibits somatostatin secretion.
In May 1937, they issued parallel reports, one in the Zeitschrift für Physik with Meitner as the principal author, and one in the Chemische Berichte with Hahn as the principal author. Hahn concluded his by stating emphatically: Vor allem steht ihre chemische Verschiedenheit von allen bisher bekannten Elementen außerhalb jeder Diskussion ("Above all, their chemical distinction from all previously known elements needs no further discussion"). Meitner, however, was increasingly uncertain. She considered the possibility that the reactions were from different isotopes of uranium; three were known: uranium-238, uranium-235 and uranium-234. However, when she calculated the neutron cross section, it was too large to be anything other than the most abundant isotope, uranium-238. She concluded that it must be another case of the nuclear isomerism that Hahn had discovered in protactinium. She therefore ended her report on a very different note to Hahn, reporting that: Also müssen die Prozesse Einfangprozesse des Uran 238 sein, was zu drei isomeren Kernen Uran 239 führt. Dieses Ergebnis ist mit den bisherigen Kernvorstellungen sehr schwer in Übereinstimmung zu bringen ("The processes must be neutron capture by uranium-238, which leads to three isomeric nuclei of uranium-239. This result is very difficult to reconcile with current concepts of the nucleus.") With the Anschluss, Germany's annexation of Austria on 12 March 1938, Meitner lost her Austrian citizenship, and fled to Sweden.
== Classification == As a definition of "cell type" is yet to be agreed, it is not possible yet to arrive at a precise number of human cell types. There is, for example, significant variation in these cell types depending on the specific surface proteins they possess. An extensive listing of human cell types was published by Vickaryous and Hall in 2006, collecting 411 different types of human cells, including 145 types of neurons. The Human Cell Atlas project, which started in 2016, had as one of its goals to "catalog all cell types (for example, immune cells or brain cells) and sub-types in the human body". By 2018, the Human Cell Atlas description based the project on the assumption that "our characterization of the hundreds of types and subtypes of cells in the human body is limited", but the word hundreds was removed in later versions. On 2021, Stephen Quake guessed that the upper limit of the number of human cell types would be around 6000, based on a reasoning that "if biologists had discovered only 5% of cell types in the human body, then the upper limit of cell types to discover is somewhere around 6000 (i.e., 300/0.05)." Other different efforts have used different numbers. A count of cells in the human body published in 2023 divided the cells in about 400 types to perform the calculation.
Sources: en.wikipedia.org
The compound was first administered to two normal human volunteers by Abass Alavi in August 1976 at the University of Pennsylvania. Brain images obtained with an ordinary (non-PET) nuclear scanner demonstrated the concentration of FDG in that organ. Later, the substance was used in dedicated positron tomographic scanners, to yield the modern procedure. The logical extension of positron instrumentation was a design using two two-dimensional arrays. PC-I was the first instrument using this concept and was designed in 1968, completed in 1969 and reported in 1972. The first applications of PC-I in tomographic mode as distinguished from the computed tomographic mode were reported in 1970. It soon became clear to many of those involved in PET development that a circular or cylindrical array of detectors was the logical next step in PET instrumentation. Although many investigators took this approach, James Robertson and Zang-Hee Cho were the first to propose a ring system that has become the prototype of the current shape of PET. The first multislice cylindrical array PET scanner was completed in 1974 at the Mallinckrodt Institute of Radiology by the group led by Ter-Pogossian. The PET–CT scanner, attributed to David Townsend and Ronald Nutt, was named by Time as the medical invention of the year in 2000.
f. antarctica (Vain.) Hue (1915) is now Polycauliona antarctica f. ectaneoides (Nyl.) Boistel (1903) is now Xanthoria ectaneoides f. ectaniza Boistel (1903) is now Rusavskia ectaniza f. polycarpa (Hoffm.) Arnold (1881) is now Polycauliona polycarpa subsp. calcicola (Oxner) Clauzade & Cl.Roux (1985) is now Xanthoria calcicola subsp. phlogina (Ach.) Sandst. (1912) is now Scythioria phlogina var. aureola (Ach.) Th.Fr. (1860) is now Xanthoria aureola var. australis Zahlbr. (1917) is now Jackelixia australis var. contortuplicata (Ach.) H.Olivier (1894) is now Xanthaptychia contortuplicata var. incavata (Stirt.) Js. Murray (1960) is now Dufourea incavata var. lobulata (Flörke) Rabenh. (1870) is now Seawardiella lobulata var. mandschurica Zahlbr. (1931) is now Zeroviella mandschurica var. rutilans (Ach.) Maheu & A.Gillet (1924) is now Xanthoria rutilans
Tissue engineering aims to replace lost or damaged tissues within the body. The success of such efforts has depended greatly upon the ability to direct cell behavior and encourage regeneration of tissues. A key method of doing so utilizes ECM-derived ligands such as RGD to control cellular responses to a biomaterial, such as attachment, proliferation, and differentiation.
A notable and unusual building in the area is the so-called "Fetta di Polenta" (lit. 'polenta slice'), formerly known as Casa Scaccabarozzi. This building is where Corso San Maurizio meets Via Giulia di Barolo, and it is one of the most peculiar examples of Turin architecture: a thin trapezoid 27 m (89 ft) wide on Via Giulia Di Barolo, 5 m (16 ft) on Corso San Maurizio and just 0.70 m (2 ft 4 in) wide on the opposite end. It was designed in 1840 by Alessandro Antonelli for his wife, Francesca Scaccabarozzi. The curious name comes from the shape of the palace, which resembles a "slice of polenta", and also because it is painted with an ochre colour. In the surroundings, in Via Vanchiglia 8 (although in downtown and not really in Vanchiglia anymore), there is another trapezoid house, albeit with less extreme design: similarly, this building is nicknamed "Fetta di Formaggio" (lit. 'cheese slice'), built in 1832 for the rich Marchese Birago di Vische by the architect Antonio Talentino. Other notable buildings are the town public baths, eclectic building built in 1905 (Corso Regina Margherita crossing Via Vanchiglia), and theTeatro della Caduta theatre, opened in 2003 in Via Michele Buniva 23, which with its 45 seats is the smallest theatre in Turin and among the smallest theatres in Europe. In Corso Regina Margherita, another notable building is the former Opera pia Reynero, a charitable organisation. The building was built in 1892.
==== Leucine ==== The ammonia fixed as part of the glutamate dehydrogenase enzyme reaction in the neurons is transaminated into α-ketoisocaproate to form the branched-chain amino acid leucine, which is exported to the astrocytes, where the process is reversed. α-ketoisocaproate is transported in the other direction.
Sources: en.wikipedia.org
No. Cardarine is a PPARδ agonist, while selective androgen receptor modulators act on androgen receptors. The two classes differ in receptor target and downstream effects.
Preclinical rodent studies reported cancers, including liver and bladder tumors, at tested doses. The human relevance of those findings is uncertain, but development was discontinued. No approved human product resulted.
No. It remains an investigational compound without approved therapeutic labeling. Sports regulators prohibit its use, and health agencies have warned against consuming it.
It targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not act primarily on androgen receptors. This distinction separates it from SARMs.