If you have been reading about GW501516 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 2026-01-25. Where a claim depends on a specific study, the study is described rather than over-claimed.
Safety concerns emerged from long-term animal studies. In rodents given the compound for extended periods, researchers found an increased incidence of certain cancers, including liver and bladder tumors. These findings contributed to the discontinuation of clinical development. Whether similar risks apply to short-term or low-level exposure in humans is not established, and controlled human safety data are limited. The relevance of high-dose rodent carcinogenicity findings to human use remains a subject of debate.
Human trials of GW501516 were small and short in duration. They examined lipid levels, glucose handling, and other metabolic markers, but the programs were halted after the animal cancer findings. No approved therapeutic product exists, and published human data are insufficient for establishing long-term safety. Reports of use for athletic performance come mainly from non-clinical settings and cannot be verified through controlled trials. Independent testing of products sold as cardarine has found inconsistent purity and labeling.
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.
GW501516 acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in transcription of genes related to lipid handling and energy use. Activation of PPARδ can shift skeletal muscle toward greater fatty acid oxidation in animal models, which is one reason it drew interest for metabolic disease and exercise research. The exact downstream effects depend on tissue, species, dose, and duration. Human data are sparse, so many proposed benefits remain hypotheses rather than established clinical outcomes.
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.
| Property | Value | Notes |
|---|---|---|
| Primary target | PPARδ (NR1C2) | Nuclear receptor involved in lipid metabolism |
| Preclinical effect | Increased fatty acid oxidation | Observed in rodent studies |
| Key safety signal | Tumors in rodents after long-term exposure | Contributed to halted clinical development |
| Human trial status | No approved product; development stopped | Limited short-term metabolic data |
| Sport regulatory status | Prohibited at all times | WADA hormone and metabolic modulators class |
Because cardarine is not an approved medicine, no pharmacopeial monograph defines its identity, purity, or storage requirements. Laboratories typically rely on in-house methods and reference standards when testing materials labeled as GW501516. Certificates of analysis may report purity and identity for a specific batch, but their scope varies and they do not guarantee safety or legal status. Independent verification can include high-performance liquid chromatography, mass spectrometry, nuclear magnetic resonance, and elemental analysis. The distinction between research chemical labeling and human use is significant because quality standards and oversight differ.
Cardarine can be detected in biological samples and product materials using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The method separates compounds by chromatography and identifies them by mass-to-charge transitions, allowing low-level detection in urine or blood. Sample preparation often involves enzymatic hydrolysis, solid-phase extraction, or protein precipitation. Certified reference materials and isotope-labeled internal standards improve quantification. Detection windows depend on metabolism, matrix, and assay sensitivity, so no single universal window applies.
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.
Activation of PPARδ changes transcription of genes involved in fatty acid transport, mitochondrial function, and skeletal muscle fuel preference. In rodent studies, pharmacological PPARδ activation was associated with increased endurance and altered body composition. These findings generated interest in performance enhancement, but species differences and study designs limit direct extrapolation to humans. Small human trials were conducted in the 2000s and later discontinued. The extent to which cardarine produces similar metabolic or performance effects in people remains an open question.
== Contaminant == A contaminant is a substance present in nature at a level higher than fixed levels or that would not otherwise be there. This may be due to human activity and bioactivity. The term contaminant is often used interchangeably with pollutant, which is a substance that detrimentally impacts the surrounding environment. While a contaminant is sometimes a substance in the environment as a result of human activity, but without harmful effects, it is sometimes the case that toxic or harmful effects from contamination only become apparent at a later date. The "medium" such as soil or organism such as fish affected by the pollutant or contaminant is called a receptor, whilst a sink is a chemical medium or species that retains and interacts with the pollutant such as carbon sink and its effects by microbes.
It is critical to maintain food safety during processing, packaging, storage, logistics (including cold chain), sale, and use. Conformance to applicable regulations is mandatory. Some are country specific, such as the US Food and Drug Administration and the US Department of Agriculture; others are regional, such as the European Food Safety Authority. Certification programs such as the Global Food Safety Initiative are sometimes used. Food packaging considerations may include: use of hazard analysis and critical control points, verification and validation protocols, Good manufacturing practices, use of an effective quality management system, track and trace systems, and requirements for label content. Special food contact materials are used when the package is in direct contact with the food product. Depending on the packaging operation and the food, packaging machinery often needs specified daily wash-down and cleaning procedures. Health risks of materials and chemicals that are used in food packaging need to be carefully controlled. Carcinogens, toxic chemicals, mutagens etc. need to be eliminated from food contact and potential migration into foods. Besides, the consumers need to be aware of certain chemical products that are packaged exactly like food products to attract them. Most of them have pictures of fruits, and the containers also resemble food packages. However, they can get consumed by kids or careless adults and lead to poisoning. Microplastics and nanoparticles from plastic containers are an increasing concern.
Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the intermediate liquid state. The verb form of sublimation is sublime, or less preferably, sublimate. Sublimate also refers to the product obtained by sublimation. The point at which sublimation occurs rapidly (for definition, see below) is called critical sublimation point, or simply, sublimation point. Notable examples include sublimation of dry ice at room temperature and atmospheric pressure, and that of solid iodine with heating. The reverse process of sublimation is deposition (also called desublimation), in which a substance passes directly from a gas to a solid phase, without passing through the intermediate liquid state. Technically, all solids may sublime, though most sublime at extremely low rates that are hardly detectable under usual conditions. At normal pressures, most chemical compounds and elements possess three different states at different temperatures. In these cases, the transition from the solid to the gas state requires an intermediate liquid state. The pressure referred to is the partial pressure of the substance, not the total (e.g. atmospheric) pressure of the entire system. Thus, any solid can sublime if its vapour pressure is higher than the surrounding partial pressure of the same substance, and in some cases, sublimation occurs at an appreciable rate (e.g. water ice just below 0 °C).
Approximately 152,000 such individuals participated in the plebiscite. However, debate went on whether it was a Polish or German condition at Versailles, since it might have been expected that many Ruhr Area Poles would vote for Poland as well. Therefore, it is also reported that the Polish delegation planned to bring Polish émigrés not only from other parts of Germany, but also from America, to the plebiscite area to strengthen their position, but those plans were not executed. The Polish delegation claimed that was a German condition. According to Richard K. Debo, both the German and the Polish governments believed that the outcome of the plebiscite had been decided by the ongoing Polish-Bolshevik War, which threatened the very existence of the newly-formed Polish state itself and so many Poles in the region voted for Germany for fear that if the area joined Poland, it would soon fall under Soviet rule. During the plebiscite, the Red Army came closer to Warsaw every day and committed crimes against the civilian population. According to several Polish sources, the Germans engaged in a massive persecution of Polish activists and their Masurian supporters and went as far as engaging in regular hunts and murder to influence the vote. The organisation of the plebiscite was also influenced by Britain, which supported Germany out of fear of an increased power for France in postwar Europe. According to Jerzy Minakowski, terror and their unequal status made Poles boycott the preparations for the plebiscite, which allowed the Germans to add ineligible voters.
===== Happiness set point ===== The happiness set point idea is that most people return to an average level of happiness – or a set point – after temporary highs and lows in emotionality. People whose set points lean toward positive emotionality tend to be cheerful most of the time and those whose set points tend to be more negative emotionality tend to gravitate toward pessimism and anxiety. Lykken found that we can influence our level of well-being by creating environments more conductive to feelings of happiness and by working with our genetic makeup. One reason that subjective well-being is for the most part stable is because of the great influence genetics have. Although the events of life have some effect on subjective well-being, the general population returns to their set point.
Sources: en.wikipedia.org
Immune-mediated causes could include transient factors as in Mycoplasma pneumoniae infection (cold agglutinin disease) or permanent factors as in autoimmune diseases like autoimmune hemolytic anemia (itself more common in diseases such as systemic lupus erythematosus, rheumatoid arthritis, Hodgkin's lymphoma, and chronic lymphocytic leukemia). Spur cell hemolytic anemia Any of the causes of hypersplenism (increased activity of the spleen), such as portal hypertension. Acquired hemolytic anemia is also encountered in burns and as a result of certain infections (e.g. malaria). Lead poisoning or poisoning by arsine or stibine causes non-immune hemolytic anemia. Runners can develop hemolytic anemia due to "footstrike hemolysis", the destruction of red blood cells in feet at foot impact. Low-grade hemolytic anemia occurs in 70% of prosthetic heart valve recipients, and severe hemolytic anemia occurs in 3%.
June 15 Iran War: US Vice President JD Vance announces that the Islamabad Memorandum was digitally signed by the US and Iran the previous day. Eight people are killed in a B-52 bomber crash in California. June 16 – SpaceX announces a US$60 billion all-stock deal to acquire Cursor, the developer of the AI coding assistant Cursor, with the transaction expected to close in the third quarter of 2026. June 17 Iran war: The Pentagon reveals that xAI's Grok model was utilized by the US during the war. Trump states that if he does not like the agreement with Iran, the United States will "go right back to dropping bombs". Trump and Iranian President Masoud Pezeshkian sign a memorandum of understanding to end the war. Trump signs the document at the Palace of Versailles, during a dinner with French President Emmanuel Macron following the G7 summit. 2027–2028 United States redistricting: Republicans in the Georgia General Assembly reject an attempt by Governor Brian Kemp to redistrict Georgia’s congressional districts for the 2028 U.S. House of Representatives elections in the state after State House Speaker Jon G. Burns announced that he will not hold a vote to do so.
GOT1/cAST, the cytosolic isoenzyme derives mainly from red blood cells and heart. GOT2/mAST, the mitochondrial isoenzyme is present predominantly in liver. These isoenzymes are thought to have evolved from a common ancestral AST via gene duplication, and they share a sequence homology of approximately 45%. AST has also been found in a number of microorganisms, including E. coli, H. mediterranei, and T. thermophilus. In E. coli, the enzyme is encoded by the aspCgene and has also been shown to exhibit the activity of an aromatic-amino-acid transaminase (EC 2.6.1.57).
PTC Therapeutics, Inc. is a US pharmaceutical company focused on the development of orally administered small molecule drugs and gene therapy which regulate gene expression by targeting post-transcriptional control (PTC) mechanisms in orphan diseases. In September 2009, PTC entered into an agreement with Roche for the development of orally bioavailable small molecules for central nervous system diseases. PTC acquired the Bio-e platform in 2019.
Interpretation for secondary aldosterone deficiency Aldosterone response of several factors from a low base value. This factoring indicates secondary hypoaldosteronism (sodium low, potassium and renin enzyme will be low). Usually doubling to quadrupling from a low base aldosterone value is what is seen in secondary adrenal insufficiency. Decoupling of aldosterone in the ACTH stimulation test is possible (i.e. 2 ng/dl stimming to 20). A result of doubling or more of aldosterone may help in tandem with a cortisol stimulation that doubled or more confirm a diagnosis of secondary adrenal insufficiency. In rare cases, an aldosterone stimulation which did not double, but with the presence of low potassium, low renin and low ACTH indicates atrophy of aldosterone production from the prolonged lack of renin. Similar to the cortisol stimulation in ACTH deficiency, the test interpreter may lack knowledge of how to properly interpret for secondary hypoaldosteronism and think a result of aldosterone doubling or more from a low base value is good.
Sources: en.wikipedia.org
11-Deoxycortisol in mammals has limited biological activity and mainly acts as metabolic intermediate within the glucocorticoid pathway, leading to cortisol. However, in sea lampreys, an early jawless fish species that originated over 500 million years ago, 11-deoxycortisol is the primary and ultimate glucocorticoid hormone with mineralocorticoid properties; 11-deoxycortisol also takes part, by binding to specific corticosteroid receptors, in intestinal osmoregulation in sea lamprey at metamorphosis, during which they develop seawater tolerance before downstream migration. Sea lampreys do not possess the 11β-hydroxylase enzyme (CYP11B1) responsible for converting 11-deoxycortisol to cortisol and 11-deoxycorticosterone to corticosterone, as observed in mammals. The absence of this enzyme in sea lampreys indicates the existence of a complex and highly specific corticosteroid signaling pathway that emerged at least 500 million years ago with the advent of early vertebrates. The lack of cortisol and corticosterone in sea lampreys suggests that the presence of the 11β-hydroxylase enzyme may have been absent during the early stages of vertebrate evolution. The absence of cortisol and corticosterone in sea lampreys suggests that the 11β-hydroxylase enzyme may not have been present early in vertebrate evolution.
Type I: skin, tendon, vasculature, organs, bone (main component of the organic part of bone) Type II: cartilage (main collagenous component of cartilage) Type III: reticulate (main component of reticular fibers), commonly found alongside type I Type IV: forms basal lamina, the epithelium-secreted layer of the basement membrane Type V: found in the skin (especially around hair follicles and sweat glands) and research suggests it is involved in wound healing and bridging the dermis and epidermis. Also found in the placenta.
== Spatial xenon oscillations == Large thermal reactors with low flux coupling between regions may experience spatial power oscillations because of the non-uniform presence of xenon-135. Xenon-induced spatial power oscillations occur as a result of rapid perturbations to power distribution that cause the xenon and iodine distribution to be out of phase with the perturbed power distribution. This results in a shift in xenon and iodine distributions that causes the power distribution to change in an opposite direction from the initial perturbation. The instantaneous production rate of xenon-135 is dependent on the iodine-135 concentration and therefore on the local neutron flux history. On the other hand, the destruction rate of xenon-135 is dependent on the instantaneous local neutron flux. The combination of delayed generation and high neutron-capture cross section produces a diversity of impacts on nuclear reactor operation. The mechanism is described in the following four steps.
A US- and UK-backed coup d'état in 1953 deposed the democratically-elected Iranian prime minister Mohammad Mosaddegh due to his nationalization of the oil industry, strengthening the rule of Shah Mohammad Reza Pahlavi. Israel maintained ties with Iran as part of its alliance of the periphery strategy. Resentment of the Shah's autocratic rule led to the 1979 revolution in which Pahlavi was overthrown and replaced by an Islamic republic. Iran severed diplomatic ties with the US and Israel and held the American embassy staff hostage, releasing them after signing the Algiers Accords (1981), in which, among other things, the US agreed not to intervene in Iranian affairs anymore. During the Iran–Iraq War, the US supported Iraq. In 1988, a US warship struck an Iranian mine, and the US responded by attacking Iran's navy. A few months later, the US mistakenly shot down a civilian Iranian flight. Iran started a ballistic missile program to deter Iraqi missile attacks on Iranian cities during the 1980–88 Iran–Iraq War and to compensate for its lack of a modern air force due to sanctions. Starting in 1985, Iran began engaging in proxy conflicts throughout the Middle East. These proxy groups became part of the informal 'Axis of Resistance' committed primarily to countering American, Israeli, Saudi, Emirati, and sometimes Turkish influence in the region. In 2002, Iran's covert nuclear program was first revealed, and Iran denied seeking a weapon. In 2003, Iran's AMAD Project was suspended following Supreme Leader Ali Khamenei's fatwa against nuclear weapons.
Ice-nine is a fictional material that appears in Kurt Vonnegut's 1963 novel Cat's Cradle. Ice-nine is described as a polymorph of ice which instead of melting at 0°C (32°F) melts at 45.8°C (114.4°F). When ice-nine comes into contact with liquid water below 45.8°C, it acts as a seed crystal and causes the solidification of the entire body of water, which quickly crystallizes as more ice-nine. As humans are 55-60% water, ice-nine kills nearly instantly when ingested or brought into contact with soft tissues exposed to the bloodstream, such as the eyes or lips. In the story, ice-nine is invented by Dr. Felix Hoenikker while working on the Manhattan Project in response to a suggestion from a Marine general, who complained about soldiers having to deal with mud on the battlefield. The project is abandoned when it becomes clear that any quantity of the substance would have the power to destroy all life on Earth. In the novel's climax, the Earth's oceans are accidentally frozen solid by ice-nine, prompting a doomsday scenario. Vonnegut encountered the idea of ice-nine while working at General Electric. He attributes the idea of ice-nine to his brother Bernard Vonnegut, who was researching the formation of ice crystals in the atmosphere. A later account of the events attributes the idea to the chemist Irving Langmuir, who devised the concept while helping H.G. Wells conceive ideas for stories. Vonnegut decided to adapt the idea into a story after Langmuir's death in 1957.
Sources: en.wikipedia.org
Rodent studies reported increased endurance and fat oxidation after GW501516 exposure. Long-term studies also found higher rates of some tumors, which led to halted development.
Small short-term human trials examined metabolic markers such as lipids and glucose. The trials did not continue after rodent cancer findings, so long-term human safety is unknown.
Controlled human trials have not established a performance benefit. Anecdotal reports exist, but they are not reliable evidence.
It binds and activates PPARδ, a nuclear receptor that influences gene expression related to fatty acid metabolism and energy balance. This mechanism has been studied mainly in animals and cell models, not established as a safe human therapy.