If you have been reading about carcinogenicity 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.
Updated 2025-08-09. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
GW501516 acts on PPARδ, a nuclear receptor that helps regulate fatty acid oxidation and energy homeostasis. In animal studies, activation of this receptor was associated with increased endurance and changes in lipid metabolism. Human trials examined effects on blood lipids and other metabolic markers, but the compound did not advance to approval. Rodent studies later reported tumors in multiple tissues at doses used in those experiments. Whether those findings translate to human risk remains uncertain, and the clinical relevance of the animal data is still debated.
| 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 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.
A common misconception is that cardarine has been proven safe for human use. In reality, human clinical data are limited, and long-term animal studies have raised concerns about cancer. Another misconception is that it is a supplement or vitamin-like compound. It is a synthetic research chemical with no approved medical indication. Scientific discussion often focuses on its mechanism and detection rather than therapeutic use. Regulatory and anti-doping literature treats it primarily as a prohibited substance.
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.
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.
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.
Laboratory studies indicate that GW501516 activates PPARδ, a nuclear receptor involved in fatty acid oxidation and energy metabolism. In rodent experiments, treated animals often showed increased endurance and reduced fat mass. These effects were observed under controlled conditions and do not establish safe or effective use in humans. The exact dose-response relationship in humans remains poorly characterized. Species differences in metabolism can affect how results translate across animals and people.
Historian Eduardo Torres Cuevas has written:"A question arises during this period: Was it possible that individuals within the island's power structure were linked to Freemasonry? Much remains to be studied in this regard. The fact that, during those years, the Cuban political government, as well as a significant portion of the emerging Havana oligarchy, were closely linked to the Count of Aranda's group in Spain, gave rise to the hypothesis that some of its members were Freemasons and, therefore, held meetings in Cuba... This hypothesis appears to have faded after the work of Dr. José Antonio Ferrer Benimeli, who clarifies the historical enigma of the Count of Aranda as a Freemason."In 1767, in mainland Spain, the Grand Logia Española changed its name to Gran Oriente and was recognized by the Grand Lodge of England.
=== Back to the Capital - Illinois General Assembly === SHIELD Illinois started testing visitors, staff, and members of the Illinois General Assembly in January 2021 which coincided with the legislators' return to in-person attendance in Springfield for the legislative session. Testing was mandatory for non-vaccinated visitors and capitol staff. Testing was optional for members.
Sydney Harbour A unit of volume used in Australia for water. One Sydney Harbour is the amount of water in Sydney Harbour: approximately 562 gigalitres (562,000,000 cubic metres, or 0.562 cubic kilometres); or in terms of the more unusual measures above, about 357 Melbourne Cricket Grounds, 238,000 Olympic Swimming pools, or 476,000 acre-feet. The Grand Canyon With a volume measure approximately 4 orders of magnitude greater than Sydney Harbour, the volume of the Grand Canyon may be used to visualize even larger things, like the magma chamber underneath Yellowstone and other things. According to the National Park Service, the volume of the Grand Canyon is 4.17 trillion cubic metres (5.45 trillion cubic yards) which is 4,170 km3 (1,000 mi3).
Sources: en.wikipedia.org
== Criticism == Numerous critiques have been made regarding the use of impact factors, both in terms of their statistical validity and also of their implications for how science is carried out and assessed. A 2007 study noted that the most fundamental flaw is that impact factors present the mean of data that are not normally distributed, and suggested that it would be more appropriate to present the median of these data. There is also a more general debate on the validity of the impact factor as a measure of journal importance and the effect of policies that editors may adopt to boost their impact factor (perhaps to the detriment of readers and writers). Other criticism focuses on the effect of the impact factor on the behavior of scholars, editors and other stakeholders. Criticism of impact factors also extends to its impact on researcher behavior. While the emphasis on high-impact journals may lead to strategic publishing practices that prioritize journal prestige over the quality and relevance of research, it's important to acknowledge the "privilege paradox". Younger researchers, particularly those from under-represented regions, often lack the established reputation or networks to secure recognition outside of these metrics. This can lead to a narrow focus on publishing in top-tier journals, potentially compromising the diversity of research topics and methodologies. Further criticisms argue that emphasis on impact factor results from the negative influence of neoliberal politics on academia.
=== Transdermal administration === Transdermal estradiol is available in the forms of patches, gels, emulsions, and sprays. In the case of gels, emulsions, and sprays, the route is sometimes referred to as topical rather than as transdermal. Topical administration can also refer to vaginal administration of gels and creams however. Estradiol has moderate skin permeability, which is based on the lipophilicity and hydrophilicity of a compound. In general, the more polar groups, such as hydroxyl groups, that are present in a steroid, and hence the more hydrophilic and less lipophilic it is, the lower its skin permeability. For this reason, estrone and progesterone have higher skin permeability, while estriol and cortisol have lower skin permeability. The transdermal bioavailability of estradiol in an alcohol solution is approximately 10%. Transdermal estradiol reservoir patches have been reported to have a bioavailability of 3 to 5%. Estradiol is a highly potent compound and circulates at picomolar concentrations (pg/mL), which makes it ideal for transdermal application as only small amounts of substance need to be delivered across the skin. Conversely, progesterone, which circulates at levels in the nanomolar range and requires a far higher quantity of substance for biological effect, is not well-suited for transdermal delivery.
== Methods == Quantitative chemical analysis is a key part of environmental chemistry, since it provides the data that frame most environmental studies. Common analytical techniques used for quantitative determinations in environmental chemistry include classical wet chemistry, such as gravimetric, titrimetric and electrochemical methods. More sophisticated approaches are used in the determination of trace metals and organic compounds. Metals are commonly measured by atomic spectroscopy and mass spectrometry: Atomic Absorption Spectrophotometry (AAS) and Inductively Coupled Plasma Atomic Emission (ICP-AES) or Inductively Coupled Plasma Mass Spectrometric (ICP-MS) techniques. Organic compounds, including PAHs, are commonly measured also using mass spectrometric methods, such as Gas chromatography-mass spectrometry (GC/MS) and Liquid chromatography-mass spectrometry (LC/MS). Tandem Mass spectrometry MS/MS and High Resolution/Accurate Mass spectrometry HR/AM offer sub part per trillion detection. Non-MS methods using GCs and LCs having universal or specific detectors are still staples in the arsenal of available analytical tools. Radioactive materials are assayed by particle counters and scintillation counter. Bioassays and immunoassays are utilized for toxicity evaluations of chemical effects on various organisms. Polymerase Chain Reaction PCR is able to identify species of bacteria and other organisms through specific DNA and RNA gene isolation and amplification and is showing promise as a valuable technique for identifying environmental microbial contamination.
=== 21st century === In 2001, UPS acquired Mail Boxes Etc., Inc., a franchised network of packing and shipping retail centers across the United States and Canada. In 2003, the company rebranded the Mail Boxes, Etc. network as The UPS Store. In 2004, UPS entered the heavy freight business with the purchase of Menlo Worldwide Forwarding, a former subsidiary of Menlo Worldwide; UPS rebranded it as UPS Supply Chain Solutions. The purchase price was US$150 million and the assumption of US$110 million in long-term debt. On August 5, 2005, UPS announced that it had completed its acquisition of less-than-truckload (LTL) trucking company Overnite Transportation for US$1.25 billion. This was approved by the FTC and Overnite shareholders on August 4, 2005. On April 28, 2006, Overnite officially became UPS Freight. In 2005, UPS offered non-stop delivery service between Guangzhou and the United States. On October 3, 2005, UPS completed the purchase of Lynx Express, one of the largest independent parcel carriers in the United Kingdom, for £55.5 million (US$97.1 million) after receiving approval for the transaction from the European Commission. The first joint package car center operation in Dartford, Kent, was opened in 2006. On August 28, 2007, United Parcel Service celebrated its 100th anniversary. All Nippon Airways, a Star Alliance member, and UPS formed a cargo alliance and codeshare agreement to transport member cargo in 2008, similarly to an airline alliance.
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. Cardarine is a PPARδ agonist, while selective androgen receptor modulators act on androgen receptors. The two classes differ in receptor target and downstream effects.