PPARδ comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| 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 |
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.
A persistent misconception is that cardarine is a fat-burning drug or a safe alternative to anabolic steroids. No approved therapeutic product exists, and human safety data are limited. The tumor findings in rodents remain a central concern in scientific reviews. Products sold online may contain inaccurate labels, impurities, or different compounds entirely, which complicates any assessment of effects. Independent testing of such products has reported frequent mislabeling. For these reasons, discussions in the literature emphasize risks and unknowns rather than benefits.
Cardarine is not approved for human therapeutic use in any major jurisdiction. It appears on the World Anti-Doping Agency Prohibited List as a PPARδ agonist within the hormone and metabolic modulators category. Sports organizations test for it because it has been detected in athlete samples and seized products. Regulatory actions against marketed research chemical versions have occurred in several countries, though enforcement varies. Availability through unregulated channels complicates oversight.
Analytical laboratories typically identify cardarine and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is a common matrix in anti-doping testing, while blood and tissue may be used in research settings. Detection windows depend on the assay, the sample matrix, and the compound's metabolism. Because cardarine is extensively metabolized, laboratories often target specific metabolites to improve sensitivity and confirmation. Reference standards are required for reliable quantification. Method validation includes checks for selectivity, linearity, and carryover.
Quality assessment for cardarine samples usually combines identity, purity, and impurity testing. Nuclear magnetic resonance spectroscopy and mass spectrometry can confirm molecular structure, while high-performance liquid chromatography estimates purity. Certificates of analysis from testing laboratories may list these results, but they do not establish safety or legality. In the absence of approved manufacturing, products sold online may contain the wrong compound, variable amounts, or unlisted contaminants. Independent verification is therefore central to analytical work and to interpreting any reported biological activity.
Laboratory detection of GW501516 commonly uses liquid chromatography coupled with tandem mass spectrometry. The method can identify the parent compound or its metabolites in urine and blood after sample cleanup. Protein precipitation, solid-phase extraction, or enzymatic hydrolysis may precede analysis, depending on the matrix. Reference standards are required for accurate quantification and confirmation. Because the compound is not approved, testing often occurs in anti-doping, forensic, or research settings rather than routine clinical care. Results are reported with limits of detection and quantification.
Stability of GW501516 depends on form, temperature, light exposure, and moisture. Solid reference material is typically stored frozen or refrigerated in a desiccator and protected from light. Solutions in organic solvents such as dimethyl sulfoxide are often kept frozen in aliquots to reduce freeze-thaw cycling. Aqueous solubility is low, so aqueous stock solutions can be difficult to prepare without cosolvents. Degradation may appear as changes in chromatographic purity or mass spectral signal. Stability studies are needed to establish shelf life for any specific preparation.
Croton lechleri is a species of flowering plant in the spurge family, Euphorbiaceae, that is native to northwestern South America. It is commonly known as sangre de grado (sic, Peruvian Spanish), sangre de drago (Ecuadorian Spanish) or sangre de grada (sic, Bolivian Spanish). They refer to this tree's (and several related species') thick red latex. The latex has medicinal properties, and is used by local peoples as a liquid bandage, applied to seal wounds, as it dries quickly to form a protective skin-like barrier. Its use by native people has led to scientific study and observation of its in vitro antioxidant activity as well as both mutagenic and antimutagenic behavior. The latex also contains a number of chemicals, including taspine. Oligomeric proanthocyanidins, another kind of chemical contained in the latex, have been investigated for the treatment of HIV-associated diarrhea under the name crofelemer. In January 2013, crofelemer, under the trade name Mytesi, was approved by the FDA for the treatment of non-infectious diarrhea in HIV+ patients.
The General Principles of Software Validation (FDA 2002) defines verification as "Software verification provides objective evidence that the design outputs of a particular phase of the software development life cycle meet all of the specified requirements for that phase." It also defines Validation as "Confirmation by examination and provision of objective evidence that software specifications conform to user needs and intended uses, and that the particular requirements implemented through software can be consistently fulfilled". The software validation guideline states: “The software development process should be sufficiently well planned, controlled, and documented to detect and correct unexpected results from software changes." Annex 11 states "The validation documentation and reports should cover the relevant steps of the life cycle." Weichel (2004) recently found that over twenty warning letters issued by the FDA to pharmaceutical companies specifically cited problems in Computer System Validation between 1997 and 2001. Probably the best known industry guidance available is the GAMP Guide, now in its fifth edition and known as GAMP5 published by ISPE (2008). This guidance gives practical advice on how to satisfy regulatory requirements.
=== Food storage === Xerophiles are a concern to food storage industry due to their ability to bypass common food preservation methods. Many foods are preserved by creating high osmotic pressures that dry out and kill any microbes that attempt to culture in the food. Foods such as honey or jam have such high levels of sugar and low levels of water normal micro organisms can not grow on them. However, xerophilic organisms can grow in these mediums posing a threat to food safety. The common food preservation methods of reducing water activity (food drying) may not always be sufficient to prevent the growth of xerophilic organisms, often resulting in food spoilage. Some mold and yeast species are xerophilic. Mold growth on bread is an example of food spoilage by xerophilic organisms. Complete dehydration based on the freeze-drying technique with effective protection inside a tight packaging system, strictly impervious to water and atmospheric gases (O2 and CO2), may be required for long-term preservation of food and pharmacochemical substances (antibiotics, vaccines...). Freeze drying can limit the microbial activity on the long term, as long as the product remains perfectly dry in a hermetically sealed and intact package, but it is not a sterilisation technique per se, because after rehydration, even if many dehydrated cells suffer irreversible and lethal damages, some resistant spores and bacterial endospores can still be revived again, and multiplied, by means of microbiological cultures if the product was not initially sterilized by applying a proven technique.
=== EC 2.8.4: Transferring alkylthio groups === EC 2.8.4.1: coenzyme-B sulfoethylthiotransferase EC 2.8.4.2: arsenate-mycothiol transferase EC 2.8.4.3: tRNA-2-methylthio-N6-dimethylallyladenosine synthase EC 2.8.4.4: [ribosomal protein S12] (aspartate89-C3)-methylthiotransferase EC 2.8.4.5: tRNA (N6-L-threonylcarbamoyladenosine37-C2)-methylthiotransferase
=== Homonuclear nuclear magnetic resonance === With unlabelled protein the usual procedure is to record a set of two-dimensional homonuclear nuclear magnetic resonance experiments through correlation spectroscopy (COSY), of which several types include conventional correlation spectroscopy, total correlation spectroscopy (TOCSY) and nuclear Overhauser effect spectroscopy (NOESY). A two-dimensional nuclear magnetic resonance experiment produces a two-dimensional spectrum. The units of both axes are chemical shifts. The COSY and TOCSY transfer magnetization through the chemical bonds between adjacent protons. The conventional correlation spectroscopy experiment is only able to transfer magnetization between protons on adjacent atoms, whereas in the total correlation spectroscopy experiment the protons are able to relay the magnetization, so it is transferred among all the protons that are connected by adjacent atoms. Thus in a conventional correlation spectroscopy, an alpha proton transfers magnetization to the beta protons, the beta protons transfers to the alpha and gamma protons, if any are present, then the gamma proton transfers to the beta and the delta protons, and the process continues. In total correlation spectroscopy, the alpha and all the other protons are able to transfer magnetization to the beta, gamma, delta, epsilon if they are connected by a continuous chain of protons. The continuous chain of protons are the sidechain of the individual amino acids.
Sources: en.wikipedia.org
In light of these events, Rush's record label tried to pressure the members into moulding their next album in a more commercially friendly and accessible fashion; the band ignored the requests and developed their next album 2112 (1976) with a 20-minute title track divided into seven sections. Despite that, the album was the Rush's first taste of significant commercial success as it reached No. 5 in Canada, becoming their first to reach double platinum certification. Rush toured in support of 2112 between February 1976 and June 1977 with concerts in Canada, the US, and for the first time Europe, with dates in the UK, Sweden, Germany, and the Netherlands. The three sold-out shows at Massey Hall in Toronto in June 1976 were recorded for Rush's debut live album, All the World's a Stage. Released in September of that year, the double album reached No. 6 in Canada and became Rush's first to crack the US top 40. Record World wrote: "Building its American reputation slowly but steadily Rush stands poised for breaking through all the way via this two record live set [...] All the highly charged electricity is here in an explosive setting." The liner notes include the statement, "This album to us, signifies the end of the beginning, a milestone to mark the close of chapter one, in the annals of Rush."
=== Part I: Democratic Rights === Explicitly drawing from the United Nations' Universal Declaration of Human Rights, Article One of the Charter declares that every individual is entitled to the following:"a. The freedom of conscience, expression, association, and peaceable assembly; b. The right to engage in unrestricted political activity and to organize political parties, provided the exercise of such right does not infringe upon the rights of others."Article Two concerns the rights of "nations, nationalities, and peoples" in Ethiopia, referring to the various ethnolinguistic groups in the country. Not only does the Charter protect nationalities' right to exercise their autonomy, but it also allows them to secede ("self-determination of independence") if they so wish.
=== Examples === In Belews Lake North Carolina, 19 species of fish were eliminated from the lake due to 150–200 μg Se/L wastewater discharged from 1974 to 1986 from a Duke Energy coal-fired power plant. At the Kesterson National Wildlife Refuge in California, thousands of fish and waterbirds were poisoned by selenium in agricultural irrigation drainage.
=== Ubiquitination of non-protein substrates === Although ubiquitination was historically considered a protein-specific post-translational modification, recent studies have shown that ubiquitin can also be conjugated to certain non-protein molecules. These include lipopolysaccharides (LPS), phospholipids and other metabolites. A notable example is the E3 ligase RNF213 which can attach ubiquitin to the lipid A moiety of bacterial LPS, promoting xenophagic clearance of invading bacteria. These findings expand the known scope of ubiquitin signaling beyond classical post-translational protein modification.
American black bears have also been recorded similarly preying on elk calves in Idaho and moose calves in Alaska. Predation on adult deer is rare, but it has been recorded. They may even hunt prey up to the size of adult female moose, which are considerably larger than themselves, by ambushing them. There is at least one record of a male American black bear killing two bull elk over the course of six days by chasing them into deep snow banks, which impeded their movements. In Labrador, American black bears are exceptionally carnivorous, living largely off caribou, usually young, injured, old, sickly or dead specimens, and rodents such as voles. This is believed to be due to a paucity of edible plant life in this sub-Arctic region and a local lack of competing large carnivores (including other bear species). Like brown bears, American black bears try to use surprise to ambush their prey and target the weak, injured, sickly or dying animals in the herds. Once a deer fawn is captured, it is frequently torn apart alive while feeding. If it is able to capture a mother deer in spring, the bear frequently begins feeding on the udder of lactating females, but generally prefers meat from the viscera. Bears often drag their prey to cover, preferring to feed in seclusion. The skin of large prey is stripped back and turned inside out, with the skeleton usually left largely intact. Unlike gray wolves and coyotes, bears rarely scatter the remains of their kills. Vegetation around the carcass is usually matted down, and their droppings are frequently found nearby.
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.
Anti-doping laboratories typically use LC-MS/MS to detect GW501516 and its metabolites in urine. The method is sensitive and can identify the compound at low concentrations. Detection depends on sample timing, metabolism, and the specific assay.