This is a working overview of PPAR delta, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-09-13. 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.
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.
| 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.
Fermentation is less efficient at using the energy from glucose: only 2 ATP are produced per glucose, compared to the 38 ATP per glucose nominally produced by aerobic respiration. Glycolytic ATP, however, is produced more quickly. For prokaryotes to continue a rapid growth rate when they are shifted from an aerobic environment to an anaerobic environment, they must increase the rate of the glycolytic reactions. For multicellular organisms, during short bursts of strenuous activity, muscle cells use fermentation to supplement the ATP production from the slower aerobic respiration, so fermentation may be used by a cell even before the oxygen levels are depleted, as is the case in sports that do not require athletes to pace themselves, such as sprinting.
It was often intercepted by the P-51 "fighter sweeps" before it could attack the bombers. However, German attacks against bombers could be effective when they did occur; the bomber-destroyer Fw 190As swept in from astern and often pressed their attacks to within 90 m (100 yd).
Tillman Gerngross (born November 15, 1963) is an Austro-American scientist. He is a professor of bioengineering at the Thayer School of Engineering at Dartmouth College, and an adjunct professor in the departments of biology and chemistry at Dartmouth. Gerngross has been an active inventor and to date his work has resulted in the founding of multiple companies (GlycoFi, Inc., Adimab LLC, Arsanis, Inc., Alector [Nasdaq:ALEC], Avitide, Inc., Amagma, Inc., Ankyra, and Adagio [Nasdaq:ADGI]) and over a dozen U.S. and international patents. Gerngross was elected a member of the National Academy of Engineering in 2017.
Sources: en.wikipedia.org
== Further reading == Whitten, Kenneth W.; Davis, Raymond E; Peck, M. Larry (2002). General chemistry. Fort Worth: Thomson Learning. ISBN 978-0-03-021017-4. Whitten, Kenneth W; Gailey, Kenneth D (1981). General chemistry. Philadelphia: Saunders College Pub. ISBN 978-0-03-057866-3. Petrucci, Ralph H.; Herring, F. Geoffrey; Madura, Jeffry; Bissonnette, Carey; Pearson (2017). General chemistry: principles and modern applications. Toronto: Pearson. ISBN 978-0-13-293128-1. Vogel, Arthur Israel; Furniss, B. S; Tatchell, Austin Robert (1978). Vogel's Textbook of practical organic chemistry. New York: Longman. ISBN 978-0-582-44250-4.
=== Regier et al. (2010) === A 2010 study of nuclear genomes (Regier et al.) strongly supports Pancrustacea and strongly favour Mandibulata (Myriapoda + Pancrustacea) over Paradoxopoda (Myriapoda + Chelicerata). According to this study, Pancrustacea is divided into four lineages: Oligostraca (Ostracoda, Mystacocarida, Branchiura, Pentastomida), Vericrustacea (Malacostraca, Thecostraca, Copepoda, Branchiopoda), Xenocarida (Cephalocarida, Remipedia) and Hexapoda, with Xenocarida as a sister group to the Hexapoda (comprising "Miracrustacea"). New clades proposed by Regier et al. are:
2.4×1034 years for decay to a positron and a neutral pion (p → e+ + π0), 1.6×1034 years for decay to an antimuon and a neutral pion (p → μ+K0), 0.59×1034 years for decay to an muon antineutrino and a positive kaon (p → ν̄K+). Two Nobel prizes for neutrino physics were awarded to scientists based on work using experimental facilities originally designed to detect proton decay. In 2002, Masatoshi Koshiba was awarded "for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos", by upgrading the KamiokaNDE experiment. (sharing half prize with Raymond Davis Jr. for the same motivations).T. Kajita of the Super-Kamiokane collaboration was awarded the 2015 Nobel Prize "for the discovery of neutrino oscillations, which shows that neutrinos have mass", jointly to Art McDonald of the SNO experiment.
== Discovery and structure == In 1991 a research group led by Clarence A. Ryan, isolated an 18 amino acid polypeptide from tomato leaves that induced the production of protease inhibitor proteins (PIs) in response to wounding. Experiments using synthetic radio-labelled forms of the polypeptide demonstrated that it was able to travel systemically through the plant and induce PI production in unwounded leaves. Because of the systemic nature of the wounding signal, it was named systemin, it was the first polypeptide found to function as a hormone in plants. mRNA encoding for systemin is found in all tissues of the plant except the roots. Later studies identified homologs of tomato systemin in other members of the Solanaceae including potato, black nightshade and bell pepper. Systemins have only been identified in the Solaneae subtribe of the Solanaceae, but other members of the family, such as tobacco, also respond to wounding by systemically producing protease inhibitors.
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.