If you have been reading about PPARδ 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 2025-09-27. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Published human data are sparse and mostly come from early-phase trials. Those studies examined short-term changes in lipids, glucose, and exercise capacity, but they were not large enough to establish efficacy or long-term safety. Some animal experiments reported increased running endurance, yet such findings do not prove a performance benefit in people. Anti-doping laboratories detect GW501516 and its metabolites in urine or blood using liquid chromatography-tandem mass spectrometry. Detection windows depend on dose, sample type, and individual metabolism. The method is sensitive enough to identify trace residues in tested samples.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white solid | Typical form of reference material |
| Solubility | Low in water; soluble in DMSO | Used to prepare stock solutions |
| Typical storage | -20 °C, desiccated, protected from light | Common laboratory practice |
| Analytical method | LC-MS/MS | Detects parent compound and metabolites |
| Common test matrix | Urine or blood | Used in anti-doping analysis |
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.
Cardarine is a common name for GW501516, also GW-1516, a synthetic compound developed as a peroxisome proliferator-activated receptor delta (PPARδ) agonist. It belongs to a class of agents that modulate gene transcription related to lipid and energy metabolism. The compound was studied in preclinical and early clinical research for metabolic and cardiovascular conditions, but it did not progress to approved therapeutic use. Its name appears in fitness and sports contexts despite not being approved as a drug.
PPARδ is a nuclear receptor that influences transcription of genes involved in fatty acid oxidation, lipid transport, and energy homeostasis. GW501516 binds and activates this receptor with high selectivity relative to PPARα and PPARγ in laboratory assays. Activation alters expression of target genes in skeletal muscle, liver, and adipose tissue in animal models. The exact clinical consequences of these changes in humans remain incompletely characterized, and observed effects in animals do not establish therapeutic benefit or safety.
== Advocacy == AMP advocates for molecular professionals and the patients they serve. In the U.S. molecular genetics testing is governed by a wide range of regulations, including the Clinical Laboratory Improvement Act (CLIA), the Centers for Medicare and Medicaid, and the Food and Drug Administration, that impact the performance and reimbursement of medical laboratory services. Through its advocacy efforts, such as the AMP Economics Summit, AMP strives to modernize the regulatory environment. It works to inform the U.S. Congress and federal agencies regarding public policy issues affecting molecular pathology. AMP seeks to shape and promote policies that ensure broad and equitable patient access to appropriate laboratory testing. Internationally, AMP members are involved in advocating for appropriate molecular diagnostic testing in several countries around the world.
=== Further reading === Philip J. Kocieński: Protecting Groups, 1st ed., Georg Thieme Verlag, Stuttgart 1994, ISBN 3-13-135601-4. Peter G.M. Wuts, Theodora W. Greene: Green's Protective Groups in Organic Synthesis, 4th Ed., John Wiley & Sons Inc., Hoboken, New Jersey, ISBN 0-471-69754-0. Michael Schelhaas, Herbert Waldmann: "Schutzgruppenstrategien in der organischen Synthese", in: Angewandte Chemie, 1996, 103, pp. 2192–2219; doi:10.1002/ange.19961081805 (in German). Krzysztof Jarowicki, Philip Kocieński: "Protecting groups", in: J. Chem. Soc., Perkin Trans. 1, 1998, pp. 4005–4037; doi:10.1039/A803688H.
Legal opium importation from India and Turkey is conducted by Mallinckrodt, Noramco, Abbott Laboratories, Purdue Pharma, and Cody Laboratories Inc. in the United States, and legal opium production is conducted by GlaxoSmithKline, Johnson & Johnson, Johnson Matthey, and Mayne in Tasmania, Australia; Sanofi Aventis in France; Shionogi Pharmaceutical in Japan; and MacFarlan Smith in the United Kingdom. Under the international drug control system, International Narcotics Control Board monitoring is based primarily on information submitted by governments, including annual statistical reports, estimates and assessments, and official communications; the Board uses this process to assess global, regional and national trends and evaluate national control measures. In 2005, the European Senlis Council began developing a programme which hopes to solve the problems caused by the large quantity of opium produced illegally in Afghanistan, most of which is converted to heroin and smuggled for sale in Europe and the United States. This proposal is to license Afghan farmers to produce opium for the world pharmaceutical market, and thereby solve another problem, that of chronic underuse of potent analgesics where required within developing nations. Part of the proposal is to overcome the "80–20 rule" that requires the U.S.
Sources: en.wikipedia.org
"Like typical metals, it [astatine] is precipitated by hydrogen sulfide even from strongly acid solutions and is displaced in a free form from sulfate solutions; it is deposited on the cathode on electrolysis." Further indications of a tendency for astatine to behave like a (heavy) metal are: "... the formation of pseudohalide compounds ... complexes of astatine cations ... complex anions of trivalent astatine ... as well as complexes with a variety of organic solvents". It has also been argued that astatine demonstrates cationic behaviour, by way of stable At+ and AtO+ forms, in strongly acidic aqueous solutions. Some of astatine's reported properties are nonmetallic. It has been extrapolated to have the narrow liquid range ordinarily associated with nonmetals (mp 302 °C; bp 337 °C), although experimental indications suggest a lower boiling point of about 230±3 °C. Batsanov gives a calculated band gap energy for astatine of 0.7 eV; this is consistent with nonmetals (in physics) having separated valence and conduction bands and thereby being either semiconductors or insulators. The chemistry of astatine in aqueous solution is mainly characterised by the formation of various anionic species. Most of its known compounds resemble those of iodine, which is a halogen and a nonmetal. Such compounds include astatides (XAt), astatates (XAtO3), and monovalent interhalogen compounds. Restrepo et al. reported that astatine appeared to be more polonium-like than halogen-like.
== Personal life == In January 2025, Heppell married his long-time partner, Kate. The couple hyphenated their surname to Turner-Heppell to acknowledge Kate's maiden name. In November and December 2025, Dyson competed on the twelfth season of I'm a Celebrity...Get Me Out of Here!, which began airing on January 18, 2026. He was eliminated on February 11, 2026 after 15 days in the jungle.
=== United Kingdom === In the United Kingdom, the Medicines Act 1968 and the Prescription Only Medicines (Human Use) Order 1997 contain regulations that cover the supply of sale, use, prescribing and production of medicines. There are three categories of medicine:
Sources: en.wikipedia.org
Anti-doping and clinical laboratories commonly use liquid chromatography-tandem mass spectrometry. The method can identify GW501516 and its metabolites in urine or blood. Detection depends on sample timing and the amount present.
PPARδ is a nuclear receptor that regulates genes linked to fatty acid oxidation and energy metabolism. Activation can alter lipid handling and energy use in experimental models. The full range of effects in humans is still under study.
The solid compound is generally stable when kept cold, dry, and protected from light. Solutions may degrade faster, so laboratory protocols often specify fresh preparation or cold storage. Stability can depend on solvent, concentration, and container.
Legal status varies by country, but cardarine is not approved as a medicine in major jurisdictions. It is often sold as a research chemical, a category that may not be lawful for human use. Buyers should check local laws and product labels carefully.