This is a working overview of PPARδ, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-10-13. Anything still debated is marked as such rather than presented as settled.
Cardarine is a synthetic compound also known as GW501516, GW-501516, and sometimes endurobol. It was developed as a selective agonist of peroxisome proliferator-activated receptor delta, a nuclear receptor involved in fatty acid oxidation and energy metabolism. The compound was studied in preclinical models for metabolic and cardiovascular conditions, but it did not become a marketed human medicine. In regulatory and anti-doping contexts, it is treated as a prohibited substance rather than a licensed medicine.
The pharmacological interest in cardarine centers on PPARδ activation and its downstream effects on lipid handling and mitochondrial function. In animal studies, PPARδ agonists have been associated with changes in exercise endurance and fatty acid utilization, though results vary by model and protocol. Human data remain sparse, and the absence of large controlled trials limits conclusions about efficacy. Researchers often describe the compound as a tool for probing PPARδ biology rather than a proven therapeutic agent.
Safety discussions about cardarine frequently cite rodent carcinogenicity findings reported in the 2000s. In those studies, treated animals developed tumors at multiple sites, leading sponsors to discontinue clinical development. The relevance of these findings to humans has not been resolved, but they are a major reason the compound is not approved. Current literature emphasizes uncertainty about long-term effects and the risks of unregulated use. Regulators and health agencies have not established a safe human exposure level.
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.
Laboratory handling focuses on identity, purity, and stability. Reference standards are typically stored cold and dry, protected from light, because solutions can degrade over time. Analytical checks may use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Impurities and related substances can be separated chromatographically and compared with a known standard. Because cardarine is not an approved drug, compendial monographs are absent, and laboratories often rely on in-house methods. Reported purity varies among unregulated products and should not be assumed from a label.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | GW501516, GW-501516, GW 501516, endurobol | Names vary in research and anti-doping documents. |
| Chemical class | Synthetic PPARδ agonist | Small-molecule nuclear receptor ligand. |
| CAS Registry Number | 317318-70-0 | Identifier commonly associated with GW501516. |
| Appearance | White to off-white powder | Typical for purified research material. |
| Solubility | Low in water; soluble in DMSO and ethanol | Organic solvents are common for laboratory stock solutions. |
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.
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.
=== Medical specialty === The beginning of psychiatry as a medical specialty is dated to the middle of the nineteenth century, although its germination can be traced to the late eighteenth century. In the late 17th century, privately run asylums for the insane began to proliferate and expand in size. In 1713, the Bethel Hospital Norwich was opened, the first purpose-built asylum in England. In 1656, Louis XIV of France created a public system of hospitals for those with mental disorders, but as in England, no real treatment was applied. During the Enlightenment, attitudes towards the mentally ill began to change. It came to be viewed as a disorder that required compassionate treatment. In 1758, English physician William Battie wrote his Treatise on Madness on the management of mental disorder. It was a critique aimed particularly at the Bethlem Royal Hospital, where a conservative regime continued to use barbaric custodial treatment. Battie argued for a tailored management of patients entailing cleanliness, good food, fresh air, and distraction from friends and family. He argued that mental disorder originated from dysfunction of the material brain and body rather than the internal workings of the mind.
== Techniques == There are a variety of approaches to studying topography. Which method(s) to use depends on the scale and size of the area under study, its accessibility, and the quality of existing surveys.
The common octopus (Octopus vulgaris) is a mollusk belonging to the class Cephalopoda. Octopus vulgaris is one of the most studied of all the octopus species, and also one of the most intelligent. It ranges from the eastern Atlantic, extends from the Mediterranean Sea, Black sea and the southern coast of England, to the southern coast of South Africa. It also occurs off the Azores, Canary Islands, and Cape Verde Islands. The species is also common in the Western Atlantic.
Sources: en.wikipedia.org
The binding of ibotenic acid allows excess Ca2+ into the system which results in neuronal cell death. Ca2+ also activates CaM-KII or Ca2+/Calmodulin Kinase which phosphorylates multiple enzymes. The activated enzymes then begin producing reactive oxygen species which damages surrounding tissue. The excess Ca2+ results in the enhancement of the mitochondrial electron transport system which will further increase the number of reactive oxygen species.
=== Names === Ritanserin is the generic name of the drug and its INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name, and BANTooltip British Approved Name. It is also known by its developmental code name R-55667.
=== Potato Sack === The Potato Sack was an A.R.G (alternate reality game) conceived by Valve and 13 indie video game developers as a prelude to the release of Portal 2. Portal 2 had been announced by a similar game, where a patch applied to the Steam version of Portal in March 2010, provided clues heralding the official announcement. The Potato Sack game, launched on April 1, 2011, led to the reveal of "GLaDOS@home", a spoof of distributed computer challenges, to get players to cooperate on playing the independent games as to unlock Portal 2 on Steam about 10 hours before its planned release.
Sources: en.wikipedia.org
=== Sidearms === Enfield No. 2 – In service early on in the Cold War. Webley Revolver – Substitute for Enfield No 2. Browning Hi-Power – Main sidearm during the Cold War. Walther PP - .32 ACP model issued to fast jet pilots, .22LR caliber model issued to the Ulster Defence Regiment as a personal protection weapon. SIG Sauer P226 - Special forces issue in the late 1980s Walther P5 - P5 Compact issued to the Royal Irish Regiment (Home Service) and Ulster Defence Regiment as a personal protection weapon in the 1980s, with a small number also being issued to special forces.
== See also == Dimethylaminoethylindole Dimethyltryptamine/harmine Dimethyltryptamine/β-carbolines List of psychoactive plants List of substances used in rituals Psychedelic replication Substituted tryptamine
** not really an RTG, the BES-5 Buk (БЭС-5) reactor was a fast reactor which used thermocouples based on semiconductors to convert heat directly into electricity *** not really an RTG, the SNAP-10A used enriched uranium fuel, zirconium hydride as a moderator, liquid sodium potassium alloy coolant, and was activated or deactivated with beryllium reflectors Reactor heat fed a thermoelectric conversion system for electrical production. **** not really an RTG, the ASRG uses a Stirling power device that runs on radioisotope (see Stirling radioisotope generator)
=== World production of ethylene oxide === The world production of ethylene oxide was 20 Mt (22 million short tons) in 2009, 19 Mt (21 million short tons) in 2008 and 18 Mt (20 million short tons) in 2007. This places ethylene oxide 14th most produced organic chemical, whereas the most produced one was ethylene with 113 Mt (125 million short tons). SRI Consulting forecasted the growth of consumption of ethylene oxide of 4.4% per year during 2008–2013 and 3% from 2013 to 2018. In 2004, the global production of ethylene oxide by region was as follows:
Sources: en.wikipedia.org
Cardarine is an investigational synthetic compound that acts as a PPARδ agonist. It is also known as GW501516 and has been studied mainly in preclinical research. It is not an approved medicine.
No. Cardarine is not a steroid hormone; it targets the nuclear receptor PPARδ. Its classification in anti-doping rules differs from anabolic steroids, though it remains prohibited in sport.
Early rodent studies reported tumor formation at multiple sites, which raised safety concerns. Sponsors stopped clinical development, and no approved human product exists.
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.