PPAR delta 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 2026-01-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
Cardarine is a common name for GW501516, a synthetic compound studied for its effects on lipid and glucose metabolism. It functions as an agonist at peroxisome proliferator-activated receptor delta, or PPARδ, a nuclear receptor that influences gene expression. The molecule is not a steroid, nor is it a selective androgen receptor modulator. It is also known in research and sports literature as GW-501516 and endurobol. Early laboratory work examined its metabolic activity in cell cultures and animal models.
Activation of PPARδ changes transcription of genes involved in fatty acid transport, mitochondrial function, and skeletal muscle fuel preference. In rodent studies, pharmacological PPARδ activation was associated with increased endurance and altered body composition. These findings generated interest in performance enhancement, but species differences and study designs limit direct extrapolation to humans. Small human trials were conducted in the 2000s and later discontinued. The extent to which cardarine produces similar metabolic or performance effects in people remains an open question.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic PPARδ agonist | Not a steroid or a selective androgen receptor modulator. |
| Common synonyms | Cardarine, GW501516, GW-501516, endurobol | Names vary by supplier and literature source. |
| Appearance | White to off-white powder | Consistent with many small-molecule research chemicals. |
| Solubility | Low in water; soluble in DMSO and ethanol | Often prepared in organic solvent for laboratory work. |
| Primary target | PPARδ (NR1C2) | Nuclear receptor involved in lipid and energy metabolism. |
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 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.
=== Gene regulation === Crystallin recruitment may occur by changes in gene regulation that leads to high lens expression. One such example is gluthathione S-transferase/S11-crystallin that was specialized for lens expression by change in gene regulation and gene duplication. The fact that similar transcriptional factors such as Pax-6, and retinoic acid receptors, regulate different crystalline genes, suggests that lens-specific expression have played a crucial role for recruiting multifunctional protein as crystallins. Crystallin recruitment has occurred both with and without gene duplication, and tandem gene duplication has taken place among some of the crystallins with one of the duplicates specializing for lens expression. Ubiquitous α –crystallins and bird δ –crystallins are two examples.
=== 1977–1981: Peak progressive era === After the conclusion of the 2112 tour, Rush recorded A Farewell to Kings (1977) and Hemispheres (1978) at Rockfield Studios in Monmouthshire, Wales. The albums had the band members expanding the progressive elements in their music. "As our tastes got more obscure", Lee said in an interview, "we discovered more progressive rock-based bands like Yes, Van der Graaf Generator, and King Crimson, and we were very inspired by those bands. They made us want to make our music more interesting and more complex, and we tried to blend that with our own personalities to see what we could come up with that was indisputably us." Increased synthesizer use, lengthy songs, and highly dynamic playing featuring complex time signature changes became a staple of Rush's compositions. To achieve a broader, more progressive sound, Lifeson began to experiment with classical and twelve-string guitars, and Lee added bass-pedal synthesizers and Minimoog. Likewise, Peart's percussion became diversified in the form of triangles, glockenspiel, wood blocks, cowbells, timpani, gong, and chimes. Beyond instrument additions, the band kept in stride with progressive rock trends by continuing to compose long, conceptual songs with science fiction and fantasy overtones. As the new decade approached, Rush gradually began to dispose of their older styles of music in favour of shorter and sometimes softer arrangements, due in part to the band's exhaustion from recording Hemispheres.
== Nutritional deficiencies (260–269) == 260 Kwashiorkor 261 Nutritional marasmus 262 Other severe protein–calorie malnutrition 263 Other and unspecified protein–calorie malnutrition 264 Vitamin A deficiency 264.0 With conjunctival xerosis 264.1 With conjunctival xerosis and Bitot's spot 264.2 With corneal xerosis 264.3 With corneal ulceration and xerosis 264.4 With keratomalacia 264.5 With night blindness 264.6 With xerophthalmic scars of cornea 264.7 Other ocular manifestations of vitamin A deficiency 264.8 Other manifestations of vitamin A deficiency 264.9 Unspecified vitamin A deficiency 265 Thiamine and niacin deficiency states 265.0 Beriberi 265.1 Other and unspecified manifestations of thiamine deficiency Wernicke's encephalopathy 265.2 Pellagra 266 Deficiency of B-complex components 266.0 Ariboflavinosis 266.2 B12 deficiency w/o anemia 267 Ascorbic acid deficiency 268 Vitamin D deficiency 269 Other nutritional deficiencies 269.0 Deficiency of vitamin K 269.1 Deficiency of other vitamins 269.2 Unspecified vitamin deficiency 269.3 Mineral deficiency, not elsewhere classified
Supervised injection sites (SIS), or Drug consumption rooms (DCR), are legally sanctioned, medically supervised facilities designed to address public nuisance associated with drug use and provide a hygienic and stress-free environment for drug consumers. The facilities provide sterile injection equipment, information about drugs and basic health care, treatment referrals, and access to medical staff. Some offer counseling, hygienic and other services of use to itinerant and impoverished individuals. Most programmes prohibit the sale or purchase of illegal drugs. Many require identification cards. Some restrict access to local residents and apply other admission criteria, such as they have to be people who inject substances, but generally in Europe they do not exclude people with substance use disorders who consume their substances through other means. The Netherlands had the first staffed injection room, although they did not operate under explicit legal support until 1996. Instead, the first center where it was legal to inject drugs was in Berne, Switzerland, opened 1986. In 1994, Germany opened its first site. Although, as in the Netherlands they operated in a "gray area", supported by the local authorities and with consent from the police until the Bundestag provided a legal exemption in 2000. In Europe, Luxembourg, Spain and Norway have opened facilities after year 2000. Sydney's Medically Supervised Injecting Center (MSIC) was established in May 2001 as a trial and Vancouver's Insite opened in September 2003.
Sources: en.wikipedia.org
isomerase Any of a class of enzymes which catalyze the conversion of a molecule from one isomer to another, such that the product of the reaction has the same molecular formula as the original substrate but differs in the connectivity or spatial arrangement of its atoms.
=== Historical perspective === To date, over 20 different secondary structure prediction methods have been developed. One of the first algorithms was Chou–Fasman method, which relies predominantly on probability parameters determined from relative frequencies of each amino acid's appearance in each type of secondary structure. The original Chou-Fasman parameters, determined from the small sample of structures solved in the mid-1970s, produce poor results compared to modern methods, though the parameterization has been updated since it was first published. The Chou-Fasman method is roughly 50–60% accurate in predicting secondary structures. The next notable program was the GOR method is an information theory-based method. It uses the more powerful probabilistic technique of Bayesian inference. The GOR method takes into account not only the probability of each amino acid having a particular secondary structure, but also the conditional probability of the amino acid assuming each structure given the contributions of its neighbors (it does not assume that the neighbors have that same structure). The approach is both more sensitive and more accurate than that of Chou and Fasman because amino acid structural propensities are only strong for a small number of amino acids such as proline and glycine. Weak contributions from each of many neighbors can add up to strong effects overall. The original GOR method was roughly 65% accurate and is dramatically more successful in predicting alpha helices than beta sheets, which it frequently mispredicted as loops or disorganized regions.
The park was closed for renovations on July 11, 1988. The four-year project to rebuild Bryant Park entailed new entrances, repairs to paths and lighting, and a redesign of the park's garden by Lynden Miller. Biederman worked with William H. Whyte, a sociologist whose influence led them to implement two decisions. One was the placement of 2,000 movable chairs in the park. The other was to lower the park itself, because Bryant Park had been elevated from the street and isolated by tall hedges prior to the 1988 redesign. The 1988 renovation lowered the park to nearly street level and tore out the hedges, though much of the park was still slightly elevated. The park's restrooms, which had been closed for 35 years, were renovated as well. The BPRC also found that several of the sculptures would need to be repaired, and called on William Cullen Bryant's descendants and other entities to provide funding for the restoration of these sculptures. Landscape architect Laurie Olin of Hanna/Olin recalls that the design process focused on "the different abilities of people [who] use these spaces...as well as making spaces that people are comfortable being with each other in." The restoration cost $8.9 million, which included $5.7 million of city funding and $3.2 million of private funding. The renovation took place at the same time as the NYPL's expansion of the main branch's stacks underneath Bryant Park.
Sources: en.wikipedia.org
The Victorian College of the Arts (VCA) is the arts school at the University of Melbourne in Australia. It is part of the university's Faculty of Fine Arts and Music (FFAM). It is located near the Melbourne city centre on the Southbank campus of the university. The VCA Film and Television School was founded in 1991, after it assumed ownership and management of the Swinburne Film and Television School. Courses and training offered at the VCA cover seventeen discipline areas: acting and theatre, composition, creative arts and music therapy, dance, design and production, ethnomusicology, film and television, Indigenous arts and culture, interactive composition, jazz and improvisation, music performance, music psychology, music theatre, musicology, performance teaching, visual art, and writing. The VCA is also home to the Wilin Centre for Indigenous Arts and Cultural Development. The library on the Southbank campus is known as the Lenton Parr Music, Visual and Performing Arts Library.
== DNA repair == Hydras are capable of two types of DNA repair: nucleotide excision repair and base excision repair. The repair pathways facilitate DNA replication by removing DNA damage. Their identification in Hydra was based, in part, on the presence in its genome of genes homologous to ones present in other genetically well studied species playing key roles in these DNA repair pathways.
=== Atomic and molecular physics === Some atomic energy levels are metastable. Rydberg atoms are an example of metastable excited atomic states. Transitions from metastable excited levels are typically those forbidden by electric dipole selection rules. This means that any transitions from this level are relatively unlikely to occur. In a sense, an electron that happens to find itself in a metastable configuration is trapped there. Since transitions from a metastable state are not impossible (merely less likely), the electron will eventually decay to a less energetic state, typically by an electric quadrupole transition, or often by non-radiative de-excitation (e.g., collisional de-excitation). This slow-decay property of a metastable state is apparent in phosphorescence, the kind of photoluminescence seen in glow-in-the-dark toys that can be charged by first being exposed to bright light. Whereas spontaneous emission in atoms has a typical timescale on the order of 10−8 seconds, the decay of metastable states can typically take milliseconds to minutes, and so light emitted in phosphorescence is usually both weak and long-lasting.
Sources: en.wikipedia.org
Cardarine is a common name for GW501516, a synthetic PPARδ agonist. It is not a steroid or a selective androgen receptor modulator. It was developed and studied as a research compound for metabolic pathways.
It binds to and activates PPARδ, a nuclear receptor that regulates genes related to fatty acid oxidation and energy use. This activation alters transcription in tissues such as skeletal muscle and liver. The full range of downstream effects in humans is not fully established.
No, cardarine is not known to occur naturally in plants, animals, or humans. It is a synthetic molecule produced for laboratory research. Products labeled as cardarine should therefore be treated as manufactured chemicals with variable purity.
It binds to and activates PPAR delta, a nuclear receptor that controls expression of genes related to fatty acid oxidation. This mechanism can alter energy metabolism in animal models. It is not a direct stimulant or fat-burning enzyme.