GW501516 is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-06-09. 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 developed in the 1990s through research collaborations involving GlaxoSmithKline. It belongs to a class of molecules known as peroxisome proliferator-activated receptor delta agonists. Early studies explored its effects on lipid metabolism and energy expenditure in animal models. The compound was never approved as a human medicine, and clinical development was discontinued. In the years since, it has appeared in fitness and bodybuilding communities as a performance-enhancing substance. Regulatory agencies classify it as an unapproved drug.
PPARδ is a nuclear receptor that regulates gene expression related to fatty acid oxidation, glucose homeostasis, and mitochondrial function. GW501516 binds to this receptor with high affinity and activates downstream signaling in skeletal muscle and other tissues. Animal studies reported increased endurance and altered fuel preference, but human data remain limited and inconsistent. The precise relationship between receptor activation and observed physiological changes is still an area of active investigation. Researchers have also examined whether the compound affects inflammation or cell proliferation. No approved therapeutic indication exists for cardarine.
In laboratory settings, cardarine is studied as a tool compound for probing PPARδ biology. Published experiments often use cell cultures, rodent models, or isolated tissues. Some investigations focus on metabolic effects, while others assess potential risks such as carcinogenicity observed in long-term animal studies. Because human trials are sparse, most knowledge comes from preclinical work and adverse event reports. Scientific literature frequently notes the gap between animal findings and human outcomes. The compound is not a dietary supplement and is not intended for human consumption.
GW501516 acts on PPARδ, a nuclear receptor that helps regulate fatty acid oxidation and energy homeostasis. In animal studies, activation of this receptor was associated with increased endurance and changes in lipid metabolism. Human trials examined effects on blood lipids and other metabolic markers, but the compound did not advance to approval. Rodent studies later reported tumors in multiple tissues at doses used in those experiments. Whether those findings translate to human risk remains uncertain, and the clinical relevance of the animal data is still debated.
Regulatory bodies treat GW501516 as a prohibited substance in competitive sport. The World Anti-Doping Agency added it to the prohibited list, and it falls under classes covering metabolic modulators and hormone-related agents. It is not approved by drug regulators for human use, and it is not a lawful dietary supplement. Products sold under the cardarine name may contain unlisted ingredients or different compounds. Because no approved product exists, quality and identity are not guaranteed by pharmaceutical manufacturing standards.
| Property | Value | Notes |
|---|---|---|
| CAS Registry Number | 317318-70-0 | Unique identifier for the compound. |
| Chemical class | PPARδ agonist | Synthetic ligand for peroxisome proliferator-activated receptor delta. |
| Appearance | White to off-white solid | Typical form of research-grade material. |
| Solubility | Soluble in DMSO and ethanol | Poorly soluble in water. |
| Typical storage | -20°C | Recommended for long-term storage of stock solutions. |
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.
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.
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.
Products sold as cardarine have been found to contain incorrect compounds, variable amounts, or no active ingredient at all. Independent testing is required to verify identity and purity. Common analytical approaches include high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance for structural confirmation. These methods can distinguish GW501516 from related PPAR agonists and from unrelated steroids. For regulators and researchers, such verification is central to interpreting both biological results and adverse event reports.
Handling and quality assessment of cardarine reference material follow general laboratory practices for poorly characterized compounds. It typically appears as a white to off-white powder and is sparingly soluble in water but soluble in organic solvents such as dimethyl sulfoxide and ethanol. Storage recommendations usually specify a cool, dry, dark place, with long-term storage at low temperature and desiccation. Purity may be checked by high-performance liquid chromatography with ultraviolet detection, while identity is confirmed by mass spectrometry and nuclear magnetic resonance. No pharmacopeial monograph exists, so reported purity and stability depend on the supplier’s methods.
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.
== Business model == Pilot is a vertical integration telehealth company that offers specific treatments for specific ailments. Patients complete an online assessment and pay a fee to Pilot to talk to a doctor. If treatment is recommended, the patient signs up for a monthly subscription. Medication is delivered to their specified address. Pilot acts as a wholesaler of Schedule 4 medications. Medications are supplied via partner pharmacies. In most cases, they do not offer items available through Medicare or the Pharmaceutical Benefits Scheme (PBS).
HDC plays an especially important role in the field of microfluidics. The first successful apparatus for HDC-on-a-chip system was proposed by Chmela, et al. in 2002. Their design was able to achieve separations using an 80 mm long channel on the timescale of 3 minutes for particles with diameters ranging from 26 to 110 nm, but the authors expressed a need to improve the retention and dispersion parameters. In a 2010 publication by Jellema, Markesteijn, Westerweel, and Verpoorte, implementing HDC with a recirculating bidirectional flow resulted in high resolution, size based separation with only a 3 mm long channel. Having such a short channel and high resolution was viewed as especially impressive considering that previous studies used channels that were 80 mm in length. For a biological application, in 2007, Huh, et al. proposed a microfluidic sorting device based on HDC and gravity, which was useful for preventing potentially dangerous particles with diameter larger than 6 microns from entering the bloodstream when injecting contrast agents in ultrasounds. This study also made advances for environmental sustainability in microfluidics due to the lack of outside electronics driving the flow, which came as an advantage of using a gravity based device.
Hanisch published a paper describing "A Method for Preparing Testosterone from Cholesterol." Only a week later, the third group, Ruzicka and A. Wettstein, announced a patent application in a paper "On the Artificial Preparation of the Testicular Hormone Testosterone (Androsten-3-one-17-ol)." Ruzicka and Butenandt were offered the 1939 Nobel Prize in Chemistry for their work, but the Nazi government forced Butenandt to decline the honor, although he accepted the prize after the end of World War II. Clinical trials on humans, involving either PO doses of methyltestosterone or injections of testosterone propionate, began as early as 1937. There are often reported rumors that German soldiers were administered AAS during the Second World War, the aim being to increase their aggression and stamina, but these are, as yet, unproven. Adolf Hitler himself, according to his physician, was injected with testosterone derivatives to treat various ailments. AAS were used in experiments conducted by the Nazis on concentration camp inmates, and later by the allies attempting to treat the malnourished victims that survived Nazi camps. President John F. Kennedy was administered steroids both before and during his presidency.
==== Lawsuit ==== Robinson responded to the dismissal by charging that he, not Pauling, had done the experimental work at the institute, and that "Linus has not personally contributed significant research work on vitamin C and human health". Robinson filed a lawsuit against the Institute for $25.5 million, finally settling for $575,000.
Sources: en.wikipedia.org
Flip–flop kinetics, or flip–flop pharmacokinetics, describes an atypical situation in pharmacokinetics where a drug's rate of absorption or the rate at which it enters the bloodstream is slower than its elimination rate. That is, when the ka (absorption constant) is slower than ke (elimination constant). These circumstances can occur with sustained-release formulations, depot injections, and some subcutaneous or intradermal injections. In the resulting slope of log plasma concentration (log Cp) versus time, the apparent ke is determined by the ka, and the apparent ke is smaller than when the drug is administered intravenously or by immediate-release formulation. Depot injections such as depot antipsychotics and long-acting injectable steroid hormone medications like estradiol valerate, testosterone enanthate, and medroxyprogesterone acetate are examples of drugs with flip–flop kinetics. The term "flip–flop" indicates that the downward slope more closely represents ka rather than ke. Flip–flop kinetics can create difficulties in the determination and interpretation of pharmacokinetic parameters if not recognized.
Globin proteins and thus their genes have an ancient evolutionary origin. Even plants have a form of globin called leghemoglobin which shares about 15% of its sequence with hemoglobin. While this level of similarity may be caused by chance, the 3-dimensional structure of both proteins is so similar that it is commonly assumed that they have a common origin. This is confirmed by the conservation of intron positions in both types of genes. Variations in hemoglobin sequences, as with other proteins, may be adaptive. For example, hemoglobin has been found to adapt in different ways to the thin air at high altitudes, where lower partial pressure of oxygen diminishes its binding to hemoglobin compared to the higher pressures at sea level. Recent studies of deer mice found mutations in four genes that can account for differences between high- and low-elevation populations. It was found that the genes of the two breeds are "virtually identical—except for those that govern the oxygen-carrying capacity of their hemoglobin. . . . The genetic difference enables highland mice to make more efficient use of their oxygen."
A brand extension, combining the TGI Fridays concept with the atmosphere of a sports bar, called "Fridays Front Row Sports Grill", is found at two Major League Baseball stadiums which each overlook the playing field: Chase Field in Phoenix, Arizona and Miller Park in Milwaukee. There was also a Friday's Front Row Grill for a few seasons at Globe Life Park, then the Texas Rangers home field.
Aminopeptidase regulator of tumour necrosis factor receptor 1 (TNFR1) shedding (ARTS-1) Adipocyte-derived leucine aminopeptidase (A-LAP) Puromycin-insensitive leucyl-specific aminopeptidase (PILS-AP) KIAA0525 In mice, ER aminopeptidase associated with antigen processing (ERAAP)
R-NH2 + DBNPA → R-NH-C(Br)(NO2)NH2 In basic environments, DBNPA undergoes nucleophilic substitution by hydroxide ions, which initiates hydrolysis. This reaction reduces the environmental persistence of DBNPA by breaking it down into smaller degradation products.
Sources: en.wikipedia.org
== Translational readthrough == Stop codon suppression or translational readthrough occurs when in translation a stop codon is interpreted as a sense codon, that is, when a (standard) amino acid is 'encoded' by the stop codon. Mutated tRNAs can be the cause of readthrough, but also certain nucleotide motifs close to the stop codon. Translational readthrough is very common in viruses and bacteria, and has also been found as a gene regulatory principle in humans, yeasts, bacteria and drosophila. This kind of endogenous translational readthrough constitutes a variation of the genetic code, because a stop codon codes for an amino acid. In the case of human malate dehydrogenase, the stop codon is read through with a frequency of about 4%. The amino acid inserted at the stop codon depends on the identity of the stop codon itself: Gln, Tyr, and Lys have been found for the UAA and UAG codons, while Cys, Trp, and Arg for the UGA codon have been identified by mass spectrometry. Extent of readthrough in mammals have widely variable extents, and can broadly diversify the proteome and affect cancer progression.
An offshoot of the Zulu, the amaNdebele, better known to history as the Matabele, created an even larger empire under their king Mzilikazi, including large parts of the highveld and modern-day Zimbabwe.
Purification in a chemical context is the physical separation of a chemical substance of interest from foreign or contaminating substances. Pure results of a successful purification process are termed isolate. The following list of chemical purification methods should not be considered exhaustive.
== Carbon capture and storage == Typical adsorbents proposed for carbon capture and storage are zeolites and MOFs. The customization of adsorbents makes them a potentially attractive alternative to absorption. Because adsorbents can be regenerated by temperature or pressure swing, this step can be less energy intensive than absorption regeneration methods. Major problems that are present with adsorption cost in carbon capture are: regenerating the adsorbent, mass ratio, solvent/MOF, cost of adsorbent, production of the adsorbent, lifetime of adsorbent. In sorption enhanced water gas shift (SEWGS) technology a pre-combustion carbon capture process, based on solid adsorption, is combined with the water-gas shift reaction (WGS) in order to produce a high pressure hydrogen stream. The CO2 stream produced can be stored or used for other industrial processes.
Sources: en.wikipedia.org
Cardarine is a common name for GW501516, a synthetic PPARδ agonist developed for research. It has not been approved as a medication in any country. It is classified as an unapproved drug and a prohibited substance in sport.
No. Cardarine is not an anabolic steroid; it belongs to a different chemical class that targets PPARδ. Steroids act primarily through androgen receptors, while cardarine acts through a nuclear receptor involved in metabolism.
Some rodent studies reported increased endurance and changes in fat metabolism after cardarine exposure. Long-term studies in animals also raised concerns about cancer in certain tissues. Human trial data are limited, so these findings cannot be directly translated to people.
No. Cardarine is a PPARδ agonist, while selective androgen receptor modulators act on androgen receptors. The two classes differ in receptor target and downstream effects.