Everything below concerns LC-MS/MS. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-05-22. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
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.
Quality assessment for cardarine samples usually combines identity, purity, and impurity testing. Nuclear magnetic resonance spectroscopy and mass spectrometry can confirm molecular structure, while high-performance liquid chromatography estimates purity. Certificates of analysis from testing laboratories may list these results, but they do not establish safety or legality. In the absence of approved manufacturing, products sold online may contain the wrong compound, variable amounts, or unlisted contaminants. Independent verification is therefore central to analytical work and to interpreting any reported biological activity.
Laboratory detection of GW501516 commonly uses liquid chromatography coupled with tandem mass spectrometry. The method can identify the parent compound or its metabolites in urine and blood after sample cleanup. Protein precipitation, solid-phase extraction, or enzymatic hydrolysis may precede analysis, depending on the matrix. Reference standards are required for accurate quantification and confirmation. Because the compound is not approved, testing often occurs in anti-doping, forensic, or research settings rather than routine clinical care. Results are reported with limits of detection and quantification.
Stability of GW501516 depends on form, temperature, light exposure, and moisture. Solid reference material is typically stored frozen or refrigerated in a desiccator and protected from light. Solutions in organic solvents such as dimethyl sulfoxide are often kept frozen in aliquots to reduce freeze-thaw cycling. Aqueous solubility is low, so aqueous stock solutions can be difficult to prepare without cosolvents. Degradation may appear as changes in chromatographic purity or mass spectral signal. Stability studies are needed to establish shelf life for any specific preparation.
| 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. |
Published literature on cardarine includes in vitro assays, rodent experiments, and a small number of human studies. Reports describe effects on exercise capacity and lipid metabolism in animals, while human evidence is sparse. Many online descriptions present the compound as a proven endurance aid, a claim not supported by regulatory approval or large clinical trials. Analytical studies focus on identifying the parent compound and its metabolites in biological samples. Important uncertainties include species differences, dose-response relationships, and the relevance of rodent tumor findings to humans.
Cardarine is the common name for GW501516, a synthetic compound studied as a peroxisome proliferator-activated receptor delta agonist. Researchers developed it to explore treatments for lipid disorders and metabolic conditions. It is not an approved medicine in any country. Early clinical work examined changes in HDL cholesterol and triglycerides, but development was discontinued after animal studies raised concerns about cancer. The compound remains available as a research chemical and appears in discussions of performance enhancement.
Regulatory treatment of cardarine differs by context and jurisdiction. In competitive sport, the World Anti-Doping Agency lists PPARδ agonists, including GW501516, as prohibited at all times. Outside sport, it lacks approval as a prescription medicine in major drug markets, and products sold for human consumption may be treated as unapproved drugs. Some countries also restrict importation or sale through general consumer protection and medicines laws. These classifications affect availability, testing, and legal risk without establishing therapeutic value.
Because cardarine is not an approved medicine, no pharmacopeial monograph defines its identity, purity, or storage requirements. Laboratories typically rely on in-house methods and reference standards when testing materials labeled as GW501516. Certificates of analysis may report purity and identity for a specific batch, but their scope varies and they do not guarantee safety or legal status. Independent verification can include high-performance liquid chromatography, mass spectrometry, nuclear magnetic resonance, and elemental analysis. The distinction between research chemical labeling and human use is significant because quality standards and oversight differ.
Cardarine can be detected in biological samples and product materials using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The method separates compounds by chromatography and identifies them by mass-to-charge transitions, allowing low-level detection in urine or blood. Sample preparation often involves enzymatic hydrolysis, solid-phase extraction, or protein precipitation. Certified reference materials and isotope-labeled internal standards improve quantification. Detection windows depend on metabolism, matrix, and assay sensitivity, so no single universal window applies.
Literature on cardarine often separates receptor pharmacology from toxicology. Mechanistic papers describe PPARδ activation and gene expression changes, while safety assessments focus on carcinogenicity and species differences. Questions remain about whether rodent tumors arise through PPARδ-dependent or off-target mechanisms. Another open area is how human metabolism and exposure compare with those in animal studies. Analytical methods such as liquid chromatography–mass spectrometry are used to confirm identity in biological and product samples.
GW501516 acts as an agonist at the peroxisome proliferator-activated receptor delta, a nuclear receptor that regulates gene expression. Activation shifts transcription toward genes involved in fatty acid uptake, oxidation, and energy expenditure. The compound does not bind the androgen receptor and therefore differs from anabolic steroids and SARMs. In rodent models, this metabolic shift has been linked to increased running endurance and reduced fat accumulation. The exact downstream pathways in humans remain incompletely characterized.
Legumin is family of globular proteins obtained from beans, peas, lentils, vetches, hemp and other leguminous seeds. Garden peas are a common nutritional source for humans that contains legumin. Legumin is similar to the casein of mammalian milk and was called "vegetable casein" since it was considered analogous to the mammalian protein. The primary function of the legumin protein in seeds is storage. Legumin proteins are one of the main storage proteins of angiosperms and gymnosperms. Legumin is an insoluble hexameric conjugated protein with a high concentration of carbon and oxygen.
== Menu == Culver's menu consists of butter burgers, chicken sandwiches, chicken tenders, fish, salads, soup, onion rings, french fries, cheese curds, and corn dogs. For dessert, the restaurant offers its frozen custard, served in either a dish, cone, or blended into a concrete mixer, malt, or shake. The company released an April Fools' joke in 2021 showing a large fried cheese curd in a burger bun, naming it the CurderBurger. Soon after the post was made, a change.org petition was created to make the burger a reality, gathering over 600 signatures. In celebration of National Cheese Curd Day on October 15 that year, the CurderBurger debuted, consisting of a large cheese curd on top of a burger patty. Each location only got a limited number of cheese curd patties, and all Madison, Wisconsin restaurants sold out before noon.
== Partnerships and Agreements == Licensing agreements for Biomatrica technologies were signed with Qiagen in 2007 and 2009. Following the launch of DNAstable, the company gained the interest of law enforcement organizations, such as the California Department of Justice, which sought to stabilize DNA samples from crime scenes for forensics purposes. Other law enforcement organizations, including sheriffs’ departments in Orange County, CA Los Angeles, CA, and Palm Beach, FL, have adopted ambient temperature forensic sample management systems based on Biomatrica's technologies. Also in 2010, Biomatrica signed a collaborative research and development agreement (CRADA) with United States Army Medical Research Institute for Infectious Diseases (USAMRIID) to develop and test new technologies for ambient temperature stabilization of clinical and biological samples. The same year, Biomatrica began a partnership agreement with the U.S. National Cancer Institute (NCI) for biomarker stabilization and SAIC-Frederick to improve molecular analysis of tumors. In 2011, the company announced a partnership agreement with In-Q-Tel, an investment firm that identifies technologies to support the mission of the U.S. intelligence community. In 2014, Biomatrica and American Type Tissue Culture (ATCC) signed a licensing agreement for Biomatrica to supply its DNA & RNA stabilization reagents to the ATCC for use in the latter company's DNA and RNA standards. In the same year, Biomatrica and Sigma-Aldrich signed an agreement for the worldwide distribution of Biomatrica's stabilization reagents.
== Biological role == It was not recognized until the 1970s, but nickel is known to play an important role in the biology of some plants, bacteria, archaea, and fungi. Nickel enzymes such as urease are considered virulence factors in some organisms. Urease catalyzes hydrolysis of urea to form ammonia and carbamate. NiFe hydrogenases can catalyze oxidation of H2 to form protons and electrons; and also the reverse reaction, the reduction of protons to form hydrogen gas. A nickel-tetrapyrrole coenzyme, cofactor F430, is present in methyl coenzyme M reductase, which can catalyze the formation of methane, or the reverse reaction, in methanogenic archaea (in +1 oxidation state). One of the carbon monoxide dehydrogenase enzymes consists of an Fe-Ni-S cluster. Other nickel-bearing enzymes include a rare bacterial class of superoxide dismutase and glyoxalase I enzymes in bacteria and several eukaryotic trypanosomal parasites (in other organisms, including yeast and mammals, this enzyme contains divalent Zn2+). Dietary nickel may affect human health through infections by nickel-dependent bacteria, but nickel may also be an essential nutrient for bacteria living in the large intestine, in effect functioning as a prebiotic. The US Institute of Medicine has not confirmed that nickel is an essential nutrient for humans, so neither a Recommended Dietary Allowance (RDA) nor an Adequate Intake have been established. The tolerable upper intake level of dietary nickel is 1 mg/day as soluble nickel salts. Estimated dietary intake is 70 to 100 μg/day; less than 10% is absorbed.
Copurification in a chemical or biochemical context is the physical separation by chromatography or other purification technique of two or more substances of interest from other contaminating substances. For substances to co-purify usually implies that these substances attract each other to form a non-covalent complex such as in a protein complex. However, when fractionating mixtures, especially mixtures containing large numbers of components (for example a cell lysate), it is possible by chance that some components may copurify even though they don't form complexes. In this context the term copurification is sometimes used to denote when two biochemical activities or some other property are isolated together after purification but it is not certain if the sample has been purified to homogeneity (i.e., contains only one molecular species or one molecular complex). Hence these activities or properties are likely but not guaranteed to reside on the same molecule or in the same molecular complex.
Sources: en.wikipedia.org
== History == Xylazine was discovered as an antihypertensive agent in 1962 by Farbenfabriken Bayer in Leverkusen, West Germany. In human trials xylazine was found to depress the central nervous system leading to the discontinuation of further research for its use in humans and it was instead marketed as a veterinary sedative, starting in the late 1960s. Xylazine proved popular and in the 1970s became one of the most common large animal sedatives. Xylazine's muscle relaxant effect inhibits the transmission of neural impulses in the central nervous system. In 1981 a study discovered that the cause sedation was due to xylazine's effect on the α2-adrenergic receptor. This led to the development of other α2-adrenergic receptor agonists such as detomidine, medetomidine, dexmedetomidine, and romifidine. In the United States, xylazine was approved by the FDA only for veterinary use as a sedative, analgesic, and muscle relaxant in dogs, cats, horses, elk, fallow deer, mule deer, sika deer, and white-tailed deer. In scientific research using animal experiments, xylazine is a component of the most common anesthetic, ketamine-xylazine (see: Rodent cocktail), to anesthetize rats, mice, hamsters, and guinea pigs. Xylazine has not previously been a controlled substance; however, due to illicit abuse, legislative restrictions have been proposed in multiple countries. Xylazine was made a class C drug in the UK on 15 January 2025.
In particular, VADAR’s secondary structure assignments appear to agree more closely with secondary structures identified by visual inspection (i.e. author assignments), by STRIDE (another secondary structure assignment algorithm) or via independent methods (i.e. NMR-based NOE methods).
=== Litigation === In 1965, the Banaban islanders, after decades of land disputes, royalty fees, and "exploitation," started legal litigation against the British Phosphate Commissioners in British court. After more than a decade, the case finally came to an end, with the Banabans only being awarded £1 and were still made to pay their own legal fees of more than £300,000. The Australian government through the B.P.C. offered £780,000 in reparations.
=== Extraction and purification === Throughout history, extraction and purification methods have evolved from standard chromatographic methods to the utilisation of affinity tags. However, the final extraction and purification process undertaken highly depends on the chosen expression system. Please refer to subunit expression and synthesis for more insights.
== Structure == The edited sites are found within the insulin growth factor binding domain of IGFBP7 and also Heparin binding domain. This region is also a site for proteolytic cleavage. Structural analysis of the edited sites determined that the two amino acids that corresponded to the edited sites are not directly involved in binding to IGF-1 but are found in regions flanking them. At position 78 in unedited version of the transcript there is an Arginine close to residue valine-49. This Valine is important in hydrophobic interaction of Phenylalanine of IGF-1. A substitution to a Glycine at this position is thought to introduce additional flexibility leading to a change of loop conformation, thereby disrupting the hydrophobic interaction that stabilises the complex. At amino acid position 98 the unedited transcript contains a lysine. This residue makes some non specific interactions via the aliphatic part of the side chain with Glu-38 of IGF-1. In the edited version the position is an arginine. The long side chain of which is thought to be able to maintain these weak interactions.
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.
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.