Anti-doping 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.
Updated 2026-01-04. Numbers and descriptions here follow the published literature rather than marketing material.
Laboratory studies have examined GW501516 in cell cultures and rodents for conditions such as dyslipidemia, insulin resistance, and obesity. Some trials in humans were initiated, but development was discontinued after preclinical findings raised concerns about cancer in certain models. Those findings do not prove that the compound causes cancer in people, but they contributed to regulatory caution. Later reviews often describe the evidence as preliminary and insufficient for assessing long-term safety.
In the fitness and bodybuilding literature, cardarine is frequently discussed as an endurance agent or fat-loss compound, although such claims are not supported by robust clinical evidence. Online descriptions often mix animal data, user anecdotes, and marketing language. Researchers who study PPARδ agonists distinguish between receptor activation in controlled experiments and unsupervised use of unverified products. The latter introduces unknown purity, dose, and interactions, making reported experiences difficult to interpret scientifically.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Solubility | Soluble in dimethyl sulfoxide and some organic solvents; practically insoluble in water | Solvent choice affects laboratory handling |
| Typical storage | -20 °C, desiccated, protected from light | Common condition for research samples |
| Analytical method | Liquid chromatography–tandem mass spectrometry (LC-MS/MS) | Used for identification and quantification in biological or product samples |
| Common synonyms | GW501516, GW-501516, GSK-516, Endurobol | Names found in research and anti-doping literature |
| Regulatory status | Unapproved therapeutic; prohibited in competitive sport | Status can vary by country and context |
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.
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 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.
== Reactions == Piperidine is widely used to convert ketones to enamines. Enamines derived from piperidine are substrates in the Stork enamine alkylation reaction. Upon treatment with calcium hypochlorite, piperidine converts to N-chloropiperidine, a chloramine with the formula C5H10NCl. The resulting chloramine undergoes dehydrohalogenation to afford the cyclic imine.
As shown by Lütge, Pikor, and Ludewig (2021), reticular cells in secondary lymphoid organs are not a single homogeneous group of cells, but instead consist of many subtypes of cells defined by their position in the body and expression of cell markers such as podoplanin and ER-TR7.
Furthermore, possible recognition sequences for furin (a major physiological protease) cleavage sites have been found in both amino-terminal NC1 domain and carboxyl-terminal NC4 domain of each one of these collagens. The activity of this protease is vital to explain the origin of the two forms that collagen types XIII, XXIII and XXV can adopt.
== Production == Putrescine is produced on an industrial scale by the hydrogenation of succinonitrile. Biotechnological production of putrescine from a renewable feedstock has been investigated. A metabolically engineered strain of Escherichia coli that produces putrescine at high concentrations in glucose mineral salts medium has been described.
The approval was based on comparisons of extensive structural and functional product characterization, animal data, human pharmacokinetic, clinical immunogenicity, and other clinical data demonstrating that Herzuma is biosimilar to US Herceptin. Herzuma has been approved as a biosimilar, not as an interchangeable product. Kanjinti was authorized for medical use in the European Union in May 2018. Trazimera was authorized for medical use in the European Union in July 2018. Ogivri was approved for medical use in Canada in May 2019. Trazimera was approved for medical use in Canada in August 2019. Herzuma was approved for medical use in Canada in September 2019. Kanjinti was approved for medical use in Canada in February 2020. Zercepac was authorized for medical use in the European Union in July 2020. Trastucip and Tuzucip were approved for medical use in Australia in July 2022. In September 2023, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Herwenda, intended for the treatment of HER2-positive breast and gastric cancer. The applicant for this medicinal product is Sandoz GmbH. Herwenda was authorized for medical use in the European Union in November 2023. Trastuzumab-strf (Hercessi) was approved for medical use in the United States in April 2024.
Sources: en.wikipedia.org
The earliest known compilation of medicinal substances was the Sushruta Samhita, an Indian Ayurvedic treatise attributed to Sushruta in the 6th century BC. However, the earliest text as preserved dates to the 3rd or 4th century AD. Many Sumerian (4th millennium BC – early 2nd millennium BC) cuneiform clay tablets record prescriptions for medicine. Ancient Egyptian pharmacological knowledge was recorded in various papyri such as the Ebers Papyrus of 1550 BC, and the Edwin Smith Papyrus of the 16th century BC.
== Habitat == Brown recluse spiders build asymmetrical (irregular) webs that frequently include a shelter consisting of disorderly threads. They frequently build their webs in woodpiles and sheds, closets, garages, plenum spaces, cellars, and other places that are dry and generally undisturbed. When dwelling in human residences they seem to favor cardboard, possibly because it mimics the rotting tree bark which they inhabit naturally. Human-recluse contact often occurs when such isolated spaces are disturbed and the spider feels threatened. Unlike most web weavers, they leave these lairs at night to hunt. Males move around more when hunting than the females, which tend to remain nearer to their webs.
==== Luminal ions ==== In addition to NAADP gating the channel, there is evidence that the luminal pH also affects TPC channel activity, either TPC1 [1] or TPC2 [2][3]. However, a clear consensus on the effect of pH has not been reached with some suggesting that acidic pH favours TPC1 or TPC2 opening, whereas others report that a more alkaline pH favours TPC2 opening. Furthermore, luminal Ca2+ also promotes TPC1 and TPC2 opening (in the latter case, luminal Ca2+ also sensitizes TPCs to NAADP (analogous to luminal Ca2+ regulation of IP3Rs and RyRs), but this demands wider study across isoforms and species. This is one way by which cross-talk can occur between acidic Ca2+ stores and the ER i.e. Ca2+ release from the ER can 'prime' acidic Ca2+ stores and promote further NAADP-dependent Ca2+ responses [4].
Epitope tags include ALFA-tag, V5-tag, Myc-tag, HA-tag, Spot-tag, T7-tag and NE-tag. These tags are particularly useful for western blotting, immunofluorescence and immunoprecipitation experiments, although they also find use in antibody purification. First described in 1984 by Munro and Pelham to detect and track proteins in COS cells, epitope tags were quickly adapted to track proteins in Xenopus oocytes; to detect and immunoaffinity purify proteins from yeast and E. coli; and to detect, pull down, and clone interaction partners of ligands in mammalian cells. At first, these tags were referred to as "peptide tag", "epitope insertion", "marker sequence", and "epitope addition", until "epitope tag" was coined and popularized. Fluorescence tags are used to give visual readout on a protein. Green fluorescent protein (GFP) and its variants are the most commonly used fluorescence tags. More advanced applications of GFP include using it as a folding reporter (fluorescent if folded, colorless if not). Protein tags may allow specific enzymatic modification (such as biotinylation by biotin ligase) or chemical modification (such as coupling to other proteins through SpyCatcher or reaction with FlAsH-EDT2 for fluorescence imaging). Often tags are combined, in order to connect proteins to multiple other components. However, with the addition of each tag comes the risk that the native function of the protein may be compromised by interactions with the tag. Therefore, after purification, tags are sometimes removed by specific proteolysis (e.g.
=== Block copolymer-mediated method === An economical, environmentally benign and fast synthesis methodology for gold nanoparticles using block copolymer has been developed by Sakai et al. In this synthesis methodology, block copolymer plays the dual role of a reducing agent as well as a stabilizing agent. The formation of gold nanoparticles comprises three main steps: reduction of gold salt ion by block copolymers in the solution and formation of gold clusters, adsorption of block copolymers on gold clusters and further reduction of gold salt ions on the surfaces of these gold clusters for the growth of gold particles in steps, and finally its stabilization by block copolymers. But this method usually has a limited-yield (nanoparticle concentration), which does not increase with the increase in the gold salt concentration. Ray et al. improved this synthesis method by enhancing the nanoparticle yield by manyfold at ambient temperature.
Sources: en.wikipedia.org
It binds and activates PPARδ, a nuclear receptor that influences gene expression related to fatty acid metabolism and energy balance. This mechanism has been studied mainly in animals and cell models, not established as a safe human therapy.
No. It is not an anabolic-androgenic steroid; it is a synthetic PPARδ agonist. Because it is banned in sport, it is sometimes grouped with doping agents even though its chemical class differs from steroids.
Human data are limited and development was discontinued, so major effects and long-term risks are not well characterized. Some early studies examined metabolic markers, but they do not provide a basis for unsupervised use.
Anti-doping laboratories typically use LC-MS/MS to detect GW501516 and its metabolites in urine. The method is sensitive and can identify the compound at low concentrations. Detection depends on sample timing, metabolism, and the specific assay.