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.
Last reviewed on 2025-11-25. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Detection of GW501516 in biological samples generally relies on liquid chromatography coupled with tandem mass spectrometry. Urine is a common matrix in anti-doping analysis, while blood or plasma may be used in research settings. Sample preparation can involve enzymatic hydrolysis, protein precipitation, or solid-phase extraction before instrumental analysis. Because the compound undergoes metabolism, assays may target the parent molecule, one or more metabolites, or both. Detection windows are not fixed; they depend on factors such as dose, route, individual metabolism, and assay sensitivity. Reference standards are required for accurate identification and quantification.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Visual description for typical solid reference material. |
| Solubility | Poorly soluble in water; soluble in DMSO | Solubility depends on solvent, purity, and form. |
| Storage | Cool, dry, protected from light | Long-term storage often uses low temperature and desiccant. |
| Common analytical method | LC-MS/MS | Used for detection and quantification in biological matrices. |
| Common synonyms | GW-501516; GW501516; endurobol | Naming varies among literature, vendors, and databases. |
Cardarine is a common name for GW501516, a synthetic compound first described in the 1990s as a selective agonist of the peroxisome proliferator-activated receptor delta. It was studied in preclinical models for metabolic and cardiovascular conditions, but it has not been approved as a medicine in the United States, Europe, or other major jurisdictions. Retail products labeled as cardarine are generally research chemicals or supplements, not pharmaceutical formulations. Because human safety and efficacy data remain limited, regulatory agencies treat it as an unapproved substance rather than a therapeutic product.
Sporting authorities added GW501516 to prohibited lists after it appeared in athlete samples and online markets. The World Anti-Doping Agency classifies it as a hormone and metabolic modulator, and its use can lead to an anti-doping rule violation. Some early laboratory work suggested effects on fatty acid oxidation and endurance-related metabolism in animals, but those findings do not establish safe or effective use in people. Reports of adverse events in humans are scarce and often anecdotal, which complicates risk assessment.
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.
GW501516 acts as a ligand for PPAR delta, a nuclear receptor that regulates transcription of genes involved in fatty acid oxidation and energy use. Activation of this receptor in skeletal muscle shifts metabolism toward fat burning in animal models. The compound does not burn fat directly; it changes gene expression over hours to days. Researchers study it to understand metabolic flexibility and exercise adaptation. Effects observed in rodents are not automatically expected in humans.
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.
== Role == Central nervous system fatigue is a key component in preventing peripheral muscle injury. The brain has numerous receptors, such as osmoreceptors, to track dehydration, nutrition, and body temperature. With that information as well as peripheral muscle fatigue information, the brain can reduce the quantity of motor commands sent from the central nervous system. This is crucial in order to protect the homeostasis of the body and to keep it in a proper physiological state capable of full recovery. The reduction of motor commands sent from the brain increases the amount of perceived effort an individual experiences. By forcing the body through a higher perceived intensity, the individual becomes more likely to cease exercise by means of exhaustion. Perceived effort is greatly influenced by the intensity of corollary discharge from the motor cortex that affects the primary somatosensory cortex. Endurance athletes learn to listen to their body. Protecting organs from potentially dangerous core temperatures and nutritional lows is an important brain function. Central nervous system fatigue alerts the athlete when physiological conditions are not optimal so either rest or refueling can occur. It is important to avoid hyperthermia and dehydration, as they are detrimental to athletic performance and can be fatal.
== Society and culture == Sweden's public health agency suggested that ephenidine be classified as a hazardous substance on 1 June, 2015. Due to that suggestion, ephenidine became a scheduled substance, in Sweden, as of 18 August, 2015. In 2016, Canada added MT-45 and "its salts, derivatives, isomers and analogues" to the Schedule I controlled substance list, and explicitly included ephenidine. Possession without legal authority can result in maximum 7 years imprisonment.
Valve has developed at least three game engines that have been used in its games. GoldSrc is based on a modified Quake engine by id Software, and used for the basis of Half-Life. Source was internally built from scratch as a replacement for GoldSrc, and was used for most of Valve's games in the early 2000s, including Half-Life 2, Team Fortress 2, and the Portal series. Source 2 is a refinement of the Source engine initially released in 2015, and has been used for Dota 2, CounterStrike 2, The Lab, and Half-Life: Alyx.
Sources: en.wikipedia.org
Although sodium-dependent transporters for vitamin C exists, it is present mainly in specialized cells whereas the glucose transporters, most notably GLUT1, transport DHA in most cells, where recycling back to ascorbic acid generates the necessary enzyme cofactor and intracellular antioxidant, (see Transport to mitochondria). The structure shown here for DHA is the commonly shown textbook structure. This 1,2,3-tricarbonyl is too electrophilic to survive more than a few milliseconds in aqueous solution, however. The actual structure shown by spectroscopic studies is the result of rapid hemiketal formation between the 6-OH and the 3-carbonyl groups. Hydration of the 2-carbonyl is also observed. The lifetime of the stabilized species is commonly said to be about 6 minutes under biological conditions. Destruction results from irreversible hydrolysis of the lactone bond, with additional degradation reactions following. Crystallization of solutions of DHA gives a pentacyclic dimer structure of indefinite stability. Recycling of vitamin C via active transport of DHA into cells, followed by reduction and reuse, mitigates the inability of humans to synthesize it from glucose.
Genetics (from Ancient Greek γενετικός genetikos, "genite" and that from γένεσις genesis, “origin”), a discipline of biology, is the science of heredity and variation in living organisms. Articles (arranged alphabetically) related to genetics include:
End of discussion." Sanders supports establishing worker-owned cooperatives and introduced legislation numerous times from the 1990s to the 2020s that would aid workers who want to "form their own businesses or to set up worker-owned cooperatives." As early as 1976, Sanders proposed workplace democracy, saying, "I believe that, in the long run, major industries in this state and nation should be publicly owned and controlled by the workers themselves." Likewise, he supports empowering and expanding labor unions to advance union democracy. In 1987, Sanders defined democracy as public ownership and workers' self-management in the workplace, saying: "Democracy means public ownership of the major means of production, it means decentralization, it means involving people in their work. Rather than having bosses and workers it means having democratic control over the factories and shops to as great a degree as you can." In his 2020 run for president, he proposed that 20% of stocks in corporations with over $100 million in annual revenue be owned by the corporation's workers and that 45% of the board of directors of corporations with over $100 million in annual revenue be elected by the workers of that corporation.
Sources: en.wikipedia.org
Cardarine targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not bind the androgen receptor in the way SARMs do.
Most methods use liquid chromatography with tandem mass spectrometry. Urine is common in anti-doping testing, and blood or plasma may be used in research.
Typical guidance is cool, dry, dark storage, often at low temperature and with desiccant. Stability data are limited, so storage conditions should be verified for each batch or supplier.
Cardarine is commonly known as GW501516 or GW-1516. These names refer to the same synthetic compound. It is not a brand-name approved medicine.