WADA raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-05-25. Anything still debated is marked as such rather than presented as settled.
Legal status varies by country. In some places, cardarine is controlled under medicines or psychoactive substances laws; in others, it may be sold with minimal oversight as a research chemical. Customs agencies have intercepted shipments, and several national health agencies have issued warnings about products marketed for bodybuilding or performance enhancement. The lack of a standardized pharmaceutical supply means identity, purity, and contamination levels can differ widely between samples. These factors make cardarine a regulatory and public health concern rather than a conventional prescription drug.
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.
Published studies have examined GW501516 in animal models of obesity, insulin resistance, and exercise endurance. Early human trials reportedly ended, and development was discontinued after preclinical findings raised concerns about cancer in some rodent studies. Regulatory agencies have not approved cardarine for any medical use. Its availability through non-pharmaceutical channels raises questions about identity, purity, and legal status that are separate from its laboratory pharmacology. Those questions are often addressed through analytical testing rather than assumptions about product labels.
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.
| Property | Value | Notes |
|---|---|---|
| IUPAC name | {4-[({4-methyl-2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-5-yl}methyl)sulfanyl]phenoxy}acetic acid | Systematic name for GW501516 |
| CAS Registry Number | 317318-70-0 | Unique identifier for the parent compound |
| Molecular formula | C21H18F3NO3S2 | Includes carbon, hydrogen, fluorine, nitrogen, oxygen, and sulfur |
| Molecular weight | 453.5 g/mol | Approximate value for the neutral form |
| Appearance | White to off-white powder | Typical description for purified laboratory material |
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.
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.
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.
Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.
Two examples of this are the US Navy's Grumman E-2 Hawkeye and the US Air Force's Boeing E-3 Sentry. Both were used in command and control area of operations. These systems provided essential communications links between air, ground, and naval forces. It is one of several reasons coalition forces dominated the air war. American-made color photocopiers were used to produce some of Iraq's battle plans. Some of the copiers contained concealed high-tech transmitters that revealed their positions to American electronic warfare aircraft, leading to more precise bombings.
=== GPR139 receptor === Big dynorphin is one of the activators of the GPR139, a G protein-coupled receptor (GPCR), recently deorphanized as a dynorphin receptor. In a wide neuropeptide library screen it exhibited one of the highest efficacies among prodynorphin-derived peptides. At low concentrations, dynorphins predominantly activate canonical opioid receptors (KOR, MOR, DOR), while at higher concentrations, they additionally recruit GPR139. This receptor couples to Gq/11 G protein-mediated signaling, which is mechanistically opposite to the Gi/o inhibitory signaling of classical opioid receptors. This permits GPR139 to function as a molecular homeostatic brake: when dynorphin reaches high concentrations during intense stress or pain, simultaneous GPR139 activation counteracts excessive opioid receptor signaling through excitatory signaling pathways, preventing pathological over-inhibition of neuronal activity.
In early August, the division was transferred to East Prussia from Army Group South Ukraine. Over the next months, Großdeutschland was involved in heavy fighting in both East Prussia – including a counter-attack on Wilkowischken – and the Baltic States, suffering high casualties in both men and materiel. The division was nearly destroyed during the battles in the Memel bridgehead.
== History == Ketobemidone was first synthesized in 1942 by Eisleb and colleagues, at the laboratory of I.G. Farbenindustrie at Hoechst during the Second World War. The first study of it in humans was published in 1946, and it was introduced in clinical medicine shortly after. It was not in clinical use in the United States when the Controlled Substances Act 1970 was promulgated and was assigned to Schedule I with an ACSCN of 9628. As of 2013, no annual manufacturing quota was assigned by the DEA. Pfizer manufactures ketobemidone under the tradenames Ketogan and Ketorax. It is available as tablets, suppositories, and injection fluid. A sustained release formulation, sold as Ketodur, exists in some countries and contains 10 or 25 mg ketobemidone.
Lectin affinity chromatography is a form of affinity chromatography where lectins are used to separate components within the sample. Lectins, such as concanavalin A are proteins which can bind specific alpha-D-mannose and alpha-D-glucose carbohydrate molecules. Some common carbohydrate molecules that is used in lectin affinity chromatography are Con A-Sepharose and WGA-agarose. Another example of a lectin is wheat germ agglutinin which binds D-N-acetyl-glucosamine. The most common application is to separate glycoproteins from non-glycosylated proteins, or one glycoform from another glycoform. Although there are various ways to perform lectin affinity chromatography, the goal is extract a sugar ligand of the desired protein.
Sources: en.wikipedia.org
Its half-life was initially determined to be about 3 million years (later revised to 2.144 million years), confirming the predictions of Nishina and Kimura of a very long half-life. Early research into the element was somewhat limited because most of the nuclear physicists and chemists in the United States at the time were focused on the massive effort to research the properties of plutonium as part of the Manhattan Project. Research into the element did continue as a minor part of the project and the first bulk sample of neptunium (as neptunium dioxide) was isolated in 1944. Much of the research into the properties of neptunium since then has been focused on understanding how to confine it as a portion of nuclear waste. Because it has isotopes with very long half-lives, it is of particular concern in the context of designing confinement facilities that can last for thousands of years. It has found some limited uses as a radioactive tracer and a precursor for various nuclear reactions to produce useful plutonium isotopes. However, most of the neptunium that is produced as a reaction byproduct in nuclear power stations is considered to be a waste product.
The thiazolidinediones , abbreviated as TZD, also known as glitazones after the prototypical drug ciglitazone, are a class of heterocyclic compounds consisting of a five-membered C3NS ring. The term usually refers to a family of drugs used in the treatment of diabetes mellitus type 2 that were introduced in the late 1990s. As of 2024, there are two FDA-approved drugs in this class, pioglitazone and rosiglitazone.
A nonsynonymous mutation that occurs at the genomic or transcriptional levels is one that results in an alteration to the amino acid sequence in the protein product. A protein's primary structure refers to its amino acid sequence. A substitution of one amino acid for another can impair protein function and tertiary structure, however its effects may be minimal or tolerated depending on how closely the properties of the amino acids involved in the swap correlate. The premature insertion of a stop codon, a nonsense mutation, can alter the primary structure of a protein. In this case, a truncated protein is produced. Protein function and folding is dependent on the position in which the stop codon was inserted and the amount and composition of the sequence lost. Conversely, silent mutations are mutations in which the amino acid sequence is not altered. Silent mutations lead to a change of one of the letters in the triplet code that represents a codon, but despite the single base change, the amino acid that is coded for remains unchanged or similar in biochemical properties. This is permitted by the degeneracy of the genetic code. Historically, silent mutations were thought to be of little to no significance. However, recent research suggests that such alterations to the triplet code do affect protein translation efficiency and protein folding and function. Furthermore, a change in primary structure is critical because the fully folded tertiary structure of a protein is dependent upon the primary structure.
A proteome is the entire set of proteins that is, or can be, expressed by a genome, cell, tissue, or organism at a certain time. It is the set of expressed proteins in a given type of cell or organism, at a given time, under defined conditions. Proteomics is the study of the proteome.
Sources: en.wikipedia.org
No. Major drug regulators have not approved GW501516 for treating any medical condition. Products sold as cardarine are typically unapproved research chemicals or supplements, so their contents and safety are not assured.
It is prohibited by the World Anti-Doping Agency as a hormone and metabolic modulator. Athletes who test positive for GW501516 can face sanctions, including suspensions and loss of results.
Cardarine is a common or trade-style name, while GW501516 is the research code for the same chemical entity. Some sources also use Endurobol or GSK-516. The names refer to the same compound, not distinct drugs.
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.