Metabolite comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
Laboratory detection of cardarine typically involves sample preparation followed by chromatographic separation and mass spectrometric identification. Urine is the most common matrix for anti-doping tests, though blood and hair have also been explored. Methods can target the parent compound or its metabolites, depending on the expected window of detection. Reference standards are required for accurate quantification. Matrix effects and dilution can influence results, so laboratories use internal standards and validation protocols. The exact detection window varies with dose, route, and individual metabolism.
A common misconception is that cardarine has been proven safe for human use. In reality, human clinical data are limited, and long-term animal studies have raised concerns about cancer. Another misconception is that it is a supplement or vitamin-like compound. It is a synthetic research chemical with no approved medical indication. Scientific discussion often focuses on its mechanism and detection rather than therapeutic use. Regulatory and anti-doping literature treats it primarily as a prohibited substance.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Prohibited in sport | Listed by WADA as a PPARδ agonist. |
| Typical detection matrix | Urine | Most common sample for anti-doping analysis. |
| Common analytical method | LC-MS/MS | Liquid chromatography-tandem mass spectrometry. |
| Common synonyms | GW501516, GSK-516, endurobol | Names found in research and fitness contexts. |
| Typical detection window | Variable | Depends on dose, route, and individual metabolism. |
Human trials of GW501516 were small and short in duration. They examined lipid levels, glucose handling, and other metabolic markers, but the programs were halted after the animal cancer findings. No approved therapeutic product exists, and published human data are insufficient for establishing long-term safety. Reports of use for athletic performance come mainly from non-clinical settings and cannot be verified through controlled trials. Independent testing of products sold as cardarine has found inconsistent purity and labeling.
Laboratory studies indicate that GW501516 activates PPARδ, a nuclear receptor involved in fatty acid oxidation and energy metabolism. In rodent experiments, treated animals often showed increased endurance and reduced fat mass. These effects were observed under controlled conditions and do not establish safe or effective use in humans. The exact dose-response relationship in humans remains poorly characterized. Species differences in metabolism can affect how results translate across animals and people.
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.
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.
The PAH world hypothesis is a speculative hypothesis that proposes that polycyclic aromatic hydrocarbons (PAHs), known to be abundant in the universe, including in comets, and assumed to be abundant in the primordial soup of the early Earth, played a major role in the origin of life by mediating the synthesis of RNA molecules, leading into the RNA world. However, as yet, the hypothesis is untested.
=== Literature === Sea of Poppies, a fictional novel by Amitav Ghosh uses the opium poppy as a central theme throughout the narrative, with a main setting of the poppy fields of the Ganges River Plain.
== History == Lurbinectedin was approved for medical use in the United States in June 2020. Efficacy was demonstrated in the PM1183-B-005-14 trial (Study B-005; NCT02454972), a multi-center open-label, multi-cohort study enrolling 105 participants with metastatic small cell lung cancer who had disease progression on or after platinum-based chemotherapy. Participants received lurbinectedin 3.2 mg/m2 by intravenous infusion every 21 days until disease progression or unacceptable toxicity. The trial was conducted at 26 sites in the United States, Great Britain, Belgium, France, Italy, Spain and Czech Republic. The US Food and Drug Administration (FDA) granted the application for lurbinectedin priority review and orphan drug designations and granted the approval of Zepzelca to Pharma Mar S.A. The efficacy of lurbinectedin used in combination with atezolizumab or in combination with atezolizumab/hyaluronidase was evaluated in IMforte (NCT05091567), a randomized, multi-center, open-label trial in participants receiving first-line treatment for extensive-stage small cell lung cancer. In IMforte, 483 participants with extensive-stage small cell lung cancer whose disease had not progressed after completion of four cycles of atezolizumab, carboplatin, and etoposide (induction treatment) were randomized (1:1) to receive either lurbinectedin in combination with atezolizumab administered intravenously or atezolizumab intravenously alone until disease progression or unacceptable toxicity.
== Mechanism of action == Thiamazole inhibits the enzyme thyroperoxidase, which normally acts in thyroid hormone synthesis by oxidizing the anion iodide (I−) to iodine (I2), hypoiodous acid (HOI), and enzyme linked hypoiodate (EOI), facilitating iodine's addition to tyrosine residues on the hormone precursor thyroglobulin, a necessary step in the synthesis of triiodothyronine (T3) and thyroxine (T4). It does not inhibit the action of the sodium-dependent iodide transporter located on follicular cells' basolateral membranes. Inhibition of this step requires competitive inhibitors such as perchlorate and thiocyanate. A study has shown that it modulates secretion of CXCL10.
Innovations in statistical analysis by Ronald Fisher, Frank Yates and others at Rothamsted Experimental Station facilitated rational experimental design and data analysis in botanical research. The discovery and identification of the auxin plant hormones by Kenneth V. Thimann in 1948 enabled the regulation of plant growth by externally applied chemicals. Frederick Campion Steward pioneered techniques of micropropagation and plant tissue culture controlled by plant hormones. The synthetic auxin 2,4-dichlorophenoxyacetic acid or 2,4-D was one of the first commercial synthetic herbicides.
Sources: en.wikipedia.org
== Professional ventures and affiliations == Early in his career, Ariely co-founded the behavioral economics consulting firm BEworks, which was acquired by Kyu in 2017. In 2012, aspiring to develop a time management app that helps people "use time better" and avoid procrastination, Ariely co-founded Timeful with Yoav Shoham and Jacob Bank. The app was acquired by Google in 2015. In 2013, Ariely and Kristen Berman co-founded Irrational Labs, a consulting firm aimed at applying behavioral economics to consumer behavior and decision-making. In 2014, Ariely co-founded the kitchen appliance company Genie with Ayelet Carasso-Stenberg and Doron Marco. Genie manufactures a food "replicator" that cooks freeze-dried meals in cartridges. In 2015, Ariely invested in Qapital, a personal finance app, and was appointed as its chief behavioral economist. He was later named chair of the board. In 2015, Ariely gave a talk at Google about dating and relationships, discussing what women want from men, including how women's attraction to men varies depending where they are in their menstrual cycle. This was one of many talks Ariely collaborated with Google on over several years, including, for example, a talk about how people rationalize cheating. In 2016, he took on the position of chief behavioral officer at Lemonade, an insurance company that integrates aspects of behavioral economics into its insurance model. Ariely's entrepreneurial ventures also include founding Shapa in 2017, a company focused on health monitoring and behavior change.
Fasting blood sugar (glucose) level of: 110 to 125 mg/dL (6.1 mmol/L to 6.9 mmol/L) – WHO criteria 100 to 125 mg/dL (5.6 mmol/L to 6.9 mmol/L) – ADA criteria Glucose tolerance test: blood sugar level of 140 to 199 mg/dL (7.8 to 11.0 mM) 2 hours after ingesting a standardized 75 gram glucose solution (WHO and ADA criteria) Glycated hemoglobin (HbA1c) between 5.7 and 6.4 percent, i.e., 38.9 and 46.4 mmol/mol Levels above these limits would justify a diagnosis for diabetes.
== S == safe sex – safer sex – salmonella – salvage therapy – SAMHSA – sarcoma – seborrheic dermatitis – secondary prophylaxis – sepsis – seroconversion – serologic test – seroprevalence – serosorting – serostatus – serum – serum glutamic oxaloacetic transaminase (SGOT) – serum glutamic pyruvate transaminase (SGPT) – sexually transmitted disease (STD) – shingles – SHIV – side effects – simian immunodeficiency virus (SIV) – sinusitis – social integration SIT – SIV – Special Projects of National Significance (SPNS) – spinal tap – spleen – splenomegaly – sputum analysis – standard of care – staphylococcus – STD – stem cells (FDCs) – steroid – Stevens–Johnson syndrome – STI – stomatitis – strain – stratification – structured intermittent therapy (SIT) – structured treatment interruption (STI) – study endpoint – subarachnoid space – subclinical infection – subcutaneous (SQ) – Substance Abuse and Mental Health Services Administration (SAMHSA) – subunit HIV vaccine – sulfa drug – sulfonamides – superantigen – suppressor T cell – surrogate marker – surveillance – susceptible – symptoms – syncytium – syndrome – synergy – synergistic – synthesis – syphilis – systemic
=== Flammability === In the 1960s there was a lot of interest in fluorocarbons as anesthetics. The research did not produce any anesthetics, but the research included tests on the issue of flammability, and showed that the tested fluorocarbons were not flammable in air in any proportion, though most of the tests were in pure oxygen or pure nitrous oxide (gases of importance in anesthesiology).
=== Rivalries === A strong athletic rivalry exists between the University of Arizona and Arizona State University in Tempe, Arizona. The University of Arizona leads the all-time record against Arizona State University in men's basketball (149–83), as well as in football (49–42–1). The football rivalry game between the schools is known as "The Duel in the Desert". The trophy awarded after each game is the Territorial Cup. Rivalries have also been created with other Pac-12 teams, especially the University of California, Los Angeles which has proved to be a worthy softball rival and was Arizona's main basketball rival for most of 1990s.
Sources: en.wikipedia.org
Yes, WADA prohibits cardarine as a PPARδ agonist. It appears on the prohibited list and can be detected in urine or blood. Athletes using it risk sanctions.
Detection usually uses liquid chromatography-tandem mass spectrometry after sample cleanup. Laboratories look for the parent compound or metabolites. The method requires validated reference standards and controls.
Legality varies by country. In many places it is an unapproved drug and cannot be legally sold for human consumption. Purchasing from online vendors carries legal and quality risks.
Legal status varies by country, but cardarine is not approved as a medicine in major jurisdictions. It is often sold as a research chemical, a category that may not be lawful for human use. Buyers should check local laws and product labels carefully.