If you have been reading about Anti-doping and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-02-21. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Early clinical research explored GW501516 for lipid disorders, obesity, and diabetes. Some short-term human studies reported changes in HDL cholesterol, LDL cholesterol, and triglycerides. The development program was discontinued after rodent studies showed dose-dependent tumor formation in multiple tissues, including liver, bladder, stomach, and skin. These findings raised concerns about long-term cancer risk in humans. Because human exposure data are limited, the clinical significance of the rodent tumors remains uncertain.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Primary target | PPARδ | Nuclear receptor; not androgen receptor |
| Studied indications | Dyslipidemia; obesity; diabetes | Early clinical research; development discontinued |
| Rodent toxicity | Tumor formation in multiple tissues | Dose-dependent findings in some studies |
| Human approval | None | No approved therapeutic use |
| Typical analytical method | LC-MS/MS | Used for identity and quantification |
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.
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 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.
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.
At the molecular level, GW501516 binds and activates PPARδ, a nuclear receptor that regulates transcription. Activation shifts expression of genes involved in fatty acid oxidation, energy expenditure, and lipid transport in skeletal muscle and liver. Animal studies report increased endurance and altered lipid profiles after exposure. Human data are limited to small trials and do not establish long-term safety or efficacy. PPARδ also has roles in cell proliferation, so the relationship between activation and cancer risk remains an open question.
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 a synthetic compound also known as GW501516, GW-501516, and sometimes endurobol. It was developed as a selective agonist of peroxisome proliferator-activated receptor delta, a nuclear receptor involved in fatty acid oxidation and energy metabolism. The compound was studied in preclinical models for metabolic and cardiovascular conditions, but it did not become a marketed human medicine. In regulatory and anti-doping contexts, it is treated as a prohibited substance rather than a licensed medicine.
The pharmacological interest in cardarine centers on PPARδ activation and its downstream effects on lipid handling and mitochondrial function. In animal studies, PPARδ agonists have been associated with changes in exercise endurance and fatty acid utilization, though results vary by model and protocol. Human data remain sparse, and the absence of large controlled trials limits conclusions about efficacy. Researchers often describe the compound as a tool for probing PPARδ biology rather than a proven therapeutic agent.
Safety discussions about cardarine frequently cite rodent carcinogenicity findings reported in the 2000s. In those studies, treated animals developed tumors at multiple sites, leading sponsors to discontinue clinical development. The relevance of these findings to humans has not been resolved, but they are a major reason the compound is not approved. Current literature emphasizes uncertainty about long-term effects and the risks of unregulated use. Regulators and health agencies have not established a safe human exposure level.
Non-prescription topical products that have health claims for reducing facial acne, combating skin dark spots and reducing wrinkles and lines associated with aging often contain retinyl palmitate. The hypothesis is that this is absorbed and de-esterified to free retinol, then converted to retinaldehyde and further metabolized to all-trans-retinoic acid, whence it will have the same effects as prescription products with fewer side effects. There is some ex vivo evidence with human skin that esterified retinol is absorbed and then converted to retinol. In addition to esterified retinol, some of these products contain hydroxypinacolone retinoate, identified as esterified 9-cis-retinoic acid.
A major function of FPR2 is to bind certain specialized pro-resolving mediators (SPMs)—including lipoxin (Lx)A4, AT-LxA4 (arachidonic acid metabolites), and resolvin D1 (RvD1), RvD2, and AT-RvD1 (derived from docosahexaenoic acid)—and to mediate their inflammation-resolving effects. In addition, FPR2 also responds to a wide range of peptides and proteins that may promote inflammation or regulate unrelated processes. The physiological role of FPR3 remains unclear.
=== Inflammatory arthropathies === Rheumatoid arthritis Spondyloarthropathies Ankylosing spondylitis Reactive arthritis (reactive arthropathy) Psoriatic arthropathy Enteropathic arthropathy Juvenile idiopathic arthritis (JIA) Crystal arthropathies: gout, pseudogout Septic arthritis Raynaud's Disease
=== Organic carbon === The removal of organic carbon from water is one of the differentiators between deionized water and ultrapure water. Sources include bacteria, leaching from plastic piping, and dissolved atmospheric sources. Organic carbon can be removed using filtration by activated carbon and oxidation of organic carbon to carbon dioxide/bicarbonate.
Sources: en.wikipedia.org
=== American Hospital Association (AHA) === The American Hospital Association has expressed concern that FDA's proposal to classify LDTs as medical devices exceeds the agency's appropriate regulatory scope, urging the FDA to continue to apply its enforcement discretion to hospital and health system LDTs and defer regulation of these tests mainly to CMS's strict CLIA oversight, the CAP accreditation and state law. The organization has called on Congress to either exclude hospitals and health systems from this device classification framework or to modernize LDT oversight in a way that promotes innovation while maintaining test accessibility, safety, and effectiveness.
== Activities unrelated to the central dogma == The central dogma of molecular biology states that, once sequential information has passed from nucleic acid to protein, it cannot flow back from protein to nucleic acid. Some people believe that the following activities conflict with the central dogma.
The authors also performed regression analyses to demonstrate the relationship between tooth height and skull length, and found that varanids like the crocodile monitor had substantially greater ratios of tooth height to skull length than those of Tyrannosaurus, indicating that the teeth of theropods were not too big to be covered by extraoral tissues when the mouth was closed.
Sources: en.wikipedia.org
Pauses a rule issued under the Biden administration to cancel student loans if schools engaged in deceptive recruiting; Caps unsubsidized student loans for graduate students at $20,500 per year and $100,000 lifetime; Caps student loans for students seeking professional degrees, such as medical school or law school, at $50,000 per year and $200,000 lifetime, and eliminates graduate PLUS loans; Establishes a lifetime student loan borrowing limit of $257,000; Restructures income-based repayment programs; and Expands Pell Grants to cover workforce-training programs.
==== US Federal Trade Commission ==== On 27 February 2019, the United States Federal Trade Commission (FTC) reached a consent decree with ByteDance, fining it US$5.7 million for collecting information from minors under the age of 13 in violation of the Children's Online Privacy Protection Act (COPPA). ByteDance responded by adding a kids-only mode to TikTok which blocks the upload of videos, the building of user profiles, direct messaging, and commenting on others' videos, while still allowing the viewing and recording of content. In May 2020, an advocacy group filed a complaint with the FTC saying that TikTok had violated the terms of the February 2019 consent decree with the FTC, which sparked subsequent congressional calls for a renewed FTC investigation. In March 2022, following a class action lawsuit for violations of COPPA, TikTok settled for US$1.1 million. In March 2024, it was reported that the FTC continues to investigate TikTok. In August 2024, the FTC and US Department of Justice filed a joint lawsuit alleging violations of the 2019 consent decree. In August 2026, TikTok and ByteDance agreed to pay $400 million to settle the lawsuit.
=== 2010s === In 2010, Grace received approval from the U.S. Bankruptcy Court for the merger with Synthetec, which is a company that had developed and manufactured amino acid and peptide products as well as proprietary custom chiral intermediates primarily for the pharmaceutical industry. In 2014, the Grace bankruptcy process terminated. However, some legal procedures continued into the next decade. In February 2016, Grace completed the corporate spin-off of GCP Applied Technologies, which was also as a public trading corporation on the NYSE. Grace shareholders receive GCP stock on 1:1 ratio. GCP Applied Technologies consisted of the concrete admixture and related products company Grace Construction Products (GCP) and Darex, a packaging technologies business unit. In July 2016, Grace acquired the global polyolefin catalysts business unit from BASF.
Sources: en.wikipedia.org
It targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not act primarily on androgen receptors. This distinction separates it from SARMs.
Rodent studies found dose-dependent tumors in several organs. The sponsor discontinued the program over cancer concerns. Human risk from long-term use remains unknown.
Controlled human endurance trials are lacking. Animal studies show increased exercise capacity under some conditions. Anecdotal reports are not equivalent to clinical evidence.
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.