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Background And Regulatory History — Field Notes

By Editorial Desk · published 2026-02-12 · last reviewed 2026-02-26 · Blog

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 2026-02-26. Where a claim depends on a specific study, the study is described rather than over-claimed.

Background and Regulatory History

Regulatory bodies treat GW501516 as a prohibited substance in competitive sport. The World Anti-Doping Agency added it to the prohibited list, and it falls under classes covering metabolic modulators and hormone-related agents. It is not approved by drug regulators for human use, and it is not a lawful dietary supplement. Products sold under the cardarine name may contain unlisted ingredients or different compounds. Because no approved product exists, quality and identity are not guaranteed by pharmaceutical manufacturing standards.

Cardarine is a common name for the investigational chemical GW501516, also written GW-1516. It was developed as a peroxisome proliferator-activated receptor delta agonist for metabolic conditions such as dyslipidemia. Early research focused on lipid handling and energy use in skeletal muscle and other tissues. The compound was never approved as a medicine. In public discussion, it is often grouped with performance-enhancing substances, although its receptor target differs from that of anabolic steroids or selective androgen receptor modulators. Regulatory and health authorities have issued warnings about its use.

Regulation and Detection

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.

Cardarine is frequently described as a fat-burning or endurance-enhancing supplement, but these claims exceed the available evidence. The compound is not a hormone, steroid, or selective androgen receptor modulator. Research articles discuss it as a tool compound for studying PPARδ biology, while anti-doping literature focuses on its abuse and detection. Quality of unapproved products is uncertain, and independent analyses have found impurities or incorrect labeling. Open questions include whether human cancer risk resembles that seen in rodents and how often non-athletes use the substance.

Cardarine at a glance

PropertyValueNotes
Common nameCardarineCommon internet and media name.
Research codeGW501516Also written GW-1516.
Drug classPPARδ agonistNot a selective androgen receptor modulator.
Development statusDiscontinuedClinical development halted after rodent cancer findings.
Regulatory statusProhibited in sportListed by WADA; not approved as medicine.

Regulation and Analytical Detection

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.

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Cardarine as Investigational PPARδ Agonist

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.

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.

Identity and Pharmacological Classification

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.

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.

Notes from published material

== History == Colonies of B. cereus were originally isolated by Percy F. Frankland from a gelatine plate left exposed to the air in a cow shed in 1887. In the 2010s, examination of warning letters issued by the US Food and Drug Administration issued to pharmaceutical manufacturing facilities addressing facility microbial contamination revealed that the most common contaminant was B. cereus. Several new enzymes have been discovered in B. cereus, such as AlkC and AlkD, both of which are involved in DNA repair.

4-Fluoroisobutyrylfentanyl (also known as 4-FIBF and p-FIBF) is an opioid analgesic that is an analog of butyrfentanyl and structural isomer of 4-Fluorobutyrfentanyl and has been sold online as a designer drug. It is closely related to 4-fluorofentanyl, which has an EC50 value of 4.2 nM for the human μ-opioid receptor. 4-fluoroisobutyrylfentanyl is a highly selective μ-opioid receptor agonist whose analgesic potency is almost ten times of that reported for morphine.

== Adverse effects == The most common side effects include nausea (feeling sick), vomiting, constipation, loss of appetite, alopecia (hair loss), headache, fatigue (tiredness), convulsions (fits), rash, neutropenia or lymphopenia (low white-blood-cell counts), and thrombocytopenia (low blood platelet counts). People receiving the solution for infusion may also have injection-site reactions, such as pain, irritation, itching, warmth, swelling and redness, as well as bruising.

Sulfuric acid is a very important commodity chemical, and a nation's sulfuric acid production was as recently as 2002 believed to be a good indicator of its industrial strength. World production in the year 2004 was about 180 million tonnes, with the following geographic distribution: Asia 35%, North America (including Mexico) 24%, Africa 11%, Western Europe 10%, Eastern Europe and Russia 10%, Australia and Oceania 7%, South America 7%. World production in 2022 was estimated at 260 million tonnes. As of the late 20th century, most of the produced amount (≈60%) was consumed for fertilizers, particularly Superphosphates, ammonium phosphate and Ammonium sulfates. About 20% is used in chemical industry for production of detergents, synthetic resins, dyestuffs, pharmaceuticals, petroleum catalysts, insecticides and antifreeze, as well as in various processes such as oil well acidicizing, aluminium reduction, paper sizing, and water treatment. About 6% of uses are related to pigments and include paints, enamels, printing inks, coated fabrics and paper, while the rest is dispersed into a multitude of applications such as production of explosives, cellophane, acetate and viscose textiles, lubricants, non-ferrous metals, and batteries. Sulfuric acid is used as a consumable for the extraction of copper from oxides in leaching piles. Chile, the world's leading producer of copper, required sulfuric acid in about 20% of its copper production as of 2026.

Sources: en.wikipedia.org

Further detail

== 2016 suspension from coaching == On 12 January 2016, McVeigh was named as one of 34 past and present Essendon players found guilty over their use of illegal supplements during the 2012 AFL season. As a result, McVeigh was suspended from involvement in football for twenty-four months, which (due to back-dating and time served in provisional suspensions) saw him suspended until November 2016. The terms of the suspension meant that McVeigh was unable to continue his assistant coaching role at Greater Western Sydney during 2016.

== History == The FDA's approval of sildenafil in 1998 was a ground-breaking commercial event for the treatment of ED, with sales exceeding US$1 billion. Subsequently, the FDA approved both vardenafil and tadalafil in 2003. It initially was developed by the biotechnology company ICOS, and then again developed and marketed worldwide by Lilly ICOS, LLC, the joint venture of ICOS Corporation and Eli Lilly and Company. Tadalafil was approved in 2009 in the United States for the treatment of pulmonary arterial hypertension and is under regulatory review in other regions for this condition. In late November 2008, Eli Lilly sold the exclusive rights to commercialize tadalafil for pulmonary arterial hypertension in the United States to United Therapeutics for an upfront payment of $150 million. Tadalafil was discovered by Glaxo Wellcome (now GlaxoSmithKline) under a partnership between Glaxo and ICOS to develop new drugs that began in August 1991. In 1993, the Bothell, Washington, biotechnology company ICOS Corporation began studying compound IC351, a phosphodiesterase type 5 (PDE5) enzyme inhibitor. In 1994, Pfizer scientists discovered that sildenafil, which also inhibits the PDE5 enzyme, caused penile erection in males participating in a clinical study of a heart medicine. Although ICOS scientists were not testing compound IC351 for treating ED, they recognized its potential usefulness for treating that disorder. Soon, in 1994, ICOS received a patent for compound IC351 (structurally unlike sildenafil and vardenafil), and Phase 1 clinical trials began in 1995.

gwrthddatgysylltiadaeth (antidisestablishmentarianism) microgyfrifiaduron (microcomputers) gwrthgyfansoddiaethwyr (anticonstitutionalists) lled-ddargludyddion (semiconductors) tra-arglwyddiaethasant (they tyrannised) cyfrwngddarostynedigaeth (intercession) (-au can be added to form the plural, and the word can be further lengthened slightly by initial mutation: fy nghyfrwngddarostynedigaethau, "my intercessions")

However, the Cherokee Nation has argued the United Keetoowah Band's argument is legally incorrect and only the Cherokee Nation has jurisdiction to the 14 county reservation and that the United Keetoowah Band only has jurisdiction over their 76 acres of trust land.

=== Cancer === In 2015, the International Agency for Research on Cancer (IARC) classified unprocessed red meat as "probably carcinogenic to humans (Group 2A)". To make this classification, the IARC Working Group assessed over 800 epidemiological studies in addition to other types of studies such as animal bioassays. When assessing whether substances are carcinogenic to humans, it is rare for data from randomized trials to be available. The Working Group found "limited" epidemiological evidence linking unprocessed red meat to colorectal, pancreatic, and prostate cancer. Additionally, it found "strong mechanistic evidence" that unprocessed red meat is carcinogenic. Mechanistic evidence is evidence of plausible biological pathways in which a substance could cause cancer. For instance, studies had found that participants who had recently eaten red meat had higher levels of carcinogenic N-nitroso compounds in their guts and feces. For processed red meat, evidence of harm is stronger. The IARC classified processed meat as carcinogenic to humans (Group 1), based on "sufficient evidence in humans that the consumption of processed meat causes colorectal cancer." The American Institute for Cancer Research, Cancer Research UK and World Cancer Research Fund International have supported these conclusions. More recent meta-analyses have further supported the finding that high consumption of red meat is associated with increased risk of gastrointestinal cancer.

Sources: en.wikipedia.org

Frequently asked questions

Is cardarine a selective androgen receptor modulator?

No. Cardarine is a PPARδ agonist, while selective androgen receptor modulators act on androgen receptors. The two classes differ in receptor target and downstream effects.

Why did clinical development stop?

Preclinical rodent studies reported cancers, including liver and bladder tumors, at tested doses. The human relevance of those findings is uncertain, but development was discontinued. No approved human product resulted.

Is cardarine approved for medical use?

No. It remains an investigational compound without approved therapeutic labeling. Sports regulators prohibit its use, and health agencies have warned against consuming it.

Is cardarine legal?

Legal status varies by country. It is not approved as a medicine, and it is prohibited in sport. Some jurisdictions restrict import, sale, or possession.

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