Prohibited substance raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-04-19 and is reviewed periodically as new material appears.
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.
GW501516 acts on PPARδ, a nuclear receptor that helps regulate fatty acid oxidation and energy homeostasis. In animal studies, activation of this receptor was associated with increased endurance and changes in lipid metabolism. Human trials examined effects on blood lipids and other metabolic markers, but the compound did not advance to approval. Rodent studies later reported tumors in multiple tissues at doses used in those experiments. Whether those findings translate to human risk remains uncertain, and the clinical relevance of the animal data is still debated.
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.
Cardarine is explicitly prohibited by the World Anti-Doping Agency under the class of PPARδ agonists. Its presence in urine or blood samples can be detected using mass spectrometry-based methods, often liquid chromatography-tandem mass spectrometry. Athletes who test positive may face sanctions, including bans from competition. The compound is also regulated as a prescription-only or unapproved drug in many countries. Enforcement varies by jurisdiction, and some regions treat it as a controlled substance. Online sales may occur despite these restrictions, creating quality and legal risks.
| Property | Value | Notes |
|---|---|---|
| Common name | Cardarine | Common internet and media name. |
| Research code | GW501516 | Also written GW-1516. |
| Drug class | PPARδ agonist | Not a selective androgen receptor modulator. |
| Development status | Discontinued | Clinical development halted after rodent cancer findings. |
| Regulatory status | Prohibited in sport | Listed by WADA; not approved as medicine. |
Anti-doping laboratories identify GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the usual matrix, and detection can occur after the parent compound has cleared from blood. The exact detection window depends on dose, formulation, individual metabolism, and assay sensitivity. Because the compound is prohibited at all times, athletes are subject to testing in and out of competition. Analytical methods continue to improve as new metabolites and designer analogs are characterized.
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.
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 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.
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
Cardarine is a common name for GW501516, a synthetic compound studied for its effects on lipid and glucose metabolism. It functions as an agonist at peroxisome proliferator-activated receptor delta, or PPARδ, a nuclear receptor that influences gene expression. The molecule is not a steroid, nor is it a selective androgen receptor modulator. It is also known in research and sports literature as GW-501516 and endurobol. Early laboratory work examined its metabolic activity in cell cultures and animal models.
== Mechanism of action == Ganciclovir (9-[(1,3-dihydroxy-2-propoxy)methyl]guanine) is a potent inhibitor of viruses of the herpes family, including cytomegalovirus (CMV), that are pathogenic for humans and animals. The primary mechanism of ganciclovir action against CMV is inhibition of the replication of viral DNA by ganciclovir-5'-triphosphate (ganciclovir-TP). This inhibition includes a selective and potent inhibition of the viral DNA polymerase. Ganciclovir is metabolized to the triphosphate form by primarily three cellular enzymes: (1) a deoxyguanosine kinase induced by CMV-infected cells; (2) guanylate kinase; and (3) phosphoglycerate kinase. Other nucleotide-metabolizing enzymes may be involved as well. The selective antiviral response associated with ganciclovir treatment is achieved because of the much weaker inhibition of cellular DNA polymerases by ganciclovir-TP. Activity and selectivity are also amplified by the accumulation of ganciclovir-TP in CMV-infected cells.
coding strand Also sense strand, positive (+) sense strand, and nontemplate strand. The strand of a double-stranded DNA molecule whose nucleotide sequence corresponds directly to that of the RNA transcript produced during transcription (except that thymine bases are substituted with uracil bases in the RNA molecule). Though it is not itself transcribed, the coding strand is by convention the strand used when displaying a DNA sequence because of the direct analogy between its sequence and the codons of the RNA product. Contrast template strand; see also sense.
== Structure == LCRs were originally thought to be unstructured and flexible linkers that served to separate the structured (and functional) domains of complex proteins, but they are also capable of forming secondary structures, like helices (more often) and even sheets. They may play a structural role in proteins such as collagens, myosin, keratins, silk, cell wall proteins. Tandem repeats of short oligopeptides that are rich in glycine, proline, serine or threonine are capable of forming flexible structures that bind ligands under certain pH and temperature conditions. Proline is a well-known alpha-helix breaker, however, amino acid repeats composed of proline may form poly-proline helices.
=== Pharmaceutical industry === In the pharmaceutical industry, ICP-MS is used for detecting inorganic impurities in pharmaceuticals and their ingredients. New and reduced maximum permitted exposure levels of heavy metals from dietary supplements, introduced in USP (United States Pharmacopeia) «〈232〉Elemental Impurities—Limits» and USP «〈233〉Elemental Impurities—Procedures», will increase the need for ICP-MS technology, where, previously, other analytic methods have been sufficient.
Sources: en.wikipedia.org
== Side effects == Side effects include sweating, palpitations, loss of consciousness and rarely convulsions due to severe hypoglycemia which may cause coma. If extreme symptoms are present, glucose should be given intravenously. In subjects with no adrenal reserve an Addisonian crisis may occur. For cortisol stimulation, the ACTH stimulation test has much less risk.
=== "Guttergate" === On Friday 24 August 2007, the Seven Network broadcast details obtained from players' confidential medical records on its nightly news program. It allegedly purchased these details for $3,000 from a woman who found them in a gutter outside a medical clinic in Melbourne – leading to the nickname "Guttergate" for the incident. The network said that these records contained details of illicit, non-performance-enhancing drug-taking by players at a particular club in the AFL. The name of the club involved was revealed by Seven on air, but not the names of the players. Seven had promised to reveal the names of the players before the end of the program, but since anonymity was guaranteed by the AFL's three-strikes policy, the AFL obtained a court injunction from the Supreme Court of Victoria to suppress the release of the names – this injunction continues to prevent the publication of any part of the records, including any subsequent publication of the name of the club. At first, Seven vigorously defended its broadcast and stated that it had done so only for the purpose of highlighting the issue of drugs in sport. It challenged the injunction, then faced a backlash both from the AFL and the AFL players themselves. As a result, the players boycotted Seven, refusing to answer any questions posed by its journalists. Seven was not invited to (and, had it still arrived, would have been actively denied entry to) an AFL Players Association (AFLPA) press conference.
=== Parallel thermal shift assays === Recent developments have extended thermal shift approaches to the analysis of ligand interactions in complex mixtures, including intact cells. Initial observations of individual proteins using fast parallel proteolysis (FastPP) showed that stabilization by ligand binding could impart resistance to proteolytic digestion with thermolysin. Protection relative to reference was quantified through either protein staining on gels or western blotting with a labeling antibody directed to a tag fused to the target protein. CETSA, for cellular thermal shift assay, is a method that monitors the stabilization effect of drug binding through the prevention of irreversible protein precipitation, which is usually initiated when a protein becomes thermally denatured. In CETSA, aliquots of cell lysate are transiently heated to different temperatures, following which samples are centrifuged to separate soluble fractions from precipitated proteins. The presence of the target protein in each soluble fraction is determined by western blotting and used to construct a CETSA melting curve that can inform regarding in vivo targeting, drug distribution, and bioavailability. Both FastPP and CETSA generally require antibodies to facilitate target detection, and consequently are generally used in contexts where the target identity is known a priori.
==== Magnetic deflection ==== Thomson first investigated the magnetic deflection of cathode rays. Cathode rays were produced in the side tube on the left of the apparatus and passed through the anode into the main bell jar, where they were deflected by a magnet. Thomson detected their path by the fluorescence on a squared screen in the jar. He found that whatever the material of the anode and the gas in the jar, the deflection of the rays was the same, suggesting that the rays were of the same form whatever their origin.
In contrast to short term sample storage at +4 to −20 °C (39 to −4 °F) by using standard refrigerators or freezers, many molecular biology or life science laboratories need long-term cryopreservation (including "cold chain" and/or "colder chain" infrastructures) for biological samples like DNA, RNA, proteins, cell extracts, or reagents. To reduce the risk of sample damage, these types of samples need extremely low temperatures of −80 to −86 °C (−112 to −123 °F). Mammalian cells are often stored in dewars containing liquid nitrogen at −196 °C (−320.8 °F). Cryogenic chest freezers can achieve temperatures down to −150 °C (−238 °F) to −152 °C (−242 °F) and may include a liquid nitrogen backup. Biological samples in ULT freezers are often stored in polymer tubes and microtubes, generally inside storage boxes that are commonly made of cardboard, polymer plastics or other materials. Microtubes are placed in storage boxes containing a grid of dividers that typically permit 64, 81, or 100 tubes to be stored. Standard ULT freezers can store approximately 350 to 450 microtube boxes.
Sources: en.wikipedia.org
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.
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.
No. It remains an investigational compound without approved therapeutic labeling. Sports regulators prohibit its use, and health agencies have warned against consuming it.
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.