GW501516 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 2026-07-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
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 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.
A persistent misconception is that cardarine is a fat-burning drug or a safe alternative to anabolic steroids. No approved therapeutic product exists, and human safety data are limited. The tumor findings in rodents remain a central concern in scientific reviews. Products sold online may contain inaccurate labels, impurities, or different compounds entirely, which complicates any assessment of effects. Independent testing of such products has reported frequent mislabeling. For these reasons, discussions in the literature emphasize risks and unknowns rather than benefits.
Cardarine is not approved for human therapeutic use in any major jurisdiction. It appears on the World Anti-Doping Agency Prohibited List as a PPARδ agonist within the hormone and metabolic modulators category. Sports organizations test for it because it has been detected in athlete samples and seized products. Regulatory actions against marketed research chemical versions have occurred in several countries, though enforcement varies. Availability through unregulated channels complicates oversight.
| Property | Value | Notes |
|---|---|---|
| WADA classification | S4 Hormone and Metabolic Modulators | Prohibited at all times in sport. |
| Drug approval status | Not approved in major jurisdictions | No accepted therapeutic indication. |
| Common detection method | LC-MS/MS | Detects parent compound and metabolites. |
| Typical test matrix | Urine or blood | Urine is common in anti-doping testing. |
| Product labeling | Research chemical or supplement | Often not independently verified. |
Clinical development stopped after rodent studies showed tumors at multiple sites. Whether those findings predict human cancer risk remains an open question, but they led sponsors to discontinue programs. Human safety data are limited to small, short-term studies that were not designed to assess cancer risk. Reported effects in those studies included changes in blood lipids, but the evidence is insufficient for medical use. Long-term consequences of nonmedical use are not well characterized. Questions about dose, duration, and individual susceptibility remain unresolved.
Cardarine is a common name for GW501516, an investigational compound developed in the 1990s for metabolic conditions. It acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in lipid and energy metabolism. The compound is frequently mislabeled as a selective androgen receptor modulator, or SARM, but its molecular target is different. GW501516 reached early clinical testing before development was discontinued. It has no approved therapeutic use in any country. The name cardarine is not a formal international nonproprietary name.
Regulatory treatment varies, but cardarine is not approved as a medicine. Sports authorities list GW501516 as a prohibited substance, and it is banned at all times under the World Anti-Doping Agency code. Many countries restrict sales for human consumption, while online vendors market it as a research chemical. Such products may lack purity data, and their actual contents can differ from the label. Purchasing or possessing cardarine may carry legal consequences depending on jurisdiction. The compound is not a dietary supplement ingredient in regulated markets.
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.
Safety concerns emerged from long-term animal studies. In rodents given the compound for extended periods, researchers found an increased incidence of certain cancers, including liver and bladder tumors. These findings contributed to the discontinuation of clinical development. Whether similar risks apply to short-term or low-level exposure in humans is not established, and controlled human safety data are limited. The relevance of high-dose rodent carcinogenicity findings to human use remains a subject of debate.
== United Kingdom == The Public Health Laboratory Service (PHLS) was established as part of the National Health Service in 1946. An Emergency Public Health Laboratory Service was established in 1940 as a response to the threat of bacteriological warfare. There was originally a central laboratory at Colindale and a network of regional and local laboratories. By 1955 there were about 1000 staff. These laboratories were primarily preventive with an epidemiological focus. They were, however, in some places located with hospital laboratories which had a diagnostic focus. The PHLS was replaced by the Health Protection Agency in 2003; the HPA was disbanded and in its stead was constituted Public Health England, which later became the UK Health Security Agency in 2021.
== Preparation == TCFH is commercially available. It may be prepared from tetramethylurea using a chlorinating agent such as oxalyl chloride, thionyl chloride or phosphorus oxychloride followed by a salt metathesis reaction.
One gram of poppy seeds contains up to 33 micrograms of morphine and 14 micrograms of codeine, and the Substance Abuse and Mental Health Services Administration in the United States formerly mandated that all drug screening laboratories use a standard cutoff of 300 nanograms per milliliter in urine samples. A single poppy seed roll (0.76 grams of seeds) usually did not produce a positive drug test, but a positive result was observed from eating two rolls. A slice of poppy seed cake containing nearly five grams of seeds per slice produced positive results for 24 hours. Such results are viewed as false positive indications of drug use and were the basis of a legal defense. On November 30, 1998, the standard cutoff was increased to 2000 nanograms (two micrograms) per milliliter. Confirmation by gas chromatography-mass spectrometry will distinguish amongst opium and variants including poppy seeds, heroin, and morphine and codeine pharmaceuticals by measuring the morphine:codeine ratio and looking for the presence of noscapine and acetylcodeine, the latter of which is only found in illicitly produced heroin, and heroin metabolites such as 6-monoacetylmorphine.
Luspatercept, sold under the brand name Reblozyl, is a medication used for the treatment of anemia in beta thalassemia and myelodysplastic syndromes. The US Food and Drug Administration (FDA) considers it to be a first-in-class medication.
Its activation by the neurotransmitter glutamate facilitates rapid neuronal communication, essential for various brain functions, including learning and memory. Its name is derived from the ability to be activated by the artificial glutamate analog AMPA. The receptor was initially named the "quisqualate receptor" by Watkins and colleagues after the naturally occurring agonist quisqualate. Later, the receptor was designated as the "AMPA receptor" following the development of the selective agonist AMPA by Tage Honore and colleagues at the Royal Danish School of Pharmacy in Copenhagen. The GRIA2-encoded AMPA receptor ligand binding core (GluA2 LBD) was the first glutamate receptor ion channel domain to be crystallized.
Sources: en.wikipedia.org
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=== Bid to return to coaching Essendon === Towards the end of the 2026 AFL season, Hird made a bid to return as coach for Essendon in 2027. However, the board eventually decided to select Mark McVeigh, who played alongside with, and was coached by, Hird at Essendon.
=== Pain in mammals === In mutant yellow-orange mice and human redheads, both with nonfunctional MC1R, both genotypes display reduced sensitivity to noxious stimuli and increased analgesic responsiveness to morphine-metabolite analgesics. These observations suggest a role for mammalian MC1R outside the pigment cell, though the exact mechanism through which the protein can modulate pain sensation is not known. In a certain genetic background in mice it has been reported that animals lacking MC1R had increased tolerance to capsaicin acting through the TRPV1 receptor and decreased response to chemically induced inflammatory pain. Humans with MC1R mutations have been reported to need approximately 20% more inhalational anaesthetic than controls. Lidocaine was reported to be much less effective in reducing pain in another study of humans with MC1R mutations
AMP + diphosphate + NAD+ The 3 substrates of this enzyme are ATP, deamido-NAD+, and NH3, whereas its 3 products are AMP, diphosphate, and NAD+. This enzyme belongs to the family of ligases, specifically those forming carbon-nitrogen bonds as acid-D-ammonia (or amine) ligases (amide synthetase). The systematic name of this enzyme class is deamido-NAD+:ammonia ligase (AMP-forming). Other names in common use include NAD+ synthetase, NAD+ synthetase, nicotinamide adenine dinucleotide synthetase, and diphosphopyridine nucleotide synthetase. This enzyme participates in nicotinate and nicotinamide metabolism and nitrogen metabolism.
== Structure == Sequence alignment of TCTP sequences from more than 30 different species reveals a high degree of conservation over a long period of evolution. The solution structure of TCTP from yeast, Schizosaccharomyces pombe has been determined by NMR spectroscopy which indicated that this protein is structurally similar to two small guanine nucleotide-free chaperones, namely Mss4 and Dss4. TCTP and Mss4/Dss4 are now therefore structurally grouped into one protein superfamily. Translationally controlled tumor protein (TCTP) is involved in a wide range of molecular interactions with biological and nonbiological partners of various chemical compositions such as proteins, peptides, nucleic acids, carbohydrates, or small molecules. TCTP is therefore an important and versatile binding platform. Many of these protein–protein interactions have been validated, albeit only few received an in-depth structural characterization. In TCTP/tpt1 - Remodeling Signaling from Stem Cell to Disease, focus is on the structural analysis of TCTP and the review of the available literature regarding its interaction network from a structural perspective. The structure of TCTP has a very complex topology composed of three alpha helices, and eleven beta strands arranged in two small beta-sheets, one larger than the other.
Sources: en.wikipedia.org
Anti-doping laboratories typically use LC-MS/MS to detect GW501516 and its metabolites in urine. The method is sensitive and can identify the compound at low concentrations. Detection depends on sample timing, metabolism, and the specific assay.
Legality varies by country and context. It lacks marketing approval as a medicine in major countries. Sports organizations prohibit its use at all times.
A certificate of analysis may report identity, purity, and testing methods for a specific batch. It does not guarantee safety or legal status. Independent verification can confirm whether the material matches the label.
No. Cardarine has not received approval for human therapeutic use in major jurisdictions. It remains an investigational compound.