If you have been reading about LC-MS/MS 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 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Analytical laboratories typically identify cardarine and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is a common matrix in anti-doping testing, while blood and tissue may be used in research settings. Detection windows depend on the assay, the sample matrix, and the compound's metabolism. Because cardarine is extensively metabolized, laboratories often target specific metabolites to improve sensitivity and confirmation. Reference standards are required for reliable quantification. Method validation includes checks for selectivity, linearity, and carryover.
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 |
|---|---|---|
| Common synonyms | GW501516; GW-1516; endurobol | GW501516 is the research code |
| Drug class | PPARδ agonist | Not a selective androgen receptor modulator |
| Molecular formula | C21H18F3NO3S2 | Established chemical formula |
| Molar mass | 453.5 g/mol | Calculated from the formula |
| Regulatory status | Prohibited in sport; not approved as medicine | Status varies by country |
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.
Stability of GW501516 depends on form, temperature, light exposure, and moisture. Solid reference material is typically stored frozen or refrigerated in a desiccator and protected from light. Solutions in organic solvents such as dimethyl sulfoxide are often kept frozen in aliquots to reduce freeze-thaw cycling. Aqueous solubility is low, so aqueous stock solutions can be difficult to prepare without cosolvents. Degradation may appear as changes in chromatographic purity or mass spectral signal. Stability studies are needed to establish shelf life for any specific preparation.
Quality assessment for cardarine samples usually combines identity, purity, and impurity testing. Nuclear magnetic resonance spectroscopy and mass spectrometry can confirm molecular structure, while high-performance liquid chromatography estimates purity. Certificates of analysis from testing laboratories may list these results, but they do not establish safety or legality. In the absence of approved manufacturing, products sold online may contain the wrong compound, variable amounts, or unlisted contaminants. Independent verification is therefore central to analytical work and to interpreting any reported biological activity.
Laboratory detection of GW501516 commonly uses liquid chromatography coupled with tandem mass spectrometry. The method can identify the parent compound or its metabolites in urine and blood after sample cleanup. Protein precipitation, solid-phase extraction, or enzymatic hydrolysis may precede analysis, depending on the matrix. Reference standards are required for accurate quantification and confirmation. Because the compound is not approved, testing often occurs in anti-doping, forensic, or research settings rather than routine clinical care. Results are reported with limits of detection and quantification.
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.
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.
The cars were cleaned with hot water or steam. Depending on the cargo, the cars might have undergone four hours of "pre-cooling" before loading, which entailed blowing in cold air through one ice hatch and allowing the warmer air to be expelled through the other hatches. The practice, dating back almost to the refrigerator car's inception, saved ice and resulted in fresher cargo. The cars' ice bunkers were filled, either manually from an icing dock, via mechanical loading equipment, or (in locations where demand for ice was sporadic) using specially designed field icing cars. The cars were delivered to the shipper for loading, and the ice was topped off. Depending on the cargo and destination, the cars may have been fumigated. The train would depart for the eastern markets. The cars were re-iced in transit approximately once a day. Upon reaching their destination, the cars were unloaded. If in demand, the cars would be returned empty to their point of origin. If not in demand, the cars would be cleaned and possibly used for a dry shipment.
=== Strong magnetic fields === In magnetic fields above 10 tesla, additional plateaus of the Hall conductivity at σxy = νe2/h with ν = 0, ±1, ±4 are observed. A plateau at ν = 3 and the fractional quantum Hall effect at ν = 1/3 were also reported. These observations with ν = 0, ±1, ±3, ±4 indicate that the four-fold degeneracy (two valley and two spin degrees of freedom) of the Landau energy levels is partially or completely lifted.
Mean platelet volume (MPV) is a machine-calculated measurement of the average size of platelets found in blood and is typically included in blood tests as part of the CBC. Since the average platelet size is larger when the body is producing increased numbers of platelets, the MPV test results can be used to make inferences about platelet production in bone marrow or platelet destruction problems. An increased mean platelet volume (MPV) increases the risk to suffer a heart disease MPV may be higher when there is destruction of platelets. This may be seen in immune thrombocytopenic purpura (ITP), myeloproliferative diseases and Bernard–Soulier syndrome. It may also be related to pre-eclampsia and recovery from transient hypoplasia. Abnormally low MPV values may correlate with thrombocytopenia when it is due to impaired production of megakaryocytes in the bone marrow, such as in aplastic anemia. A low MPV may indicate inflammatory bowel disease (IBD), such as Crohn's disease and ulcerative colitis. A high MPV is also a bad prognostic marker in patients with sepsis or septic shock. In addition, low MPV may correlate with abnormally small platelet size, sometimes a symptom of a spectrum referred to as Wiskott–Aldrich syndrome (WAS), caused by a genetic mutation of the WAS gene. Sample for MPV testing is obtained in a Lavender-Top EDTA tube. A typical range of platelet volumes is 7.2 - 11.7 fL (femtolitre), equivalent to spheres 2.65 to 2.9 μm in diameter.
== Function (translocation) == Signal peptides function to prompt a cell to translocate the protein, usually to the cellular membrane. In prokaryotes, signal peptides direct the newly synthesized protein to the SecYEG protein-conducting channel, which is present in the plasma membrane. A homologous system exists in eukaryotes, where the signal peptide directs the newly synthesized protein to the Sec61 channel, which shares structural and sequence homology with SecYEG, but is present in the endoplasmic reticulum. Both the SecYEG and Sec61 channels are commonly referred to as the translocon, and transit through this channel is known as translocation. While secreted proteins are threaded through the channel, transmembrane domains may diffuse across a lateral gate in the translocon to partition into the surrounding membrane.
Sources: en.wikipedia.org
== Cost effectiveness == A 2007 study found that the live vaccine is likely to be cost-effective in the US, projecting an annual savings of US$82 to US$103 million in healthcare costs with cost-effectiveness ratios ranging from US$16,229 to US$27,609 per quality-adjusted life year gained. In 2007, the live vaccine was officially recommended in the US for healthy adults aged 60 and over, but is no longer given out in the United States as of 2020, given the superiority of Shingrix. In Canada the cost of Shingrix is about CA$300 for the two doses. This likely represents a more cost effective intervention than the live vaccine given its lower cost and increased effectiveness.
There have been increasing public calls for global collective action to address the threat, including a proposal for an international treaty on antimicrobial resistance. Further detail and attention is still needed to recognize and measure trends in resistance on the international level; the idea of a global tracking system has been suggested but implementation has yet to occur. A system of this nature would provide insight to areas of high resistance as well as information necessary for evaluating programs, introducing interventions and other changes made to fight or reverse antibiotic resistance.
== External links == Extraordinary You: Case studies of Healthcare scientists in the UK's National Health Service National Institute of Environmental Health Sciences The US National Library of Medicine National Health Service
Sources: en.wikipedia.org
No. Cardarine is GW501516, a PPARδ agonist, while SARMs act on androgen receptors. The two classes are often grouped in informal discussions despite different mechanisms.
No. It has no approved medical indication in any country. Regulatory agencies have not cleared it for treatment or prevention of any condition.
Early clinical work stopped after rodent carcinogenicity findings. Those animal results raised concerns about long-term human risk, although direct human evidence is lacking. The human relevance of the tumors remains an open scientific question.
No. Cardarine has not received approval for human therapeutic use in major jurisdictions. It remains an investigational compound.