LC-MS/MS 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 2026-01-26. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Prohibited in sport | Listed by WADA as a PPARδ agonist. |
| Typical detection matrix | Urine | Most common sample for anti-doping analysis. |
| Common analytical method | LC-MS/MS | Liquid chromatography-tandem mass spectrometry. |
| Common synonyms | GW501516, GSK-516, endurobol | Names found in research and fitness contexts. |
| Typical detection window | Variable | Depends on dose, route, and individual metabolism. |
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.
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.
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.
Preclinical research reported that GW501516 increased running endurance in mice and improved lipid profiles in some animal species. Early human trials explored effects on high-density lipoprotein cholesterol, triglycerides, and glucose handling, but the program was discontinued. Published human data are sparse and do not establish efficacy for any condition. Studies also examined PPAR delta in cancer biology, with conflicting findings across models. The relationship between receptor activation, tissue context, and disease risk remains an active area of investigation.
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.
=== Radiation side-effects === Diagnostic treatment involving technetium-99m will result in radiation exposure to technicians, patients, and passers-by. Typical quantities of technetium administered for immunoscintigraphy tests, such as SPECT tests, range from 400 to 1,100 MBq (11 to 30 mCi) (millicurie or mCi; and Mega-Becquerel or MBq) for adults. These doses result in radiation exposures to the patient around 10 mSv (1000 mrem), the equivalent of about 500 chest X-ray exposures. This level of radiation exposure is estimated by the linear no-threshold model to carry a 1 in 1000 lifetime risk of developing a solid cancer or leukemia in the patient. The risk is higher in younger patients, and lower in older ones. Unlike a chest x-ray, the radiation source is inside the patient and will be carried around for a few days, exposing others to second-hand radiation. A spouse who stays constantly by the side of the patient through this time might receive one thousandth of patient's radiation dose this way. The short half-life of the isotope allows for scanning procedures that collect data rapidly. The isotope is also of a very low energy level for a gamma emitter. Its ~140 keV of energy make it safer for use because of the substantially reduced ionization compared with other gamma emitters. The energy of gammas from 99mTc is about the same as the radiation from a commercial diagnostic X-ray machine, although the number of gammas emitted results in radiation doses more comparable to X-ray studies like computed tomography.
== External links == "Glucagon Receptor Family: GLP-1". The International Union of Basic and Clinical Pharmacology, The British Pharmacological Society, The University of Edinburgh. International Union of Basic and Clinical Pharmacology. Archived from the original on 2016-03-03. Retrieved 2007-10-25. glucagon-like+peptide+receptor at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Overview of all the structural information available in the PDB for UniProt: P43220 (Glucagon-like peptide 1 receptor) at the PDBe-KB.
== Temperature stability == After an hour at 50 °C (122 °F), 83% of the enzyme remains, while at 40 °C (104 °F), practically 100% remains. The proteolytic activity of concentrated bromelain solutions remains relatively stable for at least 1 week at room temperature, and multiple freeze-thaw cycles or exposure to the digestive enzyme trypsin have little effect on it.
=== Pain scale === Acute or chronic pain can be directly measured by pain scales such as the numerical rating scale (NRS) and visual analog scale (VAS). A serial pain scale from 0 (no pain) to 10 (worst pain imaginable) can quantify pain intensity. It can also monitor symptom improvement in nursing women who experience persistent nipple pain for at least two weeks postpartum.
Sources: en.wikipedia.org
=== Hypertension-induced cardiovascular disorders === In a model where FFAR2 and FFAR3 were both deleted, these animals had an exaggerated response to hypertension, with higher fibrosis in the kidney; this was explained by a breakdown in the gut epithelial barrier and activation of the immune system via LPS/TLR4 binding. Studies in humans have found that individuals undergoing hemodialysis using dialysis solutions that contain acetic acid often develop hypotension; the role of FFAR3 in this response, if any, was not investigated. A study of 69 individuals (55.1% women, mean age 59.8 years) found that arterial stiffness was associated with lower levels of FFAR3 and FFAR2 in circulating blood immune cells (particularly regulatory T cells which are known to be protective in murine models of hypertension). Overall, the mouse studies suggest that FFAR3 contributes to suppressing hypertension and its subsequent effects on the heart in mice and that SC-FA-activated FFAR3 and/or FFAR2 may have vasodilatory actions and thereby suppress the development of hypertension and hypertension-induced arterial stiffness in humans. Further studies in humans are needed to investigate the latter possibilities.
=== Systems biology === Advances in quantitative proteomics would clearly enable more in-depth analysis of cellular systems. Another research frontier is the analysis of single cells, and protein covariation across single cells which reflects biological processes such as protein complex formation, immune functions, as well as cell cycle and priming of cancer cells for drug resistance Biological systems are subject to a variety of perturbations (cell cycle, cellular differentiation, carcinogenesis, environment (biophysical), etc.). Transcriptional and translational responses to these perturbations results in functional changes to the proteome implicated in response to the stimulus. Therefore, describing and quantifying proteome-wide changes in protein abundance is crucial towards understanding biological phenomenon more holistically, on the level of the entire system. In this way, proteomics can be seen as complementary to genomics, transcriptomics, epigenomics, metabolomics, and other -omics approaches in integrative analyses attempting to define biological phenotypes more comprehensively. As an example, The Cancer Proteome Atlas provides quantitative protein expression data for ~200 proteins in over 4,000 tumor samples with matched transcriptomic and genomic data from The Cancer Genome Atlas. Similar datasets in other cell types, tissue types, and species, particularly using deep shotgun mass spectrometry, will be an immensely important resource for research in fields like cancer biology, developmental and stem cell biology, medicine, and evolutionary biology.
Electromagnetic alternating fields have been used in medicine since 1764, mainly for heating and increasing blood circulation (diathermy, short-wave therapy) to improve wound and bone healing. The relevant radiation protection is regulated by the Medical Devices Act together with the Medical Devices Operator Ordinance. The Medical Devices Act came into force in Germany on January 14, 1985. It divided the medical devices known at that time into groups according to their degree of risk to the patient. The Medical Devices Ordinance regulated the handling of medical devices until January 1, 2002, when it was replaced by the Medical Devices Act. When ionizing radiation is used in medicine, the benefit must outweigh the potential risk of tissue damage (justifiable indication). For this reason, radiation protection is of great importance. The design should be optimized according to the ALARA (As Low As Reasonably Achievable) principle as soon as an application is described as suitable. Since 1996, the European ALARA Network (EAN), founded by the European Commission, has been working on the further implementation of the ALARA principle in radiation protection.
Sources: en.wikipedia.org
Renee and her son Sekou walk Jasmine down the aisle at her wedding with Crosby. Renee lives with Crosby, Jasmine, and Jabbar briefly when she loses her job, but moves out after a disagreement on how they discipline Jabbar. Renee insists that baby Aida should be baptized, and holds a baptism brunch at her place. She gets along well with Camille, and at the pre-baptism dinner at Zeek and Camille's house, says she always enjoys dinners that Camille holds. Gordon Flint (William Baldwin) was Adam's boss until he sold the company. When Sarah became an intern at Adam's company, she and Gordon became romantically involved, which caused friction between Adam and Sarah. Gordon is invited by Sarah to the Braverman Thanksgiving dinner, but that morning, when telling Adam he sold the company, Adam asks him not to come to the dinner. Gordon comes anyway, and at the football game that afternoon, tensions between Adam and Gordon come to a head. Mike (Kevin Alejandro), aka "Forklift Mike", drives a forklift at T&S Footwear. Mike recommends a band for Sarah to take Amber and Kelsey to see, at a club where Mike knows the man at the door. Alex (Michael B. Jordan) is Haddie's on again, off again boyfriend, whom she met while she volunteering at the food bank he currently manages. He is a recovering alcoholic and three years older than Haddie, so Haddie's parents initially disapprove of the relationship. Cory Smith (Anthony Carrigan) is Adam's new boss when Gordon sells the company. His youth and radical approach to business are disconcerting to Adam.
== History == Life Length was established on September 28, 2010 by Stephen J. Matlin and Dr. María Blasco Marhuenda, as a spin-off from the Spanish National Cancer Research Centre. The founders had the objective to commercialize Blasco's HT Q-FISH conceptual work. In 2016, the company obtained CLIA certification, a U.S. government accreditation for clinical laboratories, becoming the only laboratory in Spain with this certification. In 2017, the ONCOCHECK project, which involves a series of clinical studies focused on cancer diagnostics, received €3.1 million in funding from the European Union's Horizon 2020 research and innovation program. In 2021, Life Length opened a clinic at Paseo del General Martinez Campos, 46, in Madrid. In 2022, the company's prostate cancer diagnostic tool received approval from the Spanish Agency for Medicines and Health Products (AEMPS). The same year, the company launched HEALTHTAV, a new product in its portfolio.
== E == E1cB elimination reaction Eder reaction Edman degradation Eglinton reaction Ehrlich–Sachs reaction Einhorn variant Einhorn–Brunner reaction Elbs persulfate oxidation Elbs reaction Electrochemical fluorination Electrocyclic reaction Electrophilic halogenation Electrophilic amination Elimination reaction Emde degradation Emmert reaction Enders SAMP/RAMP hydrazone-alkylation reaction Ene reaction Enyne metathesis Epoxidation Erlenmeyer synthesis, Azlactone synthesis Erlenmeyer–Plöchl azlactone and amino-acid synthesis Eschenmoser fragmentation Eschenmoser sulfide contraction Eschweiler–Clarke reaction Ester pyrolysis Ether cleavage Étard reaction Evans aldol Evans–Saksena reduction Evans–Tishchenko reaction
Sources: en.wikipedia.org
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.
Detection usually uses liquid chromatography-tandem mass spectrometry after sample cleanup. Laboratories look for the parent compound or metabolites. The method requires validated reference standards and controls.
Legality varies by country. In many places it is an unapproved drug and cannot be legally sold for human consumption. Purchasing from online vendors carries legal and quality risks.
Cardarine is an investigational synthetic compound that acts as a PPARδ agonist. It is also known as GW501516 and has been studied mainly in preclinical research. It is not an approved medicine.