LC-MS/MS 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 2025-08-17. Where a claim depends on a specific study, the study is described rather than over-claimed.
At the molecular level, GW501516 binds and activates PPARδ, a nuclear receptor that regulates transcription. Activation shifts expression of genes involved in fatty acid oxidation, energy expenditure, and lipid transport in skeletal muscle and liver. Animal studies report increased endurance and altered lipid profiles after exposure. Human data are limited to small trials and do not establish long-term safety or efficacy. PPARδ also has roles in cell proliferation, so the relationship between activation and cancer risk remains an open question.
Published literature on cardarine includes in vitro assays, rodent experiments, and a small number of human studies. Reports describe effects on exercise capacity and lipid metabolism in animals, while human evidence is sparse. Many online descriptions present the compound as a proven endurance aid, a claim not supported by regulatory approval or large clinical trials. Analytical studies focus on identifying the parent compound and its metabolites in biological samples. Important uncertainties include species differences, dose-response relationships, and the relevance of rodent tumor findings to humans.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Common name | Cardarine | Also called GW501516 and endurobol. |
| Chemical formula | C21H18F3NO3S2 | Molecular weight about 453.5 g/mol. |
| Appearance | White to off-white solid | Form depends on synthesis and purity. |
| Solubility | Soluble in DMSO and ethanol | Low solubility in water. |
| Typical storage | -20 °C, desiccated, protected from light | Common for research chemicals. |
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.
Published human data are sparse and mostly come from early-phase trials. Those studies examined short-term changes in lipids, glucose, and exercise capacity, but they were not large enough to establish efficacy or long-term safety. Some animal experiments reported increased running endurance, yet such findings do not prove a performance benefit in people. Anti-doping laboratories detect GW501516 and its metabolites in urine or blood using liquid chromatography-tandem mass spectrometry. Detection windows depend on dose, sample type, and individual metabolism. The method is sensitive enough to identify trace residues in tested samples.
Laboratory handling focuses on identity, purity, and stability. Reference standards are typically stored cold and dry, protected from light, because solutions can degrade over time. Analytical checks may use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Impurities and related substances can be separated chromatographically and compared with a known standard. Because cardarine is not an approved drug, compendial monographs are absent, and laboratories often rely on in-house methods. Reported purity varies among unregulated products and should not be assumed from a label.
GW501516 binds and activates PPARδ, a nuclear receptor that influences transcription of genes involved in fatty acid oxidation and energy use. Activation shifts some metabolic pathways in preclinical models, which is why the compound has been studied for lipid disorders and exercise-related endpoints. The exact downstream effects in humans are incompletely mapped. PPARδ is expressed in many tissues, including skeletal muscle, liver, and adipose tissue, so broad activation may have varied consequences. Researchers continue to examine how selective or partial activation might alter the balance between benefits and risks.
In July 2008, the whole site was rebranded under the Edge title, as that was the senior of the two brands. In May 2014 it was reported that Future intended to close the websites of Edge, Computer and Video Games and their other videogame publications; in December 2014, it was confirmed that the C&VG website would close and its content would instead be published at GamesRadar, and in January 2015, it was announced that the same would happen to the Edge website. Between 2015 and 2018, Edge articles were occasionally republished on Kotaku UK. Edge has been redesigned three times since the magazine launched. The first redesign occurred in 1999; the second in 2004; and the third in 2011. The first redesign altered the magazine's dimensions to be wider than the original shape. The latest design changes the magazine's physical dimensions for the second time, and introduces a higher quality of paper stock than was previously used.
== Chemistry == Like all ergopeptides, bromocriptine is a cyclol; two peptide groups of its tripeptide moiety are crosslinked, forming the >N-C(OH)< juncture between the two rings with the amide functionality. Bromocriptine is a semisynthetic derivative of a natural ergot alkaloid, ergocryptine (a derivative of lysergic acid), which is synthesized by bromination of ergocryptine using N-bromosuccinimide.
===== Anguimorpha ===== Clade Paleoanguimorpha Family Shinisauridae Shinisaurus crocodilurus, Chinese crocodile lizard, (2017) Clade Neoanguimorpha Family Helodermatidae Heloderma charlesbogerti, Guatemalan beaded lizard, (2022) Family Anguidae Dopasia gracilis, Burmese glass lizard, (2015)
==== Procedure ==== A blood smear is prepared by placing a drop of blood on a microscope slide and using a second slide held at an angle to spread the blood and pull it across the slide, forming a "feathered edge" consisting of a single layer of cells at the end of the smear. This may be done by hand or using an automated slide maker coupled to a hematology analyzer. The slide is treated with a Romanowsky stain, commonly Wright's stain or Wright-Giemsa, and examined under the microscope. The smear is examined in a systematic pattern, scanning from side to side within the feathered edge and counting cells consecutively. The differential is typically performed at 400x or 500x magnification, but 1000x magnification may be used if abnormal cells are present. Cells are identified based on their morphologic features, such as the size and structure of their nucleus and the colour and texture of their cytoplasm. This allows abnormal cell types and changes in cellular appearance to be identified. In most cases, the microscopist counts 100 white blood cells, but 200 may be counted for better representation if the white blood cell count is high. The manual differential count produces percentages of each cell type, which can be multiplied by the total white blood cell count from the analyzer to derive the absolute values. The manual differential can be partially automated with digital microscopy software, which uses artificial intelligence to classify white blood cells from photomicrographs of the blood smear. However, this technique requires confirmation by manual review.
== Analysis and evaluation of results == Data analysis and evaluation of results is the most important part of every microarray experiment. After scanning the microarray slides, the scanner records a 20-bit, 16-bit or 8-bit numeric image in tagged image file format (*.tif). The .tif-image enables interpretation and quantification of each fluorescent spot on the scanned microarray slide. This quantitative data is the basis for performing statistical analysis on measured binding events or peptide modifications on the microarray slide. For evaluation and interpretation of detected signals an allocation of the peptide spot (visible in the image) and the corresponding peptide sequence has to be performed. The data for allocation is usually saved in the GenePix Array List (.gal) file and supplied together with the peptide microarray. The .gal-file (a tab-separated text file) can be opened using microarray quantification software-modules or processed with a text editor (e.g. notepad) or Microsoft Excel. This "gal" file is most often provided by the microarray manufacturer and is generated by input txt files and tracking software built into the robots that do the microarray manufacturing.
Sources: en.wikipedia.org
== Diagnosis == PD diagnosis is based primarily on the presence and position of ulcers on the skin, as well as identifying particular protein markers in urine. To confirm the diagnosis, a blood test is required to measure prolidase activity.
== Mineralization of bone == The mechanisms of mineralization are not fully understood. Fluorescent, low-molecular weight compounds such as tetracycline or calcein bind strongly to bone mineral, when administered for short periods. They then accumulate in narrow bands in the new bone. These bands run across the contiguous group of bone-forming osteoblasts. They occur at a narrow (sub-micrometer) mineralization front. Most bone surfaces express no new bone formation, no tetracycline uptake and no mineral formation. This strongly suggests that facilitated or active transport, coordinated across the bone-forming group, is involved in bone formation, and that only cell-mediated mineral formation occurs. That is, dietary calcium does not create mineral by mass action. The mechanism of mineral formation in bone is clearly distinct from the phylogenetically older process by which cartilage is mineralized: tetracycline does not label mineralized cartilage at narrow bands or in specific sites, but diffusely, in keeping with a passive mineralization mechanism. Osteoblasts separate bone from the extracellular fluid by tight junctions by regulated transport. Unlike in cartilage, phosphate and calcium cannot move in or out by passive diffusion, because the tight osteoblast junctions isolate the bone formation space. Calcium is transported across osteoblasts by facilitated transport (that is, by passive transporters, which do not pump calcium against a gradient).
Ehlers–Danlos syndromes (EDS) are a group of 13 genetic connective tissue disorders. Symptoms often include loose joints; joint pain; stretchy, velvety skin; and abnormal scar formation. These may be noticed at birth or in early childhood. Complications may include aortic dissection, joint dislocations, scoliosis, chronic pain, or early osteoarthritis. The existing classification was last updated in 2017, when a number of rarer forms of EDS were added. EDS occurs due to mutations in one or more of the 19 particular genes which can contribute to the condition. The specific gene affected determines the type of EDS, though the genetic causes of hypermobile Ehlers–Danlos syndrome (hEDS) are still unknown. Some cases result from a new variation occurring during early development. In contrast, others are inherited in an autosomal dominant or recessive manner. Typically, these variations result in defects in the structure or processing of the protein collagen or tenascin. Diagnosis is often based on symptoms, particularly hEDS, but people may initially be misdiagnosed with somatic symptom disorder, depression, or myalgic encephalomyelitis/chronic fatigue syndrome. Genetic testing can be used to confirm all types of EDS except hEDS, for which a genetic marker has yet to be discovered. A cure is not yet known, and treatment is supportive in nature. Physical therapy and bracing may help strengthen muscles and support joints.
The wound-healing process is not only complex but fragile, and it is susceptible to interruption or failure leading to the formation of non-healing chronic wounds. Factors that contribute to non-healing chronic wounds are diabetes, venous or arterial disease, infection, and metabolic deficiencies of old age. Wound care encourages and speeds wound healing via cleaning and protection from reinjury or infection. Depending on each patient's needs, it can range from the simplest first aid to entire nursing specialties such as wound, ostomy, and continence nursing and burn center care.
Sheep, lamb and hog casings are available "tubed" where each strand is put on a plastic tube which allows the sausage maker to easily place the casing on the stuffing horn; in recent years these tubes have been modified so they break open along a seam and the operator can pull them out at the back of the horn allowing greater efficiency; these are referred to in the industry as "zip tubes", due to the zipper-like nature of the seam. These tubed casings are then packed in plastic nets, usually two per net, and packed in plastic drums, which are then filled with a saturated salt brine, usually 200 per drum. These are available in all diameters and in lengths greater than 3 meters (as 2-meter or shorter pieces are cost prohibitive to tube). Sheep, lamb, and hog casings are also available loose in brine in a vacuum sealed plastic pack; commonly referred to as "vacuum packs", these are primarily used by small- to medium-sized sausage makers who use less than 100 hanks per month of casing. The appeal of vacuum packs is the ease of use, their shorter strand length for hand stuffing (all sausage makers who do not use automatic sausage stuffing and linking machines) and their shelf life; they only need to be opened as needed so the sausage maker does not need to worry that they will not use their opened casings prior to a decrease in quality. These are available in all diameters and in put ups from short up to medium length, about 6 meter minimum, with a maximum length of about 14 meters. Sheep, lamb and hog casings are also available in a net, commonly referred to as net pack.
Sources: en.wikipedia.org
== Further reading == Spagnolo, Paolo; Cordier, Jean-François; Cottin, Vincent (2016-02-25). "Connective tissue diseases, multimorbidity and the ageing lung". European Respiratory Journal. 47 (5): 1535–1558. doi:10.1183/13993003.00829-2015. hdl:11577/3214636. ISSN 0903-1936. PMID 26917611. Baildam, Eileen (2014). "Rare connective tissue diseases in childhood". Paediatrics and Child Health. 24 (2): 51–57. doi:10.1016/j.paed.2013.12.005.
=== Radionuclide === As 241Am has a half-life roughly similar to 238Pu (432.2 years vs. 87 years), it has been proposed as an active element of radioisotope thermoelectric generators, for example in spacecraft. Although americium produces less heat and electricity – the power yield is 114.7 mW/g for 241Am and 6.31 mW/g for 243Am (cf. 390 mW/g for 238Pu) – and its radiation poses more threat to humans owing to neutron emission, the European Space Agency is considering using americium for its space probes. Another proposed space-related application of americium is a fuel for space ships with nuclear propulsion. It relies on the very high rate of nuclear fission of 242mAm, which can be maintained even in a micrometer-thick foil. Small thickness avoids the problem of self-absorption of emitted radiation. This problem is pertinent to uranium or plutonium rods, in which only surface layers provide alpha-particles. The fission products of 242mAm can either directly propel the spaceship or they can heat a thrusting gas. They can also transfer their energy to a fluid and generate electricity through a magnetohydrodynamic generator. One proposal which utilizes the high nuclear fission rate of 242mAm is a nuclear battery. Its design relies not on the energy emitted by americium alpha particles but on their charge. In this way the americium acts as a self-sustaining cathode. A single 3.2 kg 242mAm charge of such a battery could provide about 140 kW of power over a period of 80 days.
Three main diagnostic manuals used to classify mental health conditions are in use today. The ICD-11 is produced and published by the World Health Organization, includes a section on psychiatric conditions, and is used worldwide. The Diagnostic and Statistical Manual of Mental Disorders, produced and published by the American Psychiatric Association (APA), is primarily focused on mental health conditions and is the main classification tool in the United States. It is currently in its fifth revised edition and is also used worldwide. The Chinese Society of Psychiatry has also produced a diagnostic manual, the Chinese Classification of Mental Disorders. The stated intention of diagnostic manuals is typically to develop replicable and clinically useful categories and criteria, to facilitate consensus and agreed upon standards, whilst being atheoretical as regards etiology. However, the categories are nevertheless based on particular psychiatric theories and data; they are broad and often specified by numerous possible combinations of symptoms, and many of the categories overlap in symptomology or typically occur together. While originally intended only as a guide for experienced clinicians trained in its use, the nomenclature is now widely used by clinicians, administrators and insurance companies in many countries. The DSM has attracted praise for standardizing psychiatric diagnostic categories and criteria. It has also attracted controversy and criticism.
=== Russian aid to Cuba === On 30 March, a Russian oil tanker, the Anatoly Kolodkin, carrying 100,000 tonnes of crude oil, or 730,000 barrels, arrived in Havana. The Russian shipment could be converted into 250,000 barrels of diesel which could cover Cuban energy demands for 12 and a half days. The Guardian argued that the docking of the Russian tanker signals greater American flexibility in the ability of Cuba to purchase oil from abroad. On 27 May, the Universal, a Russian fuel tanker, failed to reach Cuba, turning around off the coast of Brazil. The vessel itself is subject to U.S. sanctions and some speculate that the ship was interceded by American naval authorities.
Sources: en.wikipedia.org
Cardarine is a common name for the investigational compound GW501516. It acts as a PPARδ agonist and is not approved for human use. It is prohibited in sport.
It activates PPARδ, a nuclear receptor that influences gene expression related to lipid and energy metabolism. Animal studies show changes in endurance and lipid levels. Human effects and risks are not well established.
No, cardarine is not a steroid. It belongs to a different chemical class, the PPARδ agonists. It is also not a selective androgen receptor modulator.
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.