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.
Updated 2025-12-30. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 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.
| 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 |
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.
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.
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.
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.
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.
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.
The Biological Stain commission is an independent non-profit company that has been testing dyes since the early 1920s and issuing Certificates of approval for batches of dyes that meet internationally recognized standards. StainsFile Reference for dyes and staining techniques. Vital Staining for Protozoa and Related Temporary Mounting Techniques ~ Howey, 2000 Speaking of Fixation: Part 1 and Part 2 – by M. Halit Umar Photomicrographs of Histology Stains Frequently asked questions in staining exercises at Sridhar Rao P.N's home page
Cyclic GMP-AMP synthases (cGAS, cGAMP synthase), are a class of enzyme. They belongs to the nucleotidyltransferase family, and are part of the cytosolic DNA sensor that activates a type-I interferon response (the cGAS-STING DNA sensing pathway). It binds to microbial DNA as well as self DNA that invades the cytoplasm, and catalyzes cGAMP synthesis. In humans, this enzyme is encoded by the gene CGAS, while in some insects this activity has been found in the proteins encoded by genes cGLR1 or cGLR2.
On 25 February, Gnassingbé was nominated by delegates of the ruling party, the Rally for the Togolese People, as the party's presidential candidate. He was also chosen as head of the party. Shortly afterwards, under mounting domestic and international pressure, Gnassingbé announced that he would step down as president during the interim period and Bonfoh Abass was appointed by the National Assembly to replace him as acting president until the election on 24 April. Bonfoh was considered by some to be a puppet of the military elite and the Gnassingbé family. Gnassingbé competed with the main opposition candidate, Emmanuel Bob-Akitani, a retired engineer of the state-owned mining company and the second most important person in the opposition coalition after Gilchrist Olympio. Olympio could not take part in the election, since the constitution required that any candidate must have lived for at least 12 months in Togo, and Olympio had been in self-imposed exile for fear that he would be murdered by the Eyadema clan like his father. In the election, Gnassingbé received slightly more than 60% of the votes, according to official results. The RPT refused to allow oversight during the counting of the ballots. The EU and the Carter Center deemed the elections to be fraudulent. Mass protests by the coalition of opposition parties led to the killing of over 1,000 citizens by security forces. 40,000 refugees fled to neighboring Benin and Ghana.
Sources: en.wikipedia.org
== Peptide fragmentation == Peptides are protonated in positive-ion mode. The proton initially locates at the N-terminus or a basic residue side chain, but because of the internal solvation, it can move along the backbone breaking at different sites which result in different fragments. The fragmentation rules are well explained by some publications. Three different types of backbone bonds can be broken to form peptide fragments: alkyl carbonyl (CHR-CO), peptide amide bond (CO-NH), and amino alkyl bond (NH-CHR).
== Further reading == Allen, Joe (April 7, 2020). The Package King: A Rank-and-File History of UPS. Chicago, Illinois: Haymarket Books. ISBN 9781642592177. Brewster, Mike and Frederick Dalzell. Driving Change: The UPS Approach to Business (2007) excerpt and text search Thomas L. Friedman, "Insourcing," in The World Is Flat: A Brief History of the Twenty-First Century, New York: Farrar, Straus and Giroux, updated and expanded, 2006, pp. 167–176. Minchin, Timothy J. "Shutting Down 'Big Brown': Reassessing the 1997 UPS Strike and the Fate of American Labor," Labor History, 53 (Nov. 2012), 541–60. Niemann, Greg. Big Brown: The Untold Story of UPS. New York: John Wiley & Sons, 2007.
Raw feeding is the practice of feeding domestic dogs, cats and other animals a diet consisting primarily of uncooked meat, edible bones, and organs. The ingredients used to formulate raw diets can vary. Some pet owners choose to make homemade raw diets to feed their animals but commercial raw food diets are also available. Frozen, or fresh-prepared, meals come in raw or cooked form, some of which is made with ingredients that are inspected, approved, and certified by the USDA for human consumption, but formulated for pets. Part of this growing trend is the commercialization of home-made dog food for pet owners who want the same quality, but do not have the time or expertise to make it themselves. The advantage is forgoing the processing stage that traditional dog food undergoes. This causes less destruction of its nutritional integrity. The practice of feeding raw diets has raised some concerns due to the risk of foodborne illnesses, zoonosis and nutritional imbalances. People who feed their dogs raw food do so for a multitude of reasons, including but not limited to: culture, beliefs surrounding health, nutrition and what is perceived to be more natural for their pets. Feeding raw food can be perceived as allowing the pet to stay in touch with their wild, carnivorous ancestry. The raw food movement has occurred in parallel to the change in human food trends for more natural and organic products.
=== Pest control === Diatomite is of value as an insecticide because of its abrasive and physico-sorptive properties. The fine powder adsorbs lipids from the waxy outer layer of the exoskeletons of many species of insects. This layer acts as a barrier that resists the loss of water vapour from the insect's body. Damaging the layer increases the evaporation of water from their bodies, so that they dehydrate, often fatally. This also works against gastropods and is commonly employed in gardening to defeat slugs. However, since slugs inhabit humid environments, efficacy is low. Diatomaceous earth is sometimes mixed with an attractant or other additives to increase its effectiveness. The shape of diatoms has not been proven to affect their functionality as regarding adsorption of lipids. However, certain applications, such as that for slugs and snails, work best when a particularly shaped diatom is used, suggesting that lipid adsorption is not the only factor involved. For example, in the case of slugs and snails, large, spiny diatoms work best to lacerate the epithelium of the mollusk. Diatom shells will work to some degree on the vast majority of animals that undergo ecdysis in shedding cuticle, such as arthropods or nematodes. It also may have other effects on lophotrochozoans, such as mollusks or annelids. Medical-grade diatomite has been studied for its efficacy as a deworming agent in cattle; in both studies cited the groups being treated with diatomaceous earth did not fare any better than control groups.
Sources: en.wikipedia.org
== Signs and symptoms == The symptoms of ketoacidosis are variable depending on the underlying cause. The most common symptoms include nausea, vomiting, abdominal pain, and weakness. Breath may also develop the smell of acetone as it is a volatile ketone that can be exhaled. Rapid deep breathing, or Kussmaul breathing, may be present to compensate for the metabolic acidosis. Altered mental status is more common in diabetic than alcoholic ketoacidosis.
=== Equilibrium constant === Equilibrium constant of the reaction is also not independent from the other competing equilibria. Competition would include buffer interactions and other pH-dependent reactions depending on the experimental conditions. The competition from species other than the species of interest is included in the competition factor, Q in the following equation:
In a brief review of the 580 model, Consumer Reports described the results of a comparative test of the Verismo 580 against two competitive brands: Because you have to conduct a rinse cycle between each cup, the Verismo wasn't among the most convenient of single-serve machines in our coffeemaker tests. Other machines we've tested have more flexibility in adjusting brew-strength—the Verismo has buttons for coffee, espresso, and latte with no strength variation for any type. And since Starbucks has limited its coffee selection to its own brand, there are only eight varieties so far plus a milk pod for the latte. As of December 31, 2020, Starbucks has discontinued producing their own K-Fee pods for Verismo machines, however, third-party companies continue to produce coffee pods for K-Fee machines, of which the Starbucks Verismo is compatible.
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.