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 2025-09-30. Numbers and descriptions here follow the published literature rather than marketing material.
Published studies have examined GW501516 in animal models of obesity, insulin resistance, and exercise endurance. Early human trials reportedly ended, and development was discontinued after preclinical findings raised concerns about cancer in some rodent studies. Regulatory agencies have not approved cardarine for any medical use. Its availability through non-pharmaceutical channels raises questions about identity, purity, and legal status that are separate from its laboratory pharmacology. Those questions are often addressed through analytical testing rather than assumptions about product labels.
Cardarine is a common name for GW501516, also GW-1516, a synthetic compound developed as a peroxisome proliferator-activated receptor delta (PPARδ) agonist. It belongs to a class of agents that modulate gene transcription related to lipid and energy metabolism. The compound was studied in preclinical and early clinical research for metabolic and cardiovascular conditions, but it did not progress to approved therapeutic use. Its name appears in fitness and sports contexts despite not being approved as a drug.
Sporting authorities added GW501516 to prohibited lists after it appeared in athlete samples and online markets. The World Anti-Doping Agency classifies it as a hormone and metabolic modulator, and its use can lead to an anti-doping rule violation. Some early laboratory work suggested effects on fatty acid oxidation and endurance-related metabolism in animals, but those findings do not establish safe or effective use in people. Reports of adverse events in humans are scarce and often anecdotal, which complicates risk assessment.
Legal status varies by country. In some places, cardarine is controlled under medicines or psychoactive substances laws; in others, it may be sold with minimal oversight as a research chemical. Customs agencies have intercepted shipments, and several national health agencies have issued warnings about products marketed for bodybuilding or performance enhancement. The lack of a standardized pharmaceutical supply means identity, purity, and contamination levels can differ widely between samples. These factors make cardarine a regulatory and public health concern rather than a conventional prescription drug.
| Property | Value | Notes |
|---|---|---|
| Chemical class | PPARδ agonist | Not an anabolic steroid. |
| Common synonyms | GW501516, GW-1516 | Cardarine is an informal name. |
| Appearance | White to off-white powder | Typical for research-grade solid. |
| Solubility class | Poorly soluble in water; soluble in some organic solvents | Such as DMSO or ethanol in laboratory settings. |
| Typical storage temperature | Cool, dry, protected from light | Specific conditions vary by supplier and form. |
Cardarine is frequently described as a fat-burning or endurance-enhancing supplement, but these claims exceed the available evidence. The compound is not a hormone, steroid, or selective androgen receptor modulator. Research articles discuss it as a tool compound for studying PPARδ biology, while anti-doping literature focuses on its abuse and detection. Quality of unapproved products is uncertain, and independent analyses have found impurities or incorrect labeling. Open questions include whether human cancer risk resembles that seen in rodents and how often non-athletes use the substance.
Cardarine has no approved therapeutic indication and is not marketed as a medicine. The World Anti-Doping Agency lists GW501516 as a prohibited substance at all times, covering both in-competition and out-of-competition periods. National laws vary: some countries treat it as an unapproved drug subject to import controls, while others have specific restrictions on sale for human consumption. It is often sold as a research chemical, a label that does not imply safety or legality. Enforcement actions have targeted online vendors and shipments.
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.
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.
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.
In laboratory settings, cardarine is studied as a tool compound for probing PPARδ biology. Published experiments often use cell cultures, rodent models, or isolated tissues. Some investigations focus on metabolic effects, while others assess potential risks such as carcinogenicity observed in long-term animal studies. Because human trials are sparse, most knowledge comes from preclinical work and adverse event reports. Scientific literature frequently notes the gap between animal findings and human outcomes. The compound is not a dietary supplement and is not intended for human consumption.
Cardarine is a common name for GW501516, a synthetic compound developed in the 1990s through research collaborations involving GlaxoSmithKline. It belongs to a class of molecules known as peroxisome proliferator-activated receptor delta agonists. Early studies explored its effects on lipid metabolism and energy expenditure in animal models. The compound was never approved as a human medicine, and clinical development was discontinued. In the years since, it has appeared in fitness and bodybuilding communities as a performance-enhancing substance. Regulatory agencies classify it as an unapproved drug.
PPARδ is a nuclear receptor that regulates gene expression related to fatty acid oxidation, glucose homeostasis, and mitochondrial function. GW501516 binds to this receptor with high affinity and activates downstream signaling in skeletal muscle and other tissues. Animal studies reported increased endurance and altered fuel preference, but human data remain limited and inconsistent. The precise relationship between receptor activation and observed physiological changes is still an area of active investigation. Researchers have also examined whether the compound affects inflammation or cell proliferation. No approved therapeutic indication exists for cardarine.
Glutathione synthetase deficiency (GSD) is a rare autosomal recessive metabolic disorder that prevents the production of glutathione. Glutathione helps prevent damage to cells by neutralizing harmful molecules generated during energy production. Glutathione also plays a role in processing medications and cancer-causing compounds (carcinogens), and building DNA, proteins, and other important cellular components.
== Rate of usage == In 2013, 77% of Nigerian women, 52% of Senegalese women, and 25% of Malian women were using lightening products. In 2020, Der Spiegel reported that in Ghana, "When You Are Light-Skinned, You Earn More", and that "[s]ome pregnant women take tablets in the hopes that it will lead their child to be born with fair skin. Some apply bleaching lotion [...] to their babies, in the hopes that it will improve their child's chances." Skin whiteners typically range widely in pricing. Olumide attributes this to the desire to portray whitening as financially accessible to all. These products are marketed to both men and women, though studies indicate that, in Africa, women use skin bleachers more than men do. A study by Lester Davids and his colleagues indicated that nations in Africa present high rates of usage for skin bleachers. Though many products have been banned due to toxic chemical compositions, Davids found that regulating policies are often not strictly enforced. In India, the sales of skin lightening creams in 2012 totaled around 258 tons, and in 2013 sales were about US$300 million. By 2018, the industry for lightening cosmetics in India had achieved a net worth of nearly $180 million and an annual growth rate of 15%. As of 2013, the global market for skin lighteners was projected to reach $19.8 billion by 2018, based on sales growth primarily in Africa, Asia, and the Middle East. In the United Kingdom, many skin whiteners are illegal due to possible adverse effects. Such products are frequently still sold even after shops have been prosecuted.
Pakistan Horticulture Development & Export Board (PHDEC), an autonomous body under the administrative control of the Ministry of Commerce has been mandated with the development of the horticulture industry of Pakistan with a focus on exports. Its functions include the provision of improved marketing infrastructure like the establishment of agro-processing zones, cold chain system, processing plants for value-added products. The implementation arrangements are preferably under the public-private partnership (PPP) modality with a clear exit strategy. PHDEC envisions the vitalization of a dynamic and market-driven horticulture sector, which is resilient, sustainable and responsive to meet the challenges of globalization.
The colonial government in South West Africa (present-day Namibia), from 1904 to 1908, carried out the annihilation of the local Herero and Nama peoples as punishment for an uprising; this was the 20th century's first genocide. The assassination of Austria's crown prince on 28 June 1914 provided the pretext for Austria-Hungary to attack Serbia and trigger World War I. After four years of warfare, in which approximately two million German soldiers were killed, a general armistice ended the fighting. In the German Revolution (November 1918), Wilhelm II and the ruling princes abdicated their positions.
Sources: en.wikipedia.org
== Further reading == Fruton, Joseph S. Proteins, Enzymes, Genes: The Interplay of Chemistry and Biology. Yale University Press: New Haven, 1999. ISBN 0-300-07608-8 Kohler, Robert. From Medical Chemistry to Biochemistry: The Making of a Biomedical Discipline. Cambridge University Press, 1982.
=== Abnormal heart rhythm === In August 2011, the FDA announced, "Citalopram causes dose-dependent QT interval prolongation. Citalopram should no longer be prescribed at doses greater than 40 mg per day". A further clarification, issued in March 2012, restricted the maximum dose to 20 mg for subgroups of patients, including those older than 60 years and those taking an inhibitor of cytochrome P450 2C19.7.
In October 2010, Biden said Obama had asked him to remain as his running mate for the 2012 presidential election, but with Obama's popularity declining, White House Chief of Staff William M. Daley conducted some secret polling and focus group research in late 2011 on the idea of replacing Biden with Hillary Clinton. The notion was dropped when the results showed no appreciable improvement, and White House officials later said Obama himself never entertained the idea. Biden's May 2012 statement that he was "absolutely comfortable" with same-sex marriage gained considerable public attention in comparison to Obama's position, which had been described as "evolving". Biden made his statement without administration consent, and Obama and his aides were irked, since Obama had planned to shift position in the build-up to the party convention. Gay rights advocates seized upon Biden's statement, and within days, Obama announced that he too supported same-sex marriage, an action in part forced by Biden's remarks. Biden had a heavy schedule of appearances in swing states as the reelection campaign began in earnest in spring 2012. An August 2012 remark before a mixed-race audience that Republican proposals to relax Wall Street regulations would "put y'all back in chains" again drew attention to Biden's propensity for colorful remarks.
=== As a soaking agent === Aqueous sulfur dioxide solution is used in corn wet-milling, in the steeping stage of the process. The corn kernels are soaked in this solution in large tanks containing lactic acid and sulfur dioxide at around 53˚C (127˚F) temperature for nearly 40 hours. This is done to soften the kernel so that the oil in the germ will not contaminate other products and is easy to separate.
== Pathophysiology == Episcleritis is caused by inflammation due to the activation of immune cells, including lymphocytes and macrophages. In most cases, the cause of episcleritis is never determined (idiopathic). An identifiable cause is discovered in about one third of cases. Several diseases are associated with episcleritis, including systemic vasculitis (polyarteritis nodosa, granulomatosis with polyangiitis, Behçet's disease), connective tissue diseases (rheumatoid arthritis, relapsing polychondritis, systemic lupus erythematosus), psoriatic arthritis, ankylosing spondylitis, Cogan syndrome, rosacea, gout, atopy, Crohn's disease, and ulcerative colitis. 59 percent of patients with relapsing polychondritis have either episcleritis or scleritis. Rarely, episcleritis may be caused by scleritis. Very rarely, episcleritis is associated with infections, including Lyme disease, tuberculosis, syphilis, and herpes zoster. The redness in the eye associated with episcleritis is due to engorgement of the large episcleral blood vessels, which run in a radial direction from the limbus. Typically, there is no uveitis, or thickening of the sclera.
Sources: en.wikipedia.org
Among the earliest reports of MOF-based catalysis was the cyanosilylation of aldehydes by a 2D MOF (layered square grids) of formula Cd(4,4′-bpy)2(NO3)2. This investigation centered mainly on size- and shape-selective clathration. A second set of examples was based on a two-dimensional, square-grid MOF containing single Pd(II) ions as nodes and 2-hydroxypyrimidinolates as struts. Despite initial coordinative saturation, the palladium centers in this MOF catalyze alcohol oxidation, olefin hydrogenation, and Suzuki C–C coupling. At a minimum, these reactions necessarily entail redox oscillations of the metal nodes between Pd(II) and Pd(0) intermediates accompanying by drastic changes in coordination number, which would certainly lead to destabilization and potential destruction of the original framework if all the Pd centers are catalytically active. The observation of substrate shape- and size-selectivity implies that the catalytic reactions are heterogeneous and are indeed occurring within the MOF. Nevertheless, at least for hydrogenation, it is difficult to rule out the possibility that catalysis is occurring at the surface of MOF-encapsulated palladium clusters/nanoparticles (i.e., partial decomposition sites) or defect sites, rather than at transiently labile, but otherwise intact, single-atom MOF nodes. "Opportunistic" MOF-based catalysis has been described for the cubic compound, MOF-5.
A third, only marginally related concept was proposed in 1923 by Gilbert N. Lewis, which includes reactions with acid–base characteristics that do not involve a proton transfer. A Lewis acid is a species that accepts a pair of electrons from another species; in other words, it is an electron pair acceptor. Brønsted acid–base reactions are proton transfer reactions while Lewis acid–base reactions are electron pair transfers. Many Lewis acids are not Brønsted–Lowry acids. Contrast how the following reactions are described in terms of acid–base chemistry:
One Iraqi soldier, who had fought in the Iran–Iraq War, remarked that his brigade "had sustained more punishment from allied airpower in 30 minutes at Khafji than in eight years of fighting against Iran."
=== Biologically-derived units === The extremely strong complexation between avidin and biotin is instrumental in blood clotting, and has been used as the recognition motif to construct synthetic systems. The binding of enzymes with their cofactors has been used as a route to produce modified enzymes, electrically contacted enzymes, and even photoswitchable enzymes. DNA has been used both as a structural and as a functional unit in synthetic supramolecular systems.
==== Porotic hyperostosis/cribra orbitalia ==== It was long assumed that iron deficiency anemia has marked effects on the flat bones of the cranium of infants and young children. That as the body attempts to compensate for low iron levels by increasing red blood cell production in the young, sieve-like lesions develop in the cranial vaults (termed porotic hyperostosis) and/or the orbits (termed cribra orbitalia). This bone is spongy and soft. It is however, unlikely that iron deficiency anemia is a cause of either porotic hyperostosis or cribra orbitalia. These are more likely the result of vascular activity in these areas and are unlikely to be pathological. The development of cribra orbitalia and porotic hyperostosis could also be attributed to other causes besides a dietary iron deficiency, such as nutrients lost to intestinal parasites. However, dietary deficiencies are the most probable cause. Anemia incidence may be a result of inequalities within society, and/or indicative of different work patterns and activities among different groups within society.
Sources: en.wikipedia.org
Cardarine is commonly known as GW501516 or GW-1516. These names refer to the same synthetic compound. It is not a brand-name approved medicine.
No, cardarine is not a steroid. It is classified as a PPARδ agonist. Its structure and receptor target differ from anabolic steroids.
No regulatory agency has approved cardarine as a medicine. It was investigated in early research but development was discontinued. It is not available as a prescription drug.
No. Major drug regulators have not approved GW501516 for treating any medical condition. Products sold as cardarine are typically unapproved research chemicals or supplements, so their contents and safety are not assured.