This is a working overview of LC-MS/MS, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-11-27. Anything still debated is marked as such rather than presented as settled.
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
Cardarine is a common name for GW501516, a synthetic compound studied for its effects on lipid and glucose metabolism. It functions as an agonist at peroxisome proliferator-activated receptor delta, or PPARδ, a nuclear receptor that influences gene expression. The molecule is not a steroid, nor is it a selective androgen receptor modulator. It is also known in research and sports literature as GW-501516 and endurobol. Early laboratory work examined its metabolic activity in cell cultures and animal models.
Products sold as cardarine have been found to contain incorrect compounds, variable amounts, or no active ingredient at all. Independent testing is required to verify identity and purity. Common analytical approaches include high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance for structural confirmation. These methods can distinguish GW501516 from related PPAR agonists and from unrelated steroids. For regulators and researchers, such verification is central to interpreting both biological results and adverse event reports.
Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic PPARδ agonist | Not a steroid or a selective androgen receptor modulator. |
| Common synonyms | Cardarine, GW501516, GW-501516, endurobol | Names vary by supplier and literature source. |
| Appearance | White to off-white powder | Consistent with many small-molecule research chemicals. |
| Solubility | Low in water; soluble in DMSO and ethanol | Often prepared in organic solvent for laboratory work. |
| Primary target | PPARδ (NR1C2) | Nuclear receptor involved in lipid and energy metabolism. |
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.
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.
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.
GW501516 acts as an agonist at the peroxisome proliferator-activated receptor delta, a nuclear receptor that regulates gene expression. Activation shifts transcription toward genes involved in fatty acid uptake, oxidation, and energy expenditure. The compound does not bind the androgen receptor and therefore differs from anabolic steroids and SARMs. In rodent models, this metabolic shift has been linked to increased running endurance and reduced fat accumulation. The exact downstream pathways in humans remain incompletely characterized.
Early clinical research explored GW501516 for lipid disorders, obesity, and diabetes. Some short-term human studies reported changes in HDL cholesterol, LDL cholesterol, and triglycerides. The development program was discontinued after rodent studies showed dose-dependent tumor formation in multiple tissues, including liver, bladder, stomach, and skin. These findings raised concerns about long-term cancer risk in humans. Because human exposure data are limited, the clinical significance of the rodent tumors remains uncertain.
GW501516 acts on PPARδ, a nuclear receptor that helps regulate fatty acid oxidation and energy homeostasis. In animal studies, activation of this receptor was associated with increased endurance and changes in lipid metabolism. Human trials examined effects on blood lipids and other metabolic markers, but the compound did not advance to approval. Rodent studies later reported tumors in multiple tissues at doses used in those experiments. Whether those findings translate to human risk remains uncertain, and the clinical relevance of the animal data is still debated.
Regulatory bodies treat GW501516 as a prohibited substance in competitive sport. The World Anti-Doping Agency added it to the prohibited list, and it falls under classes covering metabolic modulators and hormone-related agents. It is not approved by drug regulators for human use, and it is not a lawful dietary supplement. Products sold under the cardarine name may contain unlisted ingredients or different compounds. Because no approved product exists, quality and identity are not guaranteed by pharmaceutical manufacturing standards.
Cardarine is a common name for the investigational chemical GW501516, also written GW-1516. It was developed as a peroxisome proliferator-activated receptor delta agonist for metabolic conditions such as dyslipidemia. Early research focused on lipid handling and energy use in skeletal muscle and other tissues. The compound was never approved as a medicine. In public discussion, it is often grouped with performance-enhancing substances, although its receptor target differs from that of anabolic steroids or selective androgen receptor modulators. Regulatory and health authorities have issued warnings about its use.
Exorphins are exogenous opioid peptides, distinguished from endorphins, or endogenous opioid peptides. Exorphins include opioid food peptides like gluten exorphin and microbial opioid peptides and any other opioid peptide foreign to a host that have metabolic efficacy for that host. Exorphins can be converted from plants and animals but also dairy products and certain vegetables like spinach and soy. Exorphins can be released for many different kinds of proteins and thus can be isolated from various sources such as from plant proteins or from enzymes of the digestive system of animals. The study of exorphins as a bioactive peptide can be a source of discovery for new kinds of food and drugs to treat and prevent diseases associated with the accumulation of exorphins.
From 15 to 20 February, the Battle of Wadi al-Batin took place inside Iraq; this was the first of two attacks by 1 Battalion 5th Cavalry of the 1st Cavalry Division. It was a feint attack, designed to make the Iraqis think that a coalition invasion would take place from the south. The Iraqis fiercely resisted, and the Americans eventually withdrew as planned back into the Wadi al-Batin. Three US soldiers were killed and nine wounded, with one M2 Bradley IFV turret destroyed, but they had taken 40 prisoners and destroyed five tanks, and successfully deceived the Iraqis. This attack led the way for the XVIII Airborne Corps to sweep around behind the 1st Cav and attack Iraqi forces to the west. On 22 February 1991, Iraq agreed to a Soviet-proposed ceasefire agreement. The agreement called for Iraq to withdraw troops to pre-invasion positions within six weeks following a total ceasefire, and called for monitoring of the ceasefire and withdrawal to be overseen by the UN Security Council. The coalition rejected the proposal, but said that retreating Iraqi forces would not be attacked, and gave 24 hours for Iraq to withdraw its forces. On 23 February, fighting resulted in the capture of 500 Iraqi soldiers. On 24 February, British and American armored forces crossed the Iraq–Kuwait border and entered Iraq in large numbers, taking hundreds of prisoners. Iraqi resistance was light, and four Americans were killed.
Native enteropeptidase and the isolated light chain have similar activity toward Gly-(Asp)4-Lys-NHNap, but the secluded light chain has distinctly decreased activity toward trypsinogen . An analogous selective defect in the recognition of trypsinogen can be produced in two-chain enteropeptidase by heating or by acetylation. This behavior implies that the catalytic center and one or more secondary substrate-binding sites are essential for optimal recognition of trypsinogen.
Lactobacillus delbrueckii subsp. lactis is a subspecies of Lactobacillus delbrueckii that is generally used to measure the amount of cobalamin in food. Its growth rate is proportional to the amount of cobalamin in the growth medium. However, lactis has been demonstrated to have the option to utilize pseudocobalamin, which is inactive for humans, as well as "alkali-resistant factors" (deoxyribosides and deoxynucleotides), leading to an overestimation of the amount of cobalamine in food. As such, new methods using HPTLC or LC-MS/MS have also been developed.
=== 1993 === 18 July The Real Jurassic Park, an Equinox Special and also called Jurassic Park Revisited, it looked at whether the film could happen, with American geologist Jim Kirkland of Colorado Mesa University, and Jack Horner, the scientific advisor for the film; Dale Marcellini of Washington Zoo; Ward Wheeler of the American Museum of Natural History and extracting DNA from insects encased in amber, by the PCR method; the work of Raul Cano with Hendrik Poinar at the Department of Entomology at the University of California, Berkeley; Noreen Tuross; Mary Higby Schweitzer and Jack Horner of Montana State University; Robert T. Bakker; geneticist Stephen J. O'Brien of the National Cancer Institute in Virginia; development biologist Peter Anthony Lawrence of the MRC Laboratory of Molecular Biology in Cambridge, with French biologist Jean-Paul Vincent and biochemist Rob Kay; conservation biologist Bill Toone of the California Condor Recovery Program.; Bruce H. Tiffney of University of California, Santa Barbara with Karen Chin; geologist Jim Kirkland. Narrated by Andrew Sachs, produced by Oliver Morse, jointly made with the WGBH Educational Foundation, directed by David Dugan, made by Windfall Films 15 August Bridging the Future, about the science, engineering and technology of bridge-building; the programme examines why bridges sometimes spectacularly fail, and how ever-longer and higher spans are achievable; the programme is introduced by Spike Milligan who recites the poems of William McGonagall, extolling the virtues and sorrows of the legendary Tay Bridge.
Sources: en.wikipedia.org
== Discovery == Studies conducted in the 1970s found that a series of N-formylmethionine-containing oligopeptides, including the most potent and best known member of this series, N-formylmethionine-leucyl-phenylalanine (fMLF or fMet-Leu-Phe), stimulated rabbit and human neutrophils by an apparent receptor-dependent mechanism to migrate in a directional pattern in classical laboratory assays of chemotaxis. Since these oligopeptides were produced by bacteria or synthetic analogs of such products, it was suggested that the N-formyl oligopeptides are important chemotactic factors and their receptors are important chemotactic factor receptors that act respectively as signaling and signal-recognizing elements to initiate inflammation responses in order to defend against bacterial invasion. Further studies defined a receptor for the N-formyl oligopeptides, formyl peptide receptor (FPR), so named based on its ability to bind and become activated by the oligopeptides. Two receptors where thereafter discovered and named FPR1 and FPR2 based on the similarity of their genes' predicted amino acid sequence to that of FPR rather than on any ability to bind or be activated by the formyl oligopeptides.
These studies both reported that all obvious symptoms of scurvy could be completely reversed by supplementation of only 10 mg a day. Treatment of scurvy can be with vitamin C-containing foods or dietary supplements or injection.
== Society and culture == Fibromyalgia causes substantial economic and societal strain due to disability, reduced work hours, informal care, early retirement, and healthcare utilization. According to a 2014 review indirect costs, such as those due to disability and lost productivity, accounted for most of the costs, and the cost to society amounted to "tens of thousands of dollars each year" per patient. A 2022 review of 36 studies found that fibromyalgia causes a significant economic strain on healthcare systems. Annual costs per patient were estimated to be $1,750 to $35,920 in the US, and $1,250 to $8,504 in Europe. People with fibromyalgia can be subjected to significant stigma in society generally, and within the medical system. They may face disbelief in the legitimacy of their pain, moralizing attitudes, and suspicions of malingering, which relate to the invisible nature of the pain and prejudices relating to the historic predominance of women amongst people with the condition. Health professionals may hold negative attitudes towards patients with fibromyalgia, considering them "demanding" or their symptoms to be exaggerated or fake, and they may lack knowledge about the condition, which can also contribute to delays in diagnosis. Many people with fibromyalgia feel that healthcare providers believe they are faking or exaggerating. This stigma can have a considerable impact on the social interactions, trust in healthcare, and mental health of people with fibromyalgia.
== Overview == Permafrost mummies provide crucial insights into the physiology and life histories of Pleistocene organisms, due to how well the preservation process keeps the specimens from decomposing. The constant presence of permafrost is able to preserve the soft tissues of organisms through a process similar to freeze-drying. With such complete preservation of tissues, it is possible to determine numerous things from the such as: DNA, eDNA, evolutionary history, gut contents, and trophic dynamics. Studies have even shown that the process is so complete there is evidence of nucleic activity. Some of these specimens are on display at the Kingdom of the Permafrost museum near Yakutsk. (E) - denote an extinct species or subspecies
==== Blood pressure lowering ==== Many international guidelines recommend blood pressure treatment targets that are lower than 140/90 mmHg for people with diabetes. However, there is only limited evidence regarding what the lower targets should be. A 2016 systematic review found potential harm to treating to targets lower than 140 mmHg, and a subsequent review in 2019 found no evidence of additional benefit from blood pressure lowering to between 130 and 140 mmHg, although there was an increased risk of adverse events. 2023 European Society of Cardiology guidelines recommend systolic blood pressure lowering to 130 mmHg in most people with diabetes. In people with diabetes and hypertension and either albuminuria or chronic kidney disease, an inhibitor of the renin-angiotensin system (such as an ACE inhibitor or angiotensin receptor blocker) to reduce the risks of progression of kidney disease and present cardiovascular events. There is some evidence that angiotensin converting enzyme inhibitors (ACEIs) are superior to other inhibitors of the renin-angiotensin system such as angiotensin receptor blockers (ARBs), or aliskiren in preventing cardiovascular disease. Although a 2016 review found similar effects of ACEIs and ARBs on major cardiovascular and renal outcomes. There is no evidence that combining ACEIs and ARBs provides additional benefits.
Sources: en.wikipedia.org
=== Long-term === Finasteride may cause persistent adverse sexual, neurological, and physical effects in a subset of men. A 2019 systematic review surveyed the literature on the reversibility of finasteride's side effects. It identified three studies that demonstrated full reversibility of side effects and eleven that described patients with irreversible adverse events. A separate 2017 retrospective review of nearly 12,000 patients found 1.4% developed persistent (lasting at least 90 days after stopping Finasteride) ED, with this dropping to 0.8% for 16-42 year olds.
== Diagnosis == There are some laboratory tests that may aid in the diagnosis of GSD-V. A muscle biopsy will note the absence of myophosphorylase in muscle fibers. In some cases, abnormal glycogen accumulation stained by periodic acid-Schiff can be seen with microscopy. Genetic sequencing of the PYGM gene (which codes for the muscle isoform of glycogen phosphorylase) may be done to determine the presence of gene mutations, determining if McArdle's is present. This type of testing is considerably less invasive than a muscle biopsy. The physician can also perform an ischemic forearm exercise test as described below (see History). Some findings suggest a nonischemic test could be performed with similar results. The nonischemic version of this test would involve not cutting off the blood flow to the exercising arm. Findings consistent with McArdle's disease would include a failure of lactate to rise in venous blood and exaggerated ammonia levels. These findings would indicate a severe muscle glycolytic block. Serum lactate may fail to rise in part because of increased uptake via the monocarboxylate transporter (MCT1), which is upregulated in skeletal muscle in McArdle disease. Lactate may be used as a fuel source once converted to pyruvate. Ammonia levels may rise given ammonia is a by-product of AMP deaminase which follows after the production of AMP by adenylate kinase, an alternative pathway for ATP production.
== Membership == In 1975, chairman Frank Zeidler claimed that SPUSA had around 500 members nationwide. SPUSA saw growth during the late 1970s and early to mid-1980s, expanding from around 600 members to around 1,700 members. In 2008, WMNF claimed that SPUSA had around 3,000 members. However, in 2010, CommonDreams wrote that SPUSA had only 1,000 members, and party members described that as an increase in membership. In May 2011, The New York Times stated that SPUSA had "about 1,000 members nationally". In February 2012, The Root stated that SPUSA had "around 1,500" members.
=== LTG4 === There has also been postulated the existence of LTG4, a metabolite of LTE4 in which the cysteinyl moiety has been oxidized to an alpha-keto-acid (i.e.—the cysteine has been replaced by a pyruvate). Very little is known about this putative leukotriene.
Sources: en.wikipedia.org
Cardarine is a common name for GW501516, a synthetic PPARδ agonist. It is not a steroid or a selective androgen receptor modulator. It was developed and studied as a research compound for metabolic pathways.
It binds to and activates PPARδ, a nuclear receptor that regulates genes related to fatty acid oxidation and energy use. This activation alters transcription in tissues such as skeletal muscle and liver. The full range of downstream effects in humans is not fully established.
No, cardarine is not known to occur naturally in plants, animals, or humans. It is a synthetic molecule produced for laboratory research. Products labeled as cardarine should therefore be treated as manufactured chemicals with variable purity.
Legal status varies by country, but cardarine is not approved as a medicine in major jurisdictions. It is often sold as a research chemical, a category that may not be lawful for human use. Buyers should check local laws and product labels carefully.