A practical reference on Laboratory compound: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-11-23 and is reviewed periodically as new material appears.
In the fitness and bodybuilding literature, cardarine is frequently discussed as an endurance agent or fat-loss compound, although such claims are not supported by robust clinical evidence. Online descriptions often mix animal data, user anecdotes, and marketing language. Researchers who study PPARδ agonists distinguish between receptor activation in controlled experiments and unsupervised use of unverified products. The latter introduces unknown purity, dose, and interactions, making reported experiences difficult to interpret scientifically.
GW501516 acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in transcription of genes related to lipid handling and energy use. Activation of PPARδ can shift skeletal muscle toward greater fatty acid oxidation in animal models, which is one reason it drew interest for metabolic disease and exercise research. The exact downstream effects depend on tissue, species, dose, and duration. Human data are sparse, so many proposed benefits remain hypotheses rather than established clinical outcomes.
Laboratory studies have examined GW501516 in cell cultures and rodents for conditions such as dyslipidemia, insulin resistance, and obesity. Some trials in humans were initiated, but development was discontinued after preclinical findings raised concerns about cancer in certain models. Those findings do not prove that the compound causes cancer in people, but they contributed to regulatory caution. Later reviews often describe the evidence as preliminary and insufficient for assessing long-term safety.
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.
| Property | Value | Notes |
|---|---|---|
| Solubility | Soluble in dimethyl sulfoxide and some organic solvents; practically insoluble in water | Solvent choice affects laboratory handling |
| Typical storage | -20 °C, desiccated, protected from light | Common condition for research samples |
| Analytical method | Liquid chromatography–tandem mass spectrometry (LC-MS/MS) | Used for identification and quantification in biological or product samples |
| Common synonyms | GW501516, GW-501516, GSK-516, Endurobol | Names found in research and anti-doping literature |
| Regulatory status | Unapproved therapeutic; prohibited in competitive sport | Status can vary by country and context |
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.
Activation of PPARδ changes transcription of genes involved in fatty acid transport, mitochondrial function, and skeletal muscle fuel preference. In rodent studies, pharmacological PPARδ activation was associated with increased endurance and altered body composition. These findings generated interest in performance enhancement, but species differences and study designs limit direct extrapolation to humans. Small human trials were conducted in the 2000s and later discontinued. The extent to which cardarine produces similar metabolic or performance effects in people remains an open question.
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.
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.
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.
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.
Larry Hama took over Wolverine's solo series in 1990, and exerted a major influence on how Wolverine was depicted throughout the X-Men family of publications during his run. Hama commented that he "considered the Chris Claremont, Frank Miller, and Barry Windsor-Smith [Wolverine] stories to be canon" and "pretty much ignored everything else." From 1990 to 1992, the series was usually illustrated by Marc Silvestri, who contributed to the character's rising popularity; his work on Wolverine also established him as a star artist in the industry. In issues #48-50 (November 1991-January 1992), Hama delved into Wolverine's mysterious past in the Weapon X program, which was often highly convoluted and unreliable due to the false memories implanted by the program's designers. In 1992, he revisited the Japanese setting and characters of Claremont's and Miller's earlier limited series, ending the story with the poisoning of Mariko Yashida, Logan's lover, and her mercy killing at the hands of Wolverine. During the Fatal Attractions storyline, in X-Men #25 (October 1993), the adamantium in Wolverine's body is ripped out by Magneto, using his magnetic abilities. Writers Fabian Nicieza and Scott Lobdell were inspired by a suggestion of another Marvel writer, Peter David. The story arc reveals that Wolverine has natural bone claws, in contrast to previously established narrative continuity that his claws were entirely bionic. Wolverine himself is confused by this realization, and his healing factor is also greatly weakened by recovery from this extraordinary injury.
=== BK channels === The second type of potassium channel that tertiapin blocks is the calcium activated large conductance potassium channel (BK). The block of BK cells is voltage-, concentration- and use-dependent, meaning the blockage changes with different stimulation voltages and frequencies, different concentrations and with the duration of application of tertiapin. The IC50 for BK channels is 5.8 nM. The BK channels have a role in the onset of the afterhyperpolarization, thereby shortening the action potential and enhancing the speed of repolarization. Total blockage by tertiapin prolongs the duration of the action potential and inhibits the afterhyperpolarization amplitude, leading to an increase of the neuronal excitability. Tertiapin inhibits the BK channels only after a minimal stimulation of 15 minutes, in contrast with less than a minute for the GIRK channels. For this reason it is thought that the mode of action of tertiapin is different for each channel type.
While ethical approaches to the excavation and analysis of physical human remains have received considerable attention, professional and academic dialogue regarding how to appropriately record, share, and display human remains in the digital realm is less developed. While digital technologies for recording and analysing human remains are increasingly accessible, justification for such recording and analysis is essential e.g. 3D scanning performed simply because it is possible is inappropriate and disrespectful to the deceased.
=== Medicaid overbilling === A fraud investigation by the United States Department of Justice began in 2000 when allegations were brought in two separate lawsuits filed by whistleblowers under the False Claims Act. They alleged that Merck failed to pay proper rebates to Medicaid and other health care programs and paid illegal remuneration to health care providers. On February 7, 2008, Merck agreed to pay more than $650 million to settle charges that it routinely overbilled Medicaid for its most popular medicines. The settlement was one of the largest pharmaceutical settlements in history. The federal government received more than $360 million, plus 49 states and Washington, DC, received over $290 million. One whistleblower received a $68 million reward. Merck made the settlement without an admission of liability or wrongdoing.
Sources: en.wikipedia.org
=== Reversal potential === Even if both K+ and Na+ ions have the same charge, they can still have very different equilibrium potentials for both outside and/or inside concentrations. The sodium-potassium pump moves toward a nonequilibrium state with the relative concentrations of Na+ and K+ for both inside and outside of cell. For instance, the concentration of K+ in cytosol is 100-140 mM, whereas the concentration of Na+ is 5-15 mM. On the other hand, in extracellular space, the usual concentration range of K+ is about 3.5-5 mM, whereas the concentration of Na+ is about 135-145 mM.
Money serves three purposes: a store of value, a medium of exchange, and a unit of account. According to The Economist in 2014, bitcoin functions best as a medium of exchange. In 2015, The Economist noted that bitcoins had three qualities useful in a currency: they are "hard to earn, limited in supply and easy to verify". However, a 2018 assessment by The Economist stated that cryptocurrencies met none of these three criteria. Per some researchers, as of 2015, bitcoin functions more as a payment system than as a currency. In 2014, economist Robert J. Shiller wrote that bitcoin has potential as a unit of account for measuring the relative value of goods, as with Chile's Unidad de Fomento, but that "Bitcoin in its present form... doesn't really solve any sensible economic problem". In 2017, François Velde, senior economist at the Chicago Fed, described bitcoin as "unlikely by itself to replace monies in well-functioning monetary systems." The legal status of bitcoin varies substantially from one jurisdiction to another. Because of its decentralized nature and its global presence, regulating bitcoin is difficult. However, the use of bitcoin can be criminalized, and shutting down exchanges and the peer-to-peer economy in a given country would constitute a de facto ban. The use of bitcoin by criminals has attracted the attention of financial regulators, legislative bodies, and law enforcement. Nobel-prize winning economist Joseph Stiglitz says that bitcoin's anonymity encourages money laundering and other crimes. This is the main justification behind bitcoin bans.
Leela Kapila, Consultant Paediatric Surgeon, University Hospital, Nottingham. For services to Medicine. Fergal Patrick Keane, BBC Foreign Correspondent. For services to Television Journalism. John Kelly. For services to Agriculture and to Banking. John Charles King, Chief Executive, Security Facilities Executive, Cabinet Office (Office of Public Service). John Kirkham, lately Grade 6, Ministry of Agriculture, Fisheries and Food. Glen Kirton. For services to Association Football, particularly Euro 96. Alice Elizabeth Audrey Lamb. For services to Education. Penelope Lambert. For services to the Board of Visitors Her Majesty's Prison Whitemoor. Michael John Leech, Principal, Stevenson College, Edinburgh. For services to Education. Gilberte-Marie Brunsdon-Lenaerts. For services to Anglo-Belgian Relations. Ann Molyneux Lewis, lately President, Royal Pharmaceutical Society of Great Britain. For services to the Pharmacy Profession. Kenneth Lewis, Chairman, Horizon NHS Trust. For services to Health Care. Timothy Lewis. For services to the Police. Ian Stanley Cash Linney. For services to the community in Nottinghamshire. James Logan. For services to Aviation. Angus Victor Peck MacKay, Physician Superintendent, Argyll and Bute Hospital. For services to Medicine. William Alexander Lee MacKay, Vice Chairman, Management and Human Resources Committee, Association of District Councils. For services to Local Government. Lieutenant Colonel John Pierce Margarson, . For services to Soldiers' Sailors' and Airmens' Families Association in Clwyd.
Sources: en.wikipedia.org
It binds and activates PPARδ, a nuclear receptor that influences gene expression related to fatty acid metabolism and energy balance. This mechanism has been studied mainly in animals and cell models, not established as a safe human therapy.
No. It is not an anabolic-androgenic steroid; it is a synthetic PPARδ agonist. Because it is banned in sport, it is sometimes grouped with doping agents even though its chemical class differs from steroids.
Human data are limited and development was discontinued, so major effects and long-term risks are not well characterized. Some early studies examined metabolic markers, but they do not provide a basis for unsupervised use.
Anti-doping laboratories typically use LC-MS/MS to detect GW501516 and its metabolites in urine. The method is sensitive and can identify the compound at low concentrations. Detection depends on sample timing, metabolism, and the specific assay.