carcinogenicity raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-03-30 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Common for reference-grade material. |
| Solubility | Low in water | Dissolves in DMSO and some organic solvents. |
| Typical storage | -20 °C, desiccated | Protect from light and moisture. |
| Analytical method | LC-MS/MS | Used for trace detection in biological matrices. |
| Purity assessment | HPLC with UV detection | Often combined with NMR and mass spectrometry. |
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.
A persistent misconception is that cardarine is a fat-burning drug or a safe alternative to anabolic steroids. No approved therapeutic product exists, and human safety data are limited. The tumor findings in rodents remain a central concern in scientific reviews. Products sold online may contain inaccurate labels, impurities, or different compounds entirely, which complicates any assessment of effects. Independent testing of such products has reported frequent mislabeling. For these reasons, discussions in the literature emphasize risks and unknowns rather than benefits.
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.
== History == Pharmaceutical company Johnson & Johnson's Ortho Research Laboratory wrote that case histories of his therapy, "were quite remarkable and your concepts most intriguing" and ICN Pharmaceuticals replied, "The results you have obtained with this drug in the treatment of gangrene have been most spectacular", but DeMarco was never able to commercialize the therapy beyond his own medical practice. Swiss pharmaceutical company Debiopharm S.A. replied, "Drug induced cell regeneration appears to be a revolutionary new form of treatment which is bound to be perceived as highly controversial by several regulatory agencies. We are not in a position to take the considerable time and risk involved in convincing the bureaucrats." Thus although intrigued, the pharmaceutical companies never showed a serious interest in developing his product. Regenerative medicine was a new field at the time and DeMarco likened the companies' antipathy of his discovery to the history of penicillin; although discovered in 1928, penicillin was not mass-produced until 1941 when production became a top priority World War II project to reduce the infection casualty rate. DeMarco's clinical use of a drug not approved by the U.S. Food and Drug Administration came to the attention of regulators in both New Jersey and Pennsylvania, leading to the suspension of his license to practice and the seizure of his supply of procaine hydrochloride, which investigators later found to be contaminated and mislabeled. The New Jersey Department of Health traced 64 cases of infectious hepatitis to Dr. DeMarco.
==== Iodine crystals ==== A potentially lower cost alternative to using iodine-based water purification tablets is the use of iodine crystals, although there are serious risks of acute iodine toxicity if preparation and dilution are not measured with some accuracy. This method may not be adequate in killing Giardia cysts in cold water. An advantage of using iodine crystals is that only a small amount of iodine is dissolved from the iodine crystals at each use, giving this method of treating water a capability for treating very large volumes of water. Unlike tetraglycine hydroperiodide tablets, iodine crystals have an unlimited shelf life as long as they are not exposed to air for long periods of time or are kept under water. Iodine crystals will sublimate if exposed to air for long periods of time. The large quantity of water that can be purified with iodine crystals at low cost makes this technique especially cost effective for point of use or emergency water purification methods intended for use longer than the shelf life of tetraglycine hydroperiodide.
=== Allergic asthma reactions === Asthma may be atopic (i.e., symptoms triggered by allergens) or non-atopic (i.e., symptoms triggered by non-allergenic factors such as cold air). The studies reported here relate to allergen-induced asthma. Mice fed a diet that lowers their SC-FAs levels and then given intranasal injections of dust mite extract developed dust mite allergy asthma reactions to the injections. Their respiratory tract airways had increased numbers of eosinophils and goblet cells as well as excessive levels of mucus; their lung tissue levels of interleukin-4, interleukin-5, interleukin-13, and interleukin-17A and serum immunoglobulin E levels were elevated; and their airway resistance response to a bronchial challenge test was high. In contrast, mice fed a diet that increased their SC-FAs levels developed less of these responses to the extract. Furthermore, mice on the SC-FA lowering diet that were given propionic acid also had far less of these responses to the mite extract. And, Ffar3 (but not Ffar2) gene knockout mice on the low SF-FA diet did not show rises in their lung airway eosinophil levels in response to the mite extract (this was the only parameter of asthma reported in the knockout studies). These finding implicate propionic acid and FFAR3 in the suppression of asthma allergic reactions to mite extract in mice. A second study investigated the effects that an inulin-rich diet (which raises bodily SC-FA levels) feed to rats had on their offsprings' development of asthma. Pregnant rats were feed a normal or inulin-rich diet for 1 week.
The biomolecular structure forms the 3D configuration of the protein. Understanding the protein's structure aids in the identification of the protein's interactions and function. It used to be that the 3D structure of proteins could only be determined using X-ray crystallography and NMR spectroscopy. As of 2017, Cryo-electron microscopy is a leading technique, solving difficulties with crystallization (in X-ray crystallography) and conformational ambiguity (in NMR); resolution was 2.2Å as of 2015. Now, through bioinformatics, there are computer programs that can in some cases predict and model the structure of proteins. These programs use the chemical properties of amino acids and structural properties of known proteins to predict the 3D model of sample proteins. This also allows scientists to model protein interactions on a larger scale. In addition, biomedical engineers are developing methods to factor in the flexibility of protein structures to make comparisons and predictions.
However, the details of how serpin polymers cause cell death remains to be fully understood. Physiological serpin polymers are thought to form via domain swapping events, where a segment of one serpin protein inserts into another. Domain-swaps occur when mutations or environmental factors interfere with the final stages of serpin folding to the native state, causing high-energy intermediates to misfold. Both dimer and trimer domain-swap structures have been solved. In the dimer (of antithrombin), the RCL and part of the A-sheet incorporates into the A-sheet of another serpin molecule. The domain-swapped trimer (of antitrypsin) forms via the exchange of an entirely different region of the structure, the B-sheet (with each molecule's RCL inserted into its own A-sheet). It has also been proposed that serpins may form domain-swaps by inserting the RCL of one protein into the A-sheet of another (A-sheet polymerisation). These domain-swapped dimer and trimer structures are thought to be the building blocks of the disease-causing polymer aggregates, but the exact mechanism is still unclear.
Sources: en.wikipedia.org
== Impact of the altered protein binding == Only the unbound fraction of the drug undergoes metabolism in the liver and other tissues. As the drug dissociates from the protein, more and more drug undergoes metabolism. Changes in the levels of free drug change the volume of distribution because free drug may distribute into the tissues leading to a decrease in plasma concentration profile. For the drugs which rapidly undergo metabolism, clearance is dependent on the hepatic blood flow. For drugs which slowly undergo metabolism, changes in the unbound fraction of the drug directly change the clearance of the drug. The most commonly used methods for measuring drug concentration levels in the plasma measure bound as well as unbound fractions of the drug. The fraction unbound can be altered by a number of variables, such as the concentration of drug in the body, the amount and quality of plasma protein, and other drugs that bind to plasma proteins. Higher drug concentrations would lead to a higher fraction unbound, because the plasma protein would be saturated with drug and any excess drug would be unbound. If the amount of plasma protein is decreased (such as in catabolism, malnutrition, liver disease, renal disease), there would also be a higher fraction unbound. Additionally, the quality of the plasma protein may affect how many drug-binding sites there are on the protein.
=== Cell-free systems === E. coli cell lysate containing the cellular components required for transcription and translation are used in this in vitro method of protein production. The advantage of such system is that protein may be produced much faster than those produced in vivo since it does not require time to culture the cells, but it is also more expensive. Vectors used for E. coli expression can be used in this system although specifically designed vectors for this system are also available. Eukaryotic cell extracts may also be used in other cell-free systems, for example, the wheat germ cell-free expression systems. Mammalian cell-free systems have also been produced.
The initial product from the hydrolysis reaction is de-watered and further processed by dry cracking at 500 °C. The "SlurryCarb" process operated by EnerTech uses similar technology to decarboxylate wet solid biowaste, which can then be physically dewatered and used as a solid fuel called E-Fuel. The plant at Rialto is said to be able to process 683 tons of waste per day.
It combines peptide-coated iron oxide attached to "reporter chemicals". When a peptide binds to a thrombin molecule, the report is released and appears in the urine where it can be detected. Human testing has not been conducted.
==== Cibacron Blue F3GA ==== Cibacron Blue F3GA, Procion Blue HB, or Reactive blue 2 is a purinergic receptor antagonist, such as P2Y purinoceptor, and also an ATP receptor channels antagonist. It has a formula of C29H20ClN7O11S3 and a molecular weight of 774.2 g/mol. Cibacron blue is soluble in water and DMSO, however insoluble in ethanol. In water, saturated concentration is reached at 12.92 mM with the help of sonication. Cibacron Blue F3GA has a wide specificity for nucleotide-binding proteins or just a stereoselectivity electrostatic binding. It can be used to purify interferons, dehydrogenases, kinases, and serum albumin. For example, interferon purification from human gingival fibroblast extract using Cibacron Blue F3G-A on poly(2-hydroxyethyl methacrylate), the supporting matrix, in the form of cryogels. It has shown 97.6% purity of interferon.
Sources: en.wikipedia.org
=== Oceania === Australia: Prime Minister Anthony Albanese urged all parties to "support dialogue and diplomacy". New Zealand: Foreign Minister Winston Peters expressed that "New Zealand is concerned by and actively monitoring developments in Venezuela and expects all parties to act in accordance with international law."
=== Fuel usage === Depending on the intensity of exercise, the body preferentially utilizes certain fuel forms to meet energy demands. The two main fuel sources for aerobic exercise in the body include fat (in the form of adipose tissue) and glycogen. Amino acids can also be used as a fuel source during aerobic exercise, however in moderate proportions (around 3% of the total energy expenditure during exercise). At lower intensity aerobic exercise, the body preferentially uses fat as its main fuel source for cellular respiration, however as intensity increases the body preferentially uses glycogen stored in the muscles and liver or other carbohydrates, as it is a quicker source of energy. Aerobic exercise at low or moderate intensity is not a very efficient way to lose fat in comparison to high intensity aerobic exercise. Lipolysis (hydrolysis of triglyceride into fatty acids), not fat burning (conversion of fatty acid to carbon dioxide), explains the intensity-dependent fat mass reduction. It has been shown that fatty acid is consumed for wound healing, where moderate intensity exercise does not produce significant damage like high intensity exercise. The size of adipose tissue is determined by the magnitude of nutrient competition from muscle and lungs for cell regeneration and energy replenishment after exercise.
=== Biscuits company === In 1938, Lyons purchased the Bee Bee Biscuit Company, which manufactured biscuits from its factories in Blackpool. Six years later, Lyons changed the company's name to Symbol Biscuits Ltd. and began selling biscuits under the Symbol and Lyons brand names: one of their innovations was Maryland Cookies in 1956. In 1990, Lyons changed the Symbol Biscuits name to Lyons Biscuits Ltd.
== Food processing level == Food processing level (FPL) is a parameter used for grouping of food processing according to physical and (bio)chemical changes taking place in food materials during processing. Definition of the extent of processing benefits from the use of an ordinal level of measurement. Arbitrary grouping of processed food using nominal scales, such as extent of change, nature of change, raw material sources, ingredients used, place of processing, purpose of processing, traditional, novel and other type of treatments is often criticised. Ranking of food processing at an ordinal scale at any stage from food production in agriculture to eating by consumer describes the extent of food processing using the order of the different levels of processing. Processed food classifications often identify processing as a criterion for the grouping of processed foods. Some processed food classifications, such as the Nova classification, emphasise the role of processing in the development of obesity and noncommunicable diseases. The public health interest is particularly in the Nova category of ultra-processed foods, a highly processed foods category, which often causes controversy on whether ingredients of processed foods or food processing relate to adverse health outcomes.
===== MeSH D08.811.913.050 – acyltransferases (EC 2.3) ===== MeSH D08.811.913.050.080 – acetyl-CoA C-acyltransferase MeSH D08.811.913.050.134 – acetyltransferases MeSH D08.811.913.050.134.029 – acyl-carrier protein s-acetyltransferase MeSH D08.811.913.050.134.060 – acetyl-CoA C-acetyltransferase MeSH D08.811.913.050.134.105 – amino-acid n-acetyltransferase MeSH D08.811.913.050.134.150 – carnitine O-acetyltransferase MeSH D08.811.913.050.134.170 – chloramphenicol o-acetyltransferase MeSH D08.811.913.050.134.180 – choline o-acetyltransferase MeSH D08.811.913.050.134.310 – dihydrolipoyllysine-residue acetyltransferase MeSH D08.811.913.050.134.375 – glucosamine 6-phosphate n-acetyltransferase MeSH D08.811.913.050.134.407 – histone acetyltransferases MeSH D08.811.913.050.134.440 – p300-CBP coactivator family MeSH D08.811.913.050.134.440.249 – creb-binding protein MeSH D08.811.913.050.134.440.600 – e1a-associated p300 protein MeSH D08.811.913.050.134.700 – phosphate acetyltransferase MeSH D08.811.913.050.134.850 – serine O-acetyltransferase MeSH D08.811.913.050.170 – acyl-carrier protein s-malonyltransferase MeSH D08.811.913.050.173 – 1-acylglycerol-3-phosphate O-acyltransferase MeSH D08.811.913.050.175 – 1-acylglycerophosphocholine O-acyltransferase MeSH D08.811.913.050.200 – aminoacyltransferases MeSH D08.811.913.050.200.400 – gamma-glutamylcyclotransferase MeSH D08.811.913.050.200.500 – gamma-glutamyltransferase MeSH D08.811.913.050.200.700 – peptidyl transferases MeSH D08.811.913.050.200.800 – transglutaminases MeSH D08.811.913.050.200.800.300 – factor xiiia MeSH D08.811.913.050.276 – 5-aminolevulinate synthetase MeSH D08.811.913.050.294 – arylalkylamine n-acetyltransferase MeSH D08.811.913.050.313 – arylamine N-acetyltransferase MeSH D08.811.913.050.331 – atp citrate (pro-s)-lyase MeSH D08.811.913.050.350 – carnitine acyltransferases MeSH D08.811.913.050.350.170 – carnitine O-acetyltransferase MeSH D08.811.913.050.350.200 – carnitine o-palmitoyltransferase MeSH D08.811.913.050.368 – citrate (Si)-synthase MeSH D08.811.913.050.387 – diacylglycerol o-acyltransferase MeSH D08.811.913.050.425 – glycerol-3-phosphate O-acyltransferase MeSH D08.811.913.050.600 – homoserine O-succinyltransferase MeSH D08.811.913.050.612 – hydroxymethylglutaryl-CoA synthase MeSH D08.811.913.050.614 – 2-isopropylmalate synthase MeSH D08.811.913.050.618 – malate synthase MeSH D08.811.913.050.622 – 3-oxoacyl-(acyl-carrier-protein) synthase MeSH D08.811.913.050.625 – phosphatidylcholine-sterol O-acyltransferase MeSH D08.811.913.050.646 – retinol O-fatty-acyltransferase MeSH D08.811.913.050.668 – serine C-palmitoyltransferase MeSH D08.811.913.050.712 – sphingosine N-acyltransferase MeSH D08.811.913.050.799 – sterol O-acyltransferase
Sources: en.wikipedia.org
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.
Reference material is usually kept cold, dry, and protected from light. Frozen aliquots reduce repeated freeze-thaw cycles.
No approved pharmaceutical product exists, so manufacturing and quality controls are not standardized. Products may contain different compounds or impurities.
Rodent studies reported increased endurance and fat oxidation after GW501516 exposure. Long-term studies also found higher rates of some tumors, which led to halted development.