Preclinical research is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2025-10-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Cardarine is a common name for GW501516, a synthetic compound first described in the 1990s as a selective agonist of the peroxisome proliferator-activated receptor delta. It was studied in preclinical models for metabolic and cardiovascular conditions, but it has not been approved as a medicine in the United States, Europe, or other major jurisdictions. Retail products labeled as cardarine are generally research chemicals or supplements, not pharmaceutical formulations. Because human safety and efficacy data remain limited, regulatory agencies treat it as an unapproved substance rather than a therapeutic product.
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.
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.
| Property | Value | Notes |
|---|---|---|
| IUPAC name | {4-[({4-methyl-2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-5-yl}methyl)sulfanyl]phenoxy}acetic acid | Systematic name for GW501516 |
| CAS Registry Number | 317318-70-0 | Unique identifier for the parent compound |
| Molecular formula | C21H18F3NO3S2 | Includes carbon, hydrogen, fluorine, nitrogen, oxygen, and sulfur |
| Molecular weight | 453.5 g/mol | Approximate value for the neutral form |
| Appearance | White to off-white powder | Typical description for purified laboratory material |
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.
Preclinical research reported that GW501516 increased running endurance in mice and improved lipid profiles in some animal species. Early human trials explored effects on high-density lipoprotein cholesterol, triglycerides, and glucose handling, but the program was discontinued. Published human data are sparse and do not establish efficacy for any condition. Studies also examined PPAR delta in cancer biology, with conflicting findings across models. The relationship between receptor activation, tissue context, and disease risk remains an active area of investigation.
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 selective agonist at PPARδ, a nuclear receptor that regulates transcription of genes involved in lipid handling and energy metabolism. Activation of PPARδ in preclinical models increases fatty acid oxidation, mitochondrial biogenesis, and exercise endurance in rodents. These effects have made the compound a subject of metabolic research and also a target for sport anti-doping rules. In humans, however, controlled studies are limited, and whether similar endurance or metabolic changes occur at tolerated exposures remains an open question. The receptor’s broad tissue distribution also means downstream effects may vary by organ and condition.
Detection of GW501516 in biological samples generally relies on liquid chromatography coupled with tandem mass spectrometry. Urine is a common matrix in anti-doping analysis, while blood or plasma may be used in research settings. Sample preparation can involve enzymatic hydrolysis, protein precipitation, or solid-phase extraction before instrumental analysis. Because the compound undergoes metabolism, assays may target the parent molecule, one or more metabolites, or both. Detection windows are not fixed; they depend on factors such as dose, route, individual metabolism, and assay sensitivity. Reference standards are required for accurate identification and quantification.
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.
Micelles consist of a hydrophobic inner core surrounded by a hydrophilic outer shell that is exposed to a solvent, and their structures can be spheres, disks or wormlike assemblies. Micelles form spontaneously when the concentration is above a critical micelle concentration and temperature. Amphiphiles with an intermediate level of hydrophobicity prefer to assemble into bilayer vesicles. Vesicles are spherical, hollow, lamellar structures that surround an aqueous core. The hydrophobic moiety faces inwards and forms the inner section of the bilayer, and the hydrophilic moiety is exposed to the aqueous environment on the inner and outer surface. Micelle structures have a hydrophobic interior and hydrophilic exterior. There is normally a distinct relationship between the amphiphilic character of a peptide and its function in that the amphiphilic character determines the self-assembly properties, and in turn this is what gives the peptide its functionality. The level of amphiphilicity can vary significantly in peptides and proteins; as such they can display regions that are either hydrophobic or hydrophilic in nature. An example of this is the cylindrical structure of an α-helix, as it could contain a section of hydrophobic residues along one face of the cylinder and a hydrophilic section of residues on the opposite face of the cylinder. For β-sheet structures, the peptide chain can be composed of alternating hydrophilic and hydrophobic residues, so that the side chains of the residues are displayed on opposite faces of the sheet.
Acquired generalized lipodystrophy (Lawrence syndrome, Lawrence–Seip syndrome) Adiposis dolorosa (Dercum's disease) Alpha-1 antitrypsin deficiency panniculitis (alpha1-protease deficiency panniculitis, alpha1-proteinase deficiency panniculitis) Atrophic connective tissue panniculitis Barraquer–Simons syndrome (acquired partial lipodystrophy, cephalothoracic lipodystrophy, progressive lipodystrophy) Benign symmetric lipomatosis (benign symmetric lipomatosis of Launois–Bensaude, Madelung's disease) Centrifugal abdominal lipodystrophy (centrifugal lipodystrophy, lipodystrophia centrifugalis abdominalis infantalis) Chronic erythema nodosum (erythema nodosum migrans, subacute migratory panniculitis of Vilanova and Piñol, subacute nodular migratory panniculitis) Cold panniculitis (popsicle panniculitis) Congenital generalized lipodystrophy (Berardinelli–Seip syndrome) Cytophagic histiocytic panniculitis Drug-induced lipodystrophy Factitial panniculitis Familial partial lipodystrophy (Köbberling–Dunnigan syndrome) Gouty panniculitis Hemihyperplasia–multiple lipomatosis syndrome HIV-associated lipodystrophy Involutional lipoatrophy Lipoatrophia annularis (Ferreira–Marques lipoatrophia) Lipoatrophia semicircularis (semicircular lipoatrophy) Lipodermatosclerosis (chronic panniculitis with lipomembranous changes, hypodermitis sclerodermiformis, sclerosing panniculitis, stasis panniculitis) Lipohypertrophy Localized lipodystrophy Neutrophilic lobular panniculitis Nodular vasculitis Non-progressive late-onset linear hemifacial lipoatrophy Pancreatic panniculitis (enzymatic panniculitis, pancreatic fat necrosis, subcutaneous fat necrosis) Poland's syndrome Post-steroid panniculitis Sclerema neonatorum Sclerosing lipogranuloma (paraffinoma) Septal panniculitis Subcutaneous fat necrosis of the newborn Traumatic panniculitis Tumor lysis syndrome Weber–Christian disease (relapsing febrile nonsuppurative panniculitis)
Anthraquinone type: Many acid dyes are synthesized from chemical intermediates that form anthraquinone-like structures as their final state. Many blue dyes have this structure as their basic shape. The structure predominates in the leveling class of acid dye. Azo dyes: The structure of azo dyes contains the azo group (R-N=N−R. Most azo dyes are not acid dyes, but many acid dyes are azo dyes. Many acid dyes of the azo type are red in color. Triarylmethane dye: These predominate in the milling class of dye. There are many yellow and green dyes commercially applied to fibers that are related to triphenylmethane.
Sources: en.wikipedia.org
== Applications in biochemistry == Coomassie brilliant blue R-250 was first used to visualise proteins in 1963 by Fazekas de St. Groth and colleagues. Protein samples were separated electrophoretically on a cellulose acetate sheet. The sheet was then soaked in sulfosalicylic acid to fix the protein bands and transferred to a solution of the dye. Two years later in 1965 Meyer and Lambert used Coomassie brilliant blue R-250 to stain protein samples after electrophoretic separation in a polyacrylamide gel. They soaked the gel in a dye solution containing methanol, acetic acid and water. As the dye stained the polyacrylamide gel as well as the protein, in order to visualise the protein bands they needed to destain the gel, which they did electrophoretically. Subsequent publications reported that polyacrylamide gels could be successfully destained using an acetic acid solution. The first report of the use of the G form of the dye to visualise protein bands in polyacrylamide gels came in 1967, where the dye was dissolved in an acetic acid solution containing methanol. It was subsequently discovered that the protein bands could be stained without staining the polyacrylamide by using a colloid of the G form of the dye in a trichloroacetic acid solution containing no methanol. With this procedure it was no longer necessary to destain the gel. Modern formulations typically use a colloid of the G form of dye in a solution containing phosphoric acid, ethanol (or methanol) and ammonium sulfate (or aluminium sulfate).
Theodore Ryder (September 14, 1916 – March 8, 1993), often called Ted or Teddy Ryder, was, at the age of five, one of the first twelve people with diabetes in the world to be treated using insulin. When he died in 1993 at the age of 76, he became the world's first person to live 70 years with diabetes and probably the longest documented case of sustained insulin treatment in medical history. He was also the last survivor of the first twelve diabetes patients treated with insulin.
Marguerite Yourcenar (UK: , US: ; French: [maʁɡ(ə)ʁit juʁsənaʁ] ; born Marguerite Antoinette Jeanne Marie Ghislaine Cleenewerck de Crayencour; 8 June 1903 – 17 December 1987) was a Belgian-born French novelist and essayist who became a US citizen in 1947. Winner of the Prix Femina and the Erasmus Prize, she was the first woman elected to the Académie Française, in 1980. In 1965, she was nominated for the Nobel Prize in Literature.
Sources: en.wikipedia.org
Although the exact ion formation mechanism is not clear, water can be ionized directly by Penning ionization. Another proposal is that water is ionized by the same mechanism that has been proposed for atmospheric pressure chemical ionization
The CureVac COVID-19 vaccine (abbreviated CVnCoV) was a COVID-19 vaccine candidate developed by CureVac N.V. and the Coalition for Epidemic Preparedness Innovations (CEPI). The vaccine showed inadequate results in its Phase III trials with only 47% efficacy. In October 2021 CureVac abandoned further development and production plans for CVnCoV and refocused efforts on a cooperation with GlaxoSmithKline.
CSL's vaccine for swine flu, the world's first, was approved in September 2009 for use by people over age 10. The federal government ordered 21 million doses of vaccine for Australians. CSL also provided vaccines for customers in Singapore and the US. On 28 September 2010, the Australian Therapeutic Goods Administration (TGA) conducted an analysis of febrile convulsions following immunisation in children following monovalent pandemic H1N1 vaccine (Panvax/Panvax Junior, CSL). A paper published in the Medical Journal of Australia provides a possible reason for CSL's 2010 flu vaccine causing febrile convulsions in children. The authors hypothesise that suboptimal use of the detergent called deoxycholate – used in the manufacturing process by CSL (one of the few vaccine manufacturers that use it) – to split the flu virus from its membrane may be at fault.
Sources: en.wikipedia.org
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.
It is prohibited by the World Anti-Doping Agency as a hormone and metabolic modulator. Athletes who test positive for GW501516 can face sanctions, including suspensions and loss of results.
Cardarine is a common or trade-style name, while GW501516 is the research code for the same chemical entity. Some sources also use Endurobol or GSK-516. The names refer to the same compound, not distinct drugs.
Anti-doping and clinical laboratories commonly use liquid chromatography-tandem mass spectrometry. The method can identify GW501516 and its metabolites in urine or blood. Detection depends on sample timing and the amount present.