Everything below concerns Nuclear receptor. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-07-16. Where a claim depends on a specific study, the study is described rather than over-claimed.
Literature on cardarine often separates receptor pharmacology from toxicology. Mechanistic papers describe PPARδ activation and gene expression changes, while safety assessments focus on carcinogenicity and species differences. Questions remain about whether rodent tumors arise through PPARδ-dependent or off-target mechanisms. Another open area is how human metabolism and exposure compare with those in animal studies. Analytical methods such as liquid chromatography–mass spectrometry are used to confirm identity in biological and product samples.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Primary target | PPARδ | Nuclear receptor; not androgen receptor |
| Studied indications | Dyslipidemia; obesity; diabetes | Early clinical research; development discontinued |
| Rodent toxicity | Tumor formation in multiple tissues | Dose-dependent findings in some studies |
| Human approval | None | No approved therapeutic use |
| Typical analytical method | LC-MS/MS | Used for identity and quantification |
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.
Laboratory detection of GW501516 commonly uses liquid chromatography coupled with tandem mass spectrometry. The method can identify the parent compound or its metabolites in urine and blood after sample cleanup. Protein precipitation, solid-phase extraction, or enzymatic hydrolysis may precede analysis, depending on the matrix. Reference standards are required for accurate quantification and confirmation. Because the compound is not approved, testing often occurs in anti-doping, forensic, or research settings rather than routine clinical care. Results are reported with limits of detection and quantification.
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.
PPARδ is a nuclear receptor that influences transcription of genes involved in fatty acid oxidation, lipid transport, and energy homeostasis. GW501516 binds and activates this receptor with high selectivity relative to PPARα and PPARγ in laboratory assays. Activation alters expression of target genes in skeletal muscle, liver, and adipose tissue in animal models. The exact clinical consequences of these changes in humans remain incompletely characterized, and observed effects in animals do not establish therapeutic benefit or safety.
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.
=== Age === Historically, obesity primarily affected adults, but childhood obesity has grown significantly in recent decades. From the mid-1980s to the mid-2010s, obesity roughly doubled among U.S. children ages 2 to 5 and roughly tripled among young people over the age of 6. Overall, obesity in the United States peaks during the middle aged years. During the period 2015–16, the prevalence of obesity among adults aged 20–39 was 35.7%, among those aged 40–59, 42.8%, and among those 60 and over, 41.0%.
Gas chromatography-mass spectrometry (GC-MS) is a two-dimensional chromatography technique that combines the separation technique of gas chromatography with the identification technique of mass spectrometry. GC-MS is the single most important analytical tool for the analysis of volatile and semi-volatile organic compounds in complex mixtures. It works by first injecting the sample into the GC inlet where it is vaporized and pushed through a column by a carrier gas, typically helium. The analytes in the sample are separated based upon their interaction with the coating of the column, or the stationary phase, and the carrier gas, or the mobile phase. The compounds eluted from the column are converted into ions via electron impact (EI) or chemical ionization (CI) before traveling through the mass analyzer. The mass analyzer serves to separate the ions on a mass-to-charge basis. Popular choices perform the same function but differ in the way that they accomplish the separation. The analyzers typically used with GC-MS are the time-of-flight mass analyzer and the quadrupole mass analyzer. After leaving the mass analyzer, the analytes reach the detector and produce a signal that is read by a computer and used to create a gas chromatogram and mass spectrum. Sometimes GC-MS utilizes two gas chromatographers in particularly complex samples to obtain considerable separation power and be able to unambiguously assign the specific species to the appropriate peaks in a technique known as GCxGC-(MS).
=== Lyophilized === Lyophilized drugs are stored in vials, cartridges, dual chamber syringes, and prefilled mixing systems. Lyophilization, or freeze drying, is a process that removes water from a liquid drug creating a solid powder, or cake. The lyophilized product is stable for extended periods of time and could allow storage at higher temperatures. In protein formulations, stabilizers are added to replace the water and preserve the structure of the molecule. Before administration, a lyophilized drug is reconstituted as a liquid before being administered. This is done by combining a liquid diluent with the freeze-dried powder, mixing, then injecting. Reconstitution usually requires a reconstitution and delivery system to ensure that the drug is correctly mixed and administered.
Louis, Missouri; Integrative Technologies for Advancing Scientific Cores ABRF 2014, 23–25 March, Albuquerque, New Mexico; Team Science and Big Data: Cores at the Frontier ABRF 2013, 2–5 March, Palm Springs, California; Tools for the Advancement of Convergence Science ABRF 2012, 17–20 March, Orlando, Florida; Learning From Biomolecules ABRF 2011, 19–22 February, San Antonio, Texas; Technologies to Enable Personalized Medicine ABRF 2010, 20–23 March, Sacramento, California; Translating Basic Research With Advances in Biomolecular Technology ABRF 2009, 7–10 February, Memphis, Tennessee; Application and Optimization of Existing and Emerging Biotechnologies ABRF 2008, 9–12 February, Salt Lake City, Utah; Enabling Technologies in the Life Sciences ABRF 2007, 31 March- 3 April, Tampa, Florida; Creating the Biological Roadmap ABRF 2006, 11–14 February, Long Beach, California; Integrating Science, Tools and Technologies with Systems Biology ABRF 2005, 5–8 February, Savannah, Georgia; BioMolecular Technologies: Discovery to Hypothesis ABRF 2004, 28 February – 2 March, Portland, Oregon; Integrating Technologies in Proteomics and Genomics ABRF 2003, 10–13 February, Denver, Colorado; Translating Biology Using Proteomics and Functional Genomics ABRF 2002, 9–12 March, Austin, Texas; Biomolecular Technologies: Tools for Discovery in Proteomics and Genomics ABRF 2001, 24–27 February, San Diego, CA; The New Biology: Technology for resolving Macromolecular Communications ABRF 2000, 19–22 February, Bellevue, Washington; From Singular to Global Analyses of Biological Systems ABRF 1999, 19–22 March, Durham, North Carolina; Bioinformatics and Biomolecular Technologies: Linking Genomes, Proteomes and Biochemistry ABRF 1998, 21–24 March, San Diego, California; From Genomes to Function – Technical Challenges of the Post-Genome Era ABRF 1997, 9–12 February, Baltimore, Maryland; Techniques at the Genome-Proteome Interface ABRF 1996, 30 March – 2 April, San Francisco, California; Biomolecular Techniques
epidemic in the 2000s is related to a number of factors. Rates of opioid use and dependency vary by age, sex, race, and socioeconomic status. With respect to race, the discrepancy in deaths is thought to be due to an interplay between physician prescribing and lack of access to healthcare and certain prescription drugs. Men are at higher risk for opioid use and dependency than women, and men also account for more opioid overdoses than women, although this gap is closing. Women are more likely to be prescribed pain relievers, be given higher doses, use them for longer durations, and become dependent upon them faster. Deaths due to opioid use also tend to skew at older ages than deaths from use of other illicit drugs. This does not reflect opioid use as a whole, which includes younger people. Overdoses from opioids are highest among people between the ages of 40 and 50, in contrast to heroin overdoses, which are highest among people between the ages of 20 and 30. 21- to 35-year-olds represent 77% of people who enter treatment for opioid use disorder, but the average age of first-time use of prescription painkillers was 21.2 years in 2013. Among the middle class, means of acquiring funds include elder financial abuse and international dealers noticing a lack of enforcement in their transaction scams throughout the Caribbean.
Sources: en.wikipedia.org
Choose the best candidates from pre-clinical (animal) studies A 2006 analysis of studies for 1,026 therapies in stroke and theorized that the best drugs from pre-clinical studies were not the ones being brought into clinical trials. Many of the drugs with the strongest signals in pre-clinical models were not the ones later brought into clinical trials. Improve pre-clinical testing Others proposed that the lack of standardization in pre-clinical models made it difficult to select the best drugs. One attempt to address this comes from the National Institute of Neurological Disorders and Stroke which started the Stroke Preclinical Assessment Network to fund a testing regimen that will allow head-to-head comparisons of different drugs. Treat patients early enough After the onset of stroke, the amount of brain tissue that dies increases over time, leading to the saying, "Time is brain." Treating patients earlier can lead to a greater amount of brain tissue being saved. Protect the brain for long enough An element of clinical trial design that affects the probability that a truly beneficial drug will show benefit is the duration of protection. A truly effective drug that is tested in a clinical trial where it protects the brain for a longer period of time would be expected to show a greater benefit verses a placebo than the same drug in a different clinical trial where it only protects the brain for a shorter period of time.
As of 2023, steatotic liver disease (SLD) has been chosen as an umbrella term encompassing different disease subcategories that begin with fatty accumulation (hepatic steatosis) in more than 5% of hepatocytes. When at least one metabolic risk factor is present, the condition is termed metabolic dysfunction–associated steatotic liver disease (MASLD). If there is also increased alcohol intake, the term MetALD (metabolic dysfunction and alcohol-related liver disease) is used. This is differentiated from alcohol-related liver disease (ALD), in which alcohol is the predominant cause of the steatotic liver disease. MASLD is thus distinguished from other causes (etiologies) such as cryptogenic SLD, drug-induced liver injury (DILI), and monogenic diseases. By various mechanisms and possible insults to the liver, SLD may progress to steatohepatitis (MASH), a state in which steatosis is combined with inflammation and sometimes fibrosis. MASH can then lead to complications such as cirrhosis and hepatocellular carcinoma.
Only the imine nitrogen (HC=N-CH) of imidazole is basic, and it is this nitrogen that binds to metal ions. Imidazole is a pure sigma-donor ligand. The pKa of protonated imidazolium cation is about 6.95, which indicates that the basicity of imidazole is intermediate between pyridine (pKa of pyridinium = 5.23) and ammonia (pKa = 9,24 of ammonium). The donor properties of imidazole can also inferred from the redox properties of its complexes. It is classified as an L ligand in the Covalent bond classification method. In the usual electron counting method, it is a two-electron ligand. Imidazole is classified as L ligand in the covalent bond classification method. In the usual electron counting method, it is a two-electron ligand. With respect to HSAB theory, imidazole can be classified as hard ligand. Nonetheless, complexes between low-valent metals and imidazole are well known, e.g., [Re(imidazole)3(CO)3]+. As a ligand, imidazole is compact and flat. The M-N(imidazole) bond is freely rotating. Six imidazole ligands fit comfortably around octahedral metal centers, e.g., [Fe(imidazole)6]2+. Homoleptic octahedral complexes have been characterized by X-ray crystallography for the following dications: Fe2+, Co2+, Ni2+, Zn2+, Cd2+. Hexakis complexes of both Ru2+ and Ru3+ are also known. Cu2+, Pd2+, and Pt2+ form homoleptic square planar complexes. Zn2+, although crystallized as the hexakis complex, more typically forms a tetrahedral complex.
== Grading == For the Class 10 and Class 12 exams, CBSE (along with the marks obtained) includes the positional grade, which is based on the average performance of students in that subject. Consequently, the cutoffs required to obtain a particular grade vary from year to year.
All of the alkali metals except lithium and caesium have at least one naturally occurring radioisotope: sodium-22 and sodium-24 are trace radioisotopes produced cosmogenically, potassium-40 and rubidium-87 have very long half-lives and thus occur naturally, and all isotopes of francium are radioactive. Caesium was also thought to be radioactive in the early 20th century, although it has no naturally occurring radioisotopes. (Francium had not been discovered yet at that time.) The natural long-lived radioisotope of potassium, potassium-40, makes up about 0.012% of natural potassium, and thus natural potassium is weakly radioactive. This natural radioactivity became a basis for a mistaken claim of the discovery for element 87 (the next alkali metal after caesium) in 1925. Natural rubidium is similarly slightly radioactive, with 27.83% being the long-lived radioisotope rubidium-87. Caesium-137, with a half-life of 30.17 years, is one of the two principal medium-lived fission products, along with strontium-90, which are responsible for most of the radioactivity of spent nuclear fuel after several years of cooling, up to several hundred years after use. It constitutes most of the radioactivity still left from the Chernobyl accident. Caesium-137 undergoes high-energy beta decay and eventually becomes stable barium-137. It is a strong emitter of gamma radiation. Caesium-137 has a very low rate of neutron capture and cannot be feasibly disposed of in this way, but must be allowed to decay.
Sources: en.wikipedia.org
It targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not act primarily on androgen receptors. This distinction separates it from SARMs.
Rodent studies found dose-dependent tumors in several organs. The sponsor discontinued the program over cancer concerns. Human risk from long-term use remains unknown.
Controlled human endurance trials are lacking. Animal studies show increased exercise capacity under some conditions. Anecdotal reports are not equivalent to clinical evidence.
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.