The short version of PPARδ fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-02-04. Anything still debated is marked as such rather than presented as settled.
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.
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 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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white solid | Typical form of reference material |
| Solubility | Low in water; soluble in DMSO | Used to prepare stock solutions |
| Typical storage | -20 °C, desiccated, protected from light | Common laboratory practice |
| Analytical method | LC-MS/MS | Detects parent compound and metabolites |
| Common test matrix | Urine or blood | Used in anti-doping analysis |
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.
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.
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.
If sanitation standards are not maintained, these markets can spread disease. Those that carry live animals and wildlife are at especially high risk of transmitting zoonoses. Because of the openness, newly introduced animals may come in direct contact with sales clerks, butchers, and customers or to other animals which they would never interact with in the wild. This may allow for some animals to act as intermediate hosts, helping a disease spread to humans. Outbreaks of zoonotic diseases including COVID-19, H5N1 avian flu, severe acute respiratory syndrome (SARS), and monkeypox have been traced to live wildlife markets where the potential for zoonotic transmission is greatly increased. Wildlife markets in China have been implicated in the 2002 SARS outbreak; it is thought that the market environment provided optimal conditions for the coronaviruses of zoonotic origin that caused both outbreaks to mutate and subsequently spread to humans. The exact origin of the COVID-19 pandemic is yet to be confirmed as of February 2021 and was originally linked to the Huanan Seafood Wholesale Market in Wuhan, China due to reports that two-thirds of the initial cases had direct exposure to the market, although a 2021 WHO investigation concluded that the Huanan market was unlikely to be the origin due to the existence of earlier cases. Due to unhygienic sanitation standards and the connection to the spread of zoonoses and pandemics, critics have grouped live animal markets together with factory farming as major health hazards in China and across the world.
== History == Zydis technology was developed by R.P. Scherer Corporation (currently owned by Catalent Pharma Solutions) in 1986. The technology's first commercial application was in August, 1993, when a new dosage form of Pepcidine (famotidine) from Merck & Co. was launched in Sweden. In November 1993 Imodium Lingual (loperamide) from Janssen Pharmaceutica was released in Germany with Zydis technology. In December, 1996, the Food and Drug Administration approved Claritin (loratadine) RediTabs from Schering-Plough, the first prescription drug with Zydis technology sold in the U.S.
The following is a partial list of the "D" codes for Medical Subject Headings (MeSH), as defined by the United States National Library of Medicine (NLM). This list continues the information at List of MeSH codes (D06). Codes following these are found at List of MeSH codes (D09). For other MeSH codes, see List of MeSH codes. The source for this content is the set of 2006 MeSH Trees from the NLM.
Sources: en.wikipedia.org
== Atrocities and illegal activities == The Selous Scouts had a reputation for brutality. The unit conducted a number of atrocities against villages that were believed to have collaborated with the guerrillas. Members of the units also poached ivory, smuggled guns and beat and killed civilians. During attacks into Botswana, the Selous Scouts committed arson and abducted civilians. The use of insurgent uniforms and civilian clothing by the Selous Scouts may also have violated the 1907 Hague Convention and the Geneva Conventions which prohibit military personnel from wearing enemy uniforms in most circumstances and require that they clearly distinguish themselves from civilians. Some of the actions undertaken by the Selous Scouts were illegal under Rhodesian law. Selous Scout teams at times attacked Rhodesian Security Forces units and white farms in attempts to persuade local civilians that they were actually insurgents. Another tactic involved repeatedly calling in air strikes and fireforce attacks on insurgents after they had left a specific kraal leading the insurgents to kill innocent civilians in the kraal because they suspected civilians of informing on their positions; it was intended that this would sow divisions between the insurgents and civilians. The Selous Scouts also labelled insurgents as traitors to the insurgent cause and then publicly killed them leading to "disillusionment and bewilderment" among local civilians; this led to several murder investigations being opened into members of the unit.
The most stable and dense form of selenium is gray and has a chiral hexagonal crystal lattice (space group 152 or 154 depending on the chirality) consisting of helical polymeric chains, where the Se–Se distance is 237.3 pm and Se–Se–Se angle is 103.1°. The minimum distance between chains is 343.6 pm. Gray selenium is formed by mild heating of other allotropes, by slow cooling of molten selenium, or by condensing selenium vapor just below the melting point. Whereas other selenium forms are insulators, gray selenium is a semiconductor showing appreciable photoconductivity. Unlike the other allotropes, it is insoluble in CSs. It resists oxidation by air and is not attacked by nonoxidizing acids. With strong reducing agents, it forms polyselenides. Selenium does not exhibit the changes in viscosity that sulfur undergoes when gradually heated.
There are a number of studies that have been conducted to determine research and development costs: notably, recent studies from DiMasi and Wouters suggest pre-approval capitalized cost estimates of $2.6 billion and $1.1 billion, respectively. The figures differ significantly based on methodologies, sampling and timeframe examined. Several other studies looking into specific therapeutic areas or disease types suggest as low as $291 million for orphan drugs, $648 million for cancer drugs or as high as $1.8 billion for cell and gene therapies. The average cost (2013 dollars) of each stage of clinical research was US$25 million for a Phase I safety study, $59 million for a Phase II randomized controlled efficacy study, and $255 million for a pivotal Phase III trial to demonstrate its equivalence or superiority to an existing approved drug, possibly as high as $345 million. The average cost of conducting a 2015–16 pivotal Phase III trial on an infectious disease drug candidate was $22 million. The full cost of bringing a new drug (i.e., new chemical entity) to market—from discovery through clinical trials to approval—is complex and controversial. In a 2016 review of 106 drug candidates assessed through clinical trials, the total capital expenditure for a manufacturer having a drug approved through successful Phase III trials was $2.6 billion (in 2013 dollars), an amount increasing at an annual rate of 8.5%.
Sources: en.wikipedia.org
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.
PPARδ is a nuclear receptor that regulates genes linked to fatty acid oxidation and energy metabolism. Activation can alter lipid handling and energy use in experimental models. The full range of effects in humans is still under study.
The solid compound is generally stable when kept cold, dry, and protected from light. Solutions may degrade faster, so laboratory protocols often specify fresh preparation or cold storage. Stability can depend on solvent, concentration, and container.
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.