Everything below concerns PPARδ agonist. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-11-10. Where a claim depends on a specific study, the study is described rather than over-claimed.
Cardarine is a synthetic compound also known as GW501516, GW-501516, and sometimes endurobol. It was developed as a selective agonist of peroxisome proliferator-activated receptor delta, a nuclear receptor involved in fatty acid oxidation and energy metabolism. The compound was studied in preclinical models for metabolic and cardiovascular conditions, but it did not become a marketed human medicine. In regulatory and anti-doping contexts, it is treated as a prohibited substance rather than a licensed medicine.
The pharmacological interest in cardarine centers on PPARδ activation and its downstream effects on lipid handling and mitochondrial function. In animal studies, PPARδ agonists have been associated with changes in exercise endurance and fatty acid utilization, though results vary by model and protocol. Human data remain sparse, and the absence of large controlled trials limits conclusions about efficacy. Researchers often describe the compound as a tool for probing PPARδ biology rather than a proven therapeutic agent.
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.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | GW501516, GW-501516, GW 501516, endurobol | Names vary in research and anti-doping documents. |
| Chemical class | Synthetic PPARδ agonist | Small-molecule nuclear receptor ligand. |
| CAS Registry Number | 317318-70-0 | Identifier commonly associated with GW501516. |
| Appearance | White to off-white powder | Typical for purified research material. |
| Solubility | Low in water; soluble in DMSO and ethanol | Organic solvents are common for laboratory stock solutions. |
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.
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.
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
After releasing Half-Life 2 in 2004, Valve began developing a trilogy of episodic sequels, planning to release shorter games more frequently. Half-Life 2: Episode One was released in 2006, followed by Episode Two in 2007, which ended on a cliffhanger. Episode Three was scheduled for 2008, but was canceled. The Half-Life: Alyx project lead, Robin Walker, said that Valve uses the Half-Life series to "solve some interesting collision of technology and art that had reared itself", but had failed to find a unifying idea that provided a sense of "wonderment, or opening, or expansion" for Episode Three. After the release of Left 4 Dead in 2008, Valve abandoned episodic development and made several failed attempts to develop further Half-Life projects. They decided to complete their new engine, Source 2, before beginning a new game, as developing Half-Life 2 and the Source engine simultaneously had created problems. In 2016 and 2017, the Half-Life writers Marc Laidlaw, Erik Wolpaw, Jay Pinkerton and Chet Faliszek left Valve. Coupled with Valve's support for their other franchises, journalists took the departures as an indicator that new Half-Life games were no longer in development. Walker blamed the lack of progress on Valve's flat management structure, whereby employees decide what to work on themselves. The team decided they would be happier if they worked together on a large project, even if it was not everyone's preferred choice. By 2013, Valve was experimenting with VR using Half-Life 2 as a basis.
), as shown by the equations. The distribution coefficient is calculated as the ratio between the concentration of the metal cations in the organic and aqueous phase, whereas the separation factor is calculated as the ratio between the two distribution coefficients.
Bill 28 imposes a contract on CUPE, and makes it illegal to strike, setting fines of $4000 for workers. The bill invokes the notwithstanding clause, shielding it from being struck down by the courts by allowing the bill to operate despite the right to collective bargaining granted by the Canadian Charter of Rights and Freedoms. The legislation was widely condemned, including by opposition parties, the Canadian Civil Liberties Association, Prime Minister Justin Trudeau, Minister of Justice and Attorney General of Canada David Lametti, the Ontario Bar Association, and other unions including those which had previously endorsed the PC Party. Despite the government's bill, CUPE went on strike anyway, resulting in province-wide school closures and protests in support of education workers. The government challenged CUPE at the Ontario Labour Relations Board. On November 7, 2022, Ford announced that he would rescind Bill 28 and that he would resume negotiations with CUPE. Following the strike, Ford said he did not regret his use of the notwithstanding clause in imposing the contract and said that it helped both sides "come to their senses". Following Paul Calandra's appointment as minister of education in 2025, he began appointing supervisors to take over several of Ontario's school boards. The government's Bill 33 would give the education ministry more power over school boards. In early 2026, Calandra announced the "Putting Student Achievement First Act," which includes many education reforms.
Sources: en.wikipedia.org
== External links == Clinical trial number NCT02861534 for "A Study of Vericiguat in Participants With Heart Failure With Reduced Ejection Fraction (HFrEF) (MK-1242-001) (VICTORIA)" at ClinicalTrials.gov
widespread use of third-party information reporting for tax collection purposes (ensuring a low level of tax evasion) broad tax bases (ensuring a low level of tax avoidance) a strong subsidization of goods that are complementary to working (ensuring a high level of labour force participation). in 2023, Denmark considered methods to increase taxes on energy dealers.
== See also == Hydrogen sensor Localized surface plasmon Multi-parametric surface plasmon resonance Nano-optics Plasmon Quartz crystal microbalance Spinplasmonics Spreeta Surface plasmon polariton Waves in plasmas
Sources: en.wikipedia.org
Cardarine is an investigational synthetic compound that acts as a PPARδ agonist. It is also known as GW501516 and has been studied mainly in preclinical research. It is not an approved medicine.
No. Cardarine is not a steroid hormone; it targets the nuclear receptor PPARδ. Its classification in anti-doping rules differs from anabolic steroids, though it remains prohibited in sport.
Early rodent studies reported tumor formation at multiple sites, which raised safety concerns. Sponsors stopped clinical development, and no approved human product exists.
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.