GW501516 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.
Last reviewed on 2026-04-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
In laboratory settings, cardarine is studied as a tool compound for probing PPARδ biology. Published experiments often use cell cultures, rodent models, or isolated tissues. Some investigations focus on metabolic effects, while others assess potential risks such as carcinogenicity observed in long-term animal studies. Because human trials are sparse, most knowledge comes from preclinical work and adverse event reports. Scientific literature frequently notes the gap between animal findings and human outcomes. The compound is not a dietary supplement and is not intended for human consumption.
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.
| Property | Value | Notes |
|---|---|---|
| CAS Registry Number | 317318-70-0 | Unique identifier for the compound. |
| Chemical class | PPARδ agonist | Synthetic ligand for peroxisome proliferator-activated receptor delta. |
| Appearance | White to off-white solid | Typical form of research-grade material. |
| Solubility | Soluble in DMSO and ethanol | Poorly soluble in water. |
| Typical storage | -20°C | Recommended for long-term storage of stock solutions. |
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 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.
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.
Darren Keith McGuire, MD, MHSc is an American cardiologist and clinical trialist specializing in cardiovascular disease prevention and cardiometabolic medicine, particularly the relationship between diabetes and heart disease. He is a Distinguished Teaching Professor of Internal Medicine in the Division of Cardiology at the University of Texas Southwestern Medical Center. He also serves as lead physician of the Parkland Health cardiology clinics and holds the Jere H. Mitchell Distinguished Chair in Cardiovascular Science.
In some eukaryotes, such as the parasitic worm Ascaris suum, an enzyme similar to complex II, fumarate reductase (menaquinol:fumarate oxidoreductase, or QFR), operates in reverse to oxidize ubiquinol and reduce fumarate. This allows the worm to survive in the anaerobic environment of the large intestine, carrying out anaerobic oxidative phosphorylation with fumarate as the electron acceptor. Another unconventional function of complex II is seen in the malaria parasite Plasmodium falciparum. Here, the reversed action of complex II as an oxidase is important in regenerating ubiquinol, which the parasite uses in an unusual form of pyrimidine biosynthesis.
The Supreme Central Junta was defeated and dissolved itself giving way to a five-member council know as the Regency, or the Council of Regency of Spain and the Indies. Next, to establish a more legitimate government system, the Regency called for the convening of an "extraordinary and general Cortes of the Spanish Nation": which was convened as the Cortes of Cádiz. At the beginning of 1810, new juntas appeared across Spanish America when the Central Junta fell to the French invasion. The Cortes of Cádiz was the first national assembly to claim sovereignty in Spain. It represented the abolition of the old kingdoms. The opening session was held on 24 September 1810, in the building now known as the Real Teatro de las Cortes under the siege of French army. It met as one body and its members represented the entire Spanish empire. The plan for the election of the Cortes, based on provinces, and not kingdoms, was more equitable and provided more time to determine what would be considered an overseas province.
==== Lungs ==== Inhaled acetylcysteine is also used post-operatively, as a diagnostic aid, and in tracheotomy care. It may be considered ineffective in cystic fibrosis. A 2013 Cochrane review in cystic fibrosis found no evidence of benefit. Acetylcysteine is used in the treatment of obstructive lung disease as an adjuvant treatment.
Sources: en.wikipedia.org
Nonribosomal peptide synthesis occurs through distinct modules that can load and extend the protein by one amino acid per module through the amide bond formation at the contact sites of the activating domains. Each module typically consists of an adenylation (A) domain, a peptidyl carrier protein (PCP) domain, and a condensation (C) domain. In the A domain, the specific amino acid is activated by converting into an aminoacyl adenylate enzyme complex attached to a 4'-phosphopantetheine cofactor by thioesterification. The complex is then transferred to the PCP domain with the expulsion of AMP. The PCP domain uses the attached 4'-phosphopantethein prosthetic group to load the growing peptide chain and their precursors. The organization of the modules necessary to biosynthesize vancomycin is shown in Figure 1. In the biosynthesis of vancomycin, additional modification domains are present, such as the epimerization (E) domain, which isomerizes the amino acid from one stereochemistry to another, and a thioesterase domain (TE) is used as a catalyst for cyclization and releases of the molecule via a thioesterase scission.
== Inhibitors == The MMPs are inhibited by specific endogenous tissue inhibitor of metalloproteinases (TIMPs), which comprise a family of four protease inhibitors: TIMP-1, TIMP-2, TIMP-3, and TIMP-4. TIMPs are small proteins made of two parts that has N-terminal domain (this is the main inhibitory part) and a C-terminal domain. Besides stopping MMPs, TIMPs can also do other jobs, like binding directly to receptors on the cell surface for signalling. There are four main TIMPs:
In 2025, Willis underwent keyhole heart surgery after medical investigations revealed that she had a congenital hole in her heart which she had been unaware of for 48 years. The condition was discovered following routine checks and further investigation after an MRI scan identified an enlargement in her heart. Willis underwent the procedure at the Royal Brompton Hospital and later publicly thanked the medical staff who treated her.
In "yellowsolve" methods, a red dye in dilute acetic acid is first applied, then the section is very thoroughly dehydrated to ensure that no moisture remains. The red dye is then displaced by a yellow dye in a solvent, such as cellosolve (2-ethoxy-ethanol). The name yellowsolve is a blend of the terms yellow and cellosolve. Lendrum's phloxine-tartrazine for cell inclusions is one example of a yellowsolve stain.
Impaired oral tolerance Gut dysbiosis Increased gut permeability Heightened immune reactivity Chemicals, which are either a part of the immediate environment or found in drugs, are key players in this context. Examples of such chemicals include hydrazines, hair dyes, trichloroethylene, tartrazines, hazardous wastes, and industrial emissions. Ultraviolet radiation has been implicated as a potential causative factor in the development of autoimmune diseases, such as dermatomyositis. Furthermore, exposure to pesticides has been linked with an increased risk of developing rheumatoid arthritis. Vitamin D, on the other hand, appears to play a protective role, particularly in older populations, by preventing immune dysfunctions. Infectious agents are also being increasingly recognized for their role as T cell activators — a crucial step in triggering autoimmune diseases. The exact mechanisms by which they contribute to disease onset remain to be fully understood. For instance, certain autoimmune conditions like Guillain-Barre syndrome and rheumatic fever are thought to be triggered by infections. Furthermore, analysis of large-scale data has revealed a significant link between SARS-CoV-2 infection (the causative agent of COVID-19) and an increased risk of developing a wide range of new-onset autoimmune diseases.
Sources: en.wikipedia.org
=== Extracellular vesicles === In 2016, Huleihel et al., reported the presence of DNA, RNA, and Matrix-bound nanovesicles (MBVs) within ECM bioscaffolds. MBVs shape and size were found to be consistent with previously described exosomes. MBVs cargo includes different protein molecules, lipids, DNA, fragments, and miRNAs. Similar to ECM bioscaffolds, MBVs can modify the activation state of macrophages and alter different cellular properties such as; proliferation, migration and cell cycle. MBVs are now believed to be an integral and functional key component of ECM bioscaffolds.
A scar (or scar tissue) is an area of fibrous tissue that replaces normal skin following an injury. Scars result from the biological process of wound repair in the skin, as well as in other organs and tissues of the body. Thus, scarring is a natural part of the healing process. With the exception of very minor lesions, every wound (for example, after an accident, disease, or surgery) results in some degree of scarring. An exception is animals with complete regeneration, which regrow tissue without scar formation. Scar tissue is composed of the same protein (collagen) as the tissue that it replaces, but the fiber composition of the protein is different; instead of a random basketweave formation of the collagen fibers found in normal tissue, in fibrosis the collagen cross-links and forms a pronounced alignment in a single direction. This collagen scar tissue alignment is usually of inferior functional quality to the normal collagen randomised alignment. For example, scars in the skin are less resistant to ultraviolet radiation, and sweat glands and hair follicles do not grow back within scar tissues. A myocardial infarction, commonly known as a heart attack, causes scar formation in the heart muscle, which leads to loss of muscular power and possibly heart failure. However, there are some tissues (e.g. bone) that can heal without any structural or functional deterioration.
=== Biological === Thorium is odourless and tasteless. The chemical toxicity of thorium is low because thorium and its most common compounds (mostly the dioxide) are poorly soluble in water, precipitating out before entering the body as the hydroxide. Some thorium compounds are chemically moderately toxic, especially in the presence of strong complex-forming ions such as citrate that carry the thorium into the body in soluble form. If a thorium-containing object has been chewed or sucked, it loses 0.4% of thorium and 90% of its dangerous daughters to the body. Three-quarters of the thorium that has penetrated the body accumulates in the skeleton. Absorption through the skin is possible, but is not a likely means of exposure. Thorium's low solubility in water also means that excretion of thorium by the kidneys and faeces is rather slow. Tests on the thorium uptake of workers involved in monazite processing showed thorium levels above recommended limits in their bodies, but no adverse effects on health were found at those moderately low concentrations. No chemical toxicity has yet been observed in the tracheobronchial tract and the lungs from exposure to thorium. People who work with thorium compounds are at a risk of dermatitis. It can take as much as thirty years after the ingestion of thorium for symptoms to manifest themselves. Thorium has no known biological role. However, a study by Tonietti et al. showed that some microorganisms can mobilize thorium through bioleaching processes.
According to UN Human Rights Chief Volker Türk, the "reckless" war is disproportionately impacting civilians in the Middle East and beyond. 138,000 civilian sites in Iran were damaged during the conflict, with estimated time of reconstruction being 2-5 years. As the US and Israel executed joint strikes targeting Iranian military and institutional targets, Iran's capital reportedly became a ghost town, as civilians feared going outside or to their daily jobs. Reports have emerged that prisoners in Evin Prison have been receiving limited bread and water since the onset of the war. After the strikes, schools were ordered closed while banks and government offices remained in operation at reduced capacity. Local media reported that subway and bus services would remain operational. During the "near total" internet blackout in Iran, NetBlocks reported that internet connectivity dropped to 4% of ordinary levels. As the internet blackout exceeded 240 hours, making it the second longest ever, the government started handing out "white sim cards", which bypass filters, to government supporters, to allow them to promote its messaging. As news of Khamenei's death broke, security forces were deployed to prevent an uprising, with footage showing them opening fire on celebrants in the streets and shooting at people chanting behind the windows of their homes. During the first two weeks of March 2026, over 70,000 Afghan refugees returned to Afghanistan, frequently under forced circumstances, exacerbating the country's severe humanitarian crisis.
Sources: en.wikipedia.org
Cardarine is a common name for GW501516, a synthetic PPARδ agonist developed for research. It has not been approved as a medication in any country. It is classified as an unapproved drug and a prohibited substance in sport.
No. Cardarine is not an anabolic steroid; it belongs to a different chemical class that targets PPARδ. Steroids act primarily through androgen receptors, while cardarine acts through a nuclear receptor involved in metabolism.
Some rodent studies reported increased endurance and changes in fat metabolism after cardarine exposure. Long-term studies in animals also raised concerns about cancer in certain tissues. Human trial data are limited, so these findings cannot be directly translated to people.
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.