GW501516 comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-12-18. 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.
Cardarine is not approved for human therapeutic use in any major jurisdiction. It appears on the World Anti-Doping Agency Prohibited List as a PPARδ agonist within the hormone and metabolic modulators category. Sports organizations test for it because it has been detected in athlete samples and seized products. Regulatory actions against marketed research chemical versions have occurred in several countries, though enforcement varies. Availability through unregulated channels complicates oversight.
Analytical laboratories typically identify cardarine and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is a common matrix in anti-doping testing, while blood and tissue may be used in research settings. Detection windows depend on the assay, the sample matrix, and the compound's metabolism. Because cardarine is extensively metabolized, laboratories often target specific metabolites to improve sensitivity and confirmation. Reference standards are required for reliable quantification. Method validation includes checks for selectivity, linearity, and carryover.
| 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 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.
At the molecular level, GW501516 binds and activates PPARδ, a nuclear receptor that regulates transcription. Activation shifts expression of genes involved in fatty acid oxidation, energy expenditure, and lipid transport in skeletal muscle and liver. Animal studies report increased endurance and altered lipid profiles after exposure. Human data are limited to small trials and do not establish long-term safety or efficacy. PPARδ also has roles in cell proliferation, so the relationship between activation and cancer risk remains an open question.
Published literature on cardarine includes in vitro assays, rodent experiments, and a small number of human studies. Reports describe effects on exercise capacity and lipid metabolism in animals, while human evidence is sparse. Many online descriptions present the compound as a proven endurance aid, a claim not supported by regulatory approval or large clinical trials. Analytical studies focus on identifying the parent compound and its metabolites in biological samples. Important uncertainties include species differences, dose-response relationships, and the relevance of rodent tumor findings to humans.
=== Hierarchical structure === While the secondary structures are determined by energy state and hydrogen bonds formed between amino acids, hierarchical structures are determined by the hydrophobicity of the peptide. Exon 1 encoded peptide is mainly hydrophilic, and is more extended when immersed in water. In contrast, exon 3 encoded peptide contains both hydrophobic and hydrophilic blocks, suggesting the formation of micelles, where the hydrophobic block will cluster on the inside with the hydrophilic portion surrounding it. Thus, a single complete resilin protein, when immersed in water, takes on the structure in which exon 1 encoded segment extends out from the micelle exon 3 encoded peptide forms. Once resilin is transferred to the outside of the cell, their exon 2 encoded peptides, the chitin binding segments, bind to chitin. Meanwhile, di- or tri-tyrosine crosslinking is formed by oxidative coupling, mediated by peroxidase, between tyrosine residuals. Like other elastomeric proteins, the degree of cross linking in resilin is low, which ensures the low stiffness and high resilience. Cross linked peptides encoded by exon 1 have a resilience greater than 93%, while that encoded by exon 3 has a resilience of 86%. In addition, natural resilin has a resilience of 92%, similar to that of exon 1, suggesting again that exon 1 may play a more important role in the elastic property of resilin.
== Epidemiology == Coronary artery disease is the leading cause of death in men and women. This condition is the cause of one third of all deaths, which is especially worse in areas with lower socioeconomic status. Mortality is nearly five times higher in men than women, but mortality difference narrows with age. Black women are more likely than white women to have a heart attack. Black adults have a higher mortality rate than white adults from heart attack. Asian adults have the least incidence of coronary artery disease. Asian Indian men, Filipino men and Filipino women have a higher risk than white people. Young Hispanic women who have a heart attack have a higher mortality rate than young Hispanic men. They have a higher mortality rate than young Black adults and young white adults.
=== Polymerization === The polymer formed by linking thiophene through its 2,5 positions is called polythiophene. Polymerization is conducted by oxidation using electrochemical methods (electropolymerization) or electron-transfer reagents. An idealized equation is shown:
Sources: en.wikipedia.org
==== Hair clippers ==== Sharp hair clippers are used to shave the animal and expose its bare skin. Close contact between brand and bare skin is much more important in freeze branding than in hot branding. This is due to hair's excellent heat insulation, which can drastically reduce heat flux during cryogenic branding. An animal not being shaved closely enough is the main cause of failed brands.
An estimated 3.9 million tonnes (t) of nickel per year are mined worldwide; Indonesia (2,600,000 t), the Philippines (270,000 t), Russia (200,000 t), Canada (140,000 t), New Caledonia (140,000 t), and China (120,000 t) are the largest producers as of 2025. The largest nickel deposits in non-Russian Europe are in Finland and Greece. Identified land-based sources averaging at least 1% nickel contain at least 130 million tonnes of nickel. About 60% is in laterites and 40% is in sulfide deposits. Also, extensive nickel sources are found in the depths of the Pacific Ocean, especially in an area called the Clarion Clipperton Zone in the form of polymetallic nodules peppering the seafloor at 3.5–6 km below sea level. These nodules are composed of numerous rare-earth metals and are estimated to be 1.7% nickel. With advances in science and engineering, regulation is currently being set in place by the International Seabed Authority to ensure that these nodules are collected in an environmentally conscientious manner while adhering to the United Nations Sustainable Development Goals. The one place in the United States where nickel has been profitably mined is Riddle, Oregon, with several square miles of nickel-bearing garnierite surface deposits. The mine closed in 1987. The Eagle mine project is a new nickel mine in Michigan's Upper Peninsula. Construction was completed in 2013, and operations began in the third quarter of 2014. In the first full year of operation, the Eagle Mine produced 18,000 t. The Eagle mine produced 17,000 tons of nickel concentrate in 2023.
Meinrad Busslinger (born 30 July 1952) is a biochemist and immunologist, renown for his work on B cells. He is a Senior Scientist and Scientific Deputy Director of the Research Institute of Molecular Pathology (IMP) in Vienna, Austria.
Sources: en.wikipedia.org
== External links == "P2Y Receptors: P2Y4". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Archived from the original on 2016-03-03. Retrieved 2008-12-09. This article incorporates text from the United States National Library of Medicine, which is in the public domain.
Tetrahydrobiopterin (branded as Kuvan) (sapropterin dihydrochloride), a small molecule drug for phenylketonuria, introduced in 2007 as the first medication-based intervention to treat phenylketonuria Arylsulfatase B (branded as Naglazyme) (galsulfase), a recombinant protein therapeutic for Maroteaux–Lamy syndrome (also called mucopolysaccharidosis type VI) Iduronidase (branded as Aldurazyme), a recombinant protein therapeutic for mucopolysaccharidosis I Amifampridine (branded as Firdapse), a small molecule drug for Lambert–Eaton myasthenic syndrome (as of 2013 approved in the EU only) Elosulfase alfa (branded as Vimizim), is the only enzyme replacement therapy to address the cause of Morquio A Syndrome (MPS IVA), which affects an estimated 3,000 patients in the developed world. The disease occurs as a result of a deficiency of activity in an enzyme involved in glycosaminoglycan (GAG) metabolism. Cerliponase alfa (branded as Brineura), is an enzyme replacement treatment for Batten disease, which is a form of neuronal ceroid lipofuscinosis. It was approved in 2017. Valoctocogene roxaparvovec (branded as Roctavian) is an adeno-associated viral vector for treatment of hemophilia A that aims to transfer a working copy of the Factor VIII gene into patients who lack one. It was approved in the EU in August 2022. Biomarin is working to develop several new drugs.
== House of Este == In 1452 Holy Roman Emperor Frederick III offered the duchy to Borso d'Este, whose family had ruled the city of Modena and nearby Reggio Emilia for centuries. Borso in 1450 had also succeeded his brother as margrave in the adjacent Papal Duchy of Ferrara, where he received the ducal title in 1471. The Este lands on the southern border of the Holy Roman Empire with the Papal States formed a stabilizing buffer state in the interest of both.
WALP peptides are a class of synthesized, membrane-spanning α-helices composed of tryptophan (W), alanine (A), and leucine (L) amino acids. They are designed to study properties of proteins in lipid membranes such as orientation, extent of insertion, and hydrophobic mismatch.
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.
No. Cardarine has not received approval for human therapeutic use in major jurisdictions. It remains an investigational compound.