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.
Updated 2025-11-08. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Visual description for typical solid reference material. |
| Solubility | Poorly soluble in water; soluble in DMSO | Solubility depends on solvent, purity, and form. |
| Storage | Cool, dry, protected from light | Long-term storage often uses low temperature and desiccant. |
| Common analytical method | LC-MS/MS | Used for detection and quantification in biological matrices. |
| Common synonyms | GW-501516; GW501516; endurobol | Naming varies among literature, vendors, and databases. |
Regulatory bodies treat GW501516 as a prohibited substance in competitive sport. The World Anti-Doping Agency added it to the prohibited list, and it falls under classes covering metabolic modulators and hormone-related agents. It is not approved by drug regulators for human use, and it is not a lawful dietary supplement. Products sold under the cardarine name may contain unlisted ingredients or different compounds. Because no approved product exists, quality and identity are not guaranteed by pharmaceutical manufacturing standards.
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.
Regulatory treatment of cardarine differs by context and jurisdiction. In competitive sport, the World Anti-Doping Agency lists PPARδ agonists, including GW501516, as prohibited at all times. Outside sport, it lacks approval as a prescription medicine in major drug markets, and products sold for human consumption may be treated as unapproved drugs. Some countries also restrict importation or sale through general consumer protection and medicines laws. These classifications affect availability, testing, and legal risk without establishing therapeutic value.
Because cardarine is not an approved medicine, no pharmacopeial monograph defines its identity, purity, or storage requirements. Laboratories typically rely on in-house methods and reference standards when testing materials labeled as GW501516. Certificates of analysis may report purity and identity for a specific batch, but their scope varies and they do not guarantee safety or legal status. Independent verification can include high-performance liquid chromatography, mass spectrometry, nuclear magnetic resonance, and elemental analysis. The distinction between research chemical labeling and human use is significant because quality standards and oversight differ.
Pickled tofu (豆腐乳 in Chinese, pinyin: dòufurǔ, or 腐乳 fŭrŭ; chao in Vietnamese), also called "preserved tofu" or "fermented tofu", consists of cubes of dried tofu that have been allowed to fully air dry under hay and slowly ferment with the help of aerial bacteria. The dry fermented tofu is then soaked in salt water, Chinese rice wine, vinegar or minced chili peppers, or in a mixture of whole rice, bean paste, and soybeans. In the case of red pickled tofu (紅豆腐乳 in Chinese, Pinyin: hóng dòufurǔ), red yeast rice (cultivated with Monascus purpureus) is added for color. In Japan, pickled tofu with miso paste is called tofu no misodzuke, and is a traditional preserved food in Kumamoto. In the Ryukyu Islands, pickled and fermented tofu is called tōfuyō (豆腐餻). It is made from Shima-dōfu (an Okinawan variety of large and firm tofu). It is fermented and matured with koji mold, red koji mold, and awamori. Stinky tofu (臭豆腐 in Chinese, Pinyin: chòudòufu) is soft tofu that has been fermented in a vegetable and fish brine. The blocks of tofu have a pungent cheese smell, sometimes resembling rotting food. Despite its strong odor, the flavor and texture of stinky tofu is appreciated by aficionados, who describe it as delightful. The texture of this tofu is similar to the soft East Asian tofu from which it is made. The rind that stinky tofu develops when fried is said to be best when especially crisp, and fried stinky tofu is usually served with soy sauce, sweet sauce, or hot sauce.
== Lawrence Livermore Laboratory == In 1957, as a captain in the United States Air Force, Robert Finnigan joined the University of California Radiation Laboratory at Livermore (later the Lawrence Livermore National Laboratory). Finnigan worked on Project Pluto, a United States government program to develop nuclear powered ramjet engines for the Supersonic Low Altitude Missile (SLAM), a type of cruise missile. Finnigan led the group that developed computer control systems for the nuclear reactor that powered the missile. In 1959, Finnigan had the choice of rotating to a different tour of duty in the Air Force, or resigning from the Air Force and staying at Livermore. He remained at Livermore for two more years. Finnigan's group developed the Tory II-A prototype and Tory II-C reactor and controls, which were tested at the Nevada Test Site in the 1960s.
Triiodothyronine, also known as T3, is a thyroid hormone. It affects almost every physiological process in the body, including growth and development, metabolism, body temperature, and heart rate. Production of T3 and its prohormone thyroxine (T4) is activated by thyroid-stimulating hormone (TSH), which is released from the anterior pituitary gland. This pathway is part of a closed-loop feedback process: Elevated concentrations of T3, and T4 in the blood plasma inhibit the production of TSH in the anterior pituitary gland. As concentrations of these hormones decrease, the anterior pituitary gland increases production of TSH, and by these processes, a feedback control system stabilizes the level of thyroid hormones in the bloodstream. At the cellular level, T3 is the body's more active and potent thyroid hormone. T3 helps deliver oxygen and energy to all of the body's cells, its effects on target tissues being roughly four times more potent than those of T4. Of the thyroid hormone that is produced, just about 20% is T3, whereas 80% is produced as T4. Roughly 85% of the circulating T3 is later formed in the liver and anterior pituitary by removal of the iodine atom from the carbon atom number five of the outer ring of T4. In any case, the concentration of T3 in the human blood plasma is about one-fortieth that of T4. The half-life of T3 is about 2.5 days. The half-life of T4 is about 6.5 days. T3 levels start to rise 45 minutes after administration and peak at about 2.5 hours.
=== Availability === Ketoconazole is available widely throughout the world. In 2013, the European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) recommended that a ban be imposed on the use of oral ketoconazole for systemic use in humans throughout the European Union, after concluding that the risk of serious liver injury from systemic ketoconazole outweighs its benefits.
Sources: en.wikipedia.org
== Research in cancer == Deoxycholate and other secondary bile acids cause DNA damage. Secondary bile acids increase intracellular production of reactive oxygen and reactive nitrogen species resulting in increased oxidative stress and DNA damage. As shown in the figure below, deoxycholate added to the diet of mice increased the level of 8-oxo-dG, an oxidative DNA damage, in the colonic epithelium of mice. When the level of deoxycholate-induced DNA damage is high, DNA repair enzymes that ordinarily reverse DNA damage may not be able to keep up. DNA damage has frequently been proposed as a major cause of cancer. DNA damage can give rise to cancer by causing mutations. When deoxycholate was added to the food of mice so that their feces contained deoxycholate at about the same level present in feces of human on a high fat diet, 45% to 56% of the mice developed colon cancer over the next 10 months, while none of the mice on a diet without deoxycholate developed cancer. Thus, exposure of the colon to deoxycholate may cause cancer in mice. However, this same study reported that, when chlorogenic acid was added to the diet alongside deoxycholate, only 18% of the mice developed colon cancer. Chlorogenic acid is a component of common foods and beverages; coffee contains an average of 53.8 mg chlorogenic acid per 100 mL. Therefore, to consume the level of chlorogenic acid used in the study, a human on a "standard" 2000-calorie daily diet (416 g/d; 250 g carbs, 100 g protein, 66 g fat) would need to consume roughly 55 mL of coffee each day, or just under 2 fluid ounces.
== Mechanism of action == Moxonidine is a selective agonist at the imidazoline receptor subtype 1 (I1). This receptor subtype is found in both the rostral ventro-lateral pressor and ventromedial depressor areas of the medulla oblongata. Moxonidine therefore causes a decrease in sympathetic nervous system activity and, therefore, a decrease in blood pressure. Compared to the older central-acting antihypertensives, moxonidine binds with much greater affinity to the imidazoline I1-receptor than to the α2-receptor. In contrast, clonidine binds to both receptors with near equal affinity. Moxonidine has an affinity for I1 that is 33 times greater than α2, compared to clonidine which is only four times greater. In addition, moxonidine may also promote sodium excretion, improve insulin resistance and glucose tolerance and protect against hypertensive target organ damage, such as kidney disease and cardiac hypertrophy.
CAM plants, such as cacti and succulent plants, also use the enzyme PEP carboxylase to capture carbon dioxide, but only at night. Crassulacean acid metabolism allows plants to conduct most of their gas exchange in the cooler night-time air, sequestering carbon in 4-carbon sugars which can be released to the photosynthesizing cells during the day. This allows CAM plants to minimize water loss (transpiration) by maintaining closed stomata during the day. CAM plants usually display other water-saving characteristics, such as thick cuticles, stomata with small apertures, and typically lose around 1/3 of the amount of water per CO2 fixed.
=== First measures === Right after taking office on 1 January 2023, Lula and his ministers took several measures to revert Bolsonaro policies and/or create policies announced during the election campaign and the transition of power. This processs, known as "desbolsonarização" (de-'Bolsonarization') or "revogaço" (mass repeal of decrees) by some ministers and party members included a series of federal decrees revoking the previous government's measures involving weapons, environment policies and top officials' data secrecy. Some of the decrees included temporarily suspending new authorizations for shooting clubs, revoking Bolsonaro government policies that allowed "artisan mining" in the Amazon rainforest area and indigenous lands (which were seen as an incentive to illegal miners). and the creation of the "Secretary of Digital Policies", which was to be established under the Secretary of Social Communications with the stated objective of "combatting the spread of disinformation, fake news and hate speech on the internet". On the same week, Environment and Climate Change Minister Marina Silva claimed that another "revogaço" was yet to come. Mostly related to the teto de gastos (debt ceiling) fiscal policy, which was seen as impractical by government officials. This policy was later replaced with another debt limit law following its approval in the Federal Congress.
== Binding and activation == Ligand binding is an equilibrium process. Ligands bind to receptors and dissociate from them according to the law of mass action in the following equation, for a ligand L and receptor, R. The brackets around chemical species denote their concentrations.
Sources: en.wikipedia.org
Cardarine targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not bind the androgen receptor in the way SARMs do.
Most methods use liquid chromatography with tandem mass spectrometry. Urine is common in anti-doping testing, and blood or plasma may be used in research.
Typical guidance is cool, dry, dark storage, often at low temperature and with desiccant. Stability data are limited, so storage conditions should be verified for each batch or supplier.
Cardarine is a common name for the investigational compound GW501516. It acts as a PPARδ agonist and is not approved for human use. It is prohibited in sport.