If you have been reading about PPARδ agonist and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-06-05. Numbers and descriptions here follow the published literature rather than marketing material.
Cardarine is frequently described as a fat-burning or endurance-enhancing supplement, but these claims exceed the available evidence. The compound is not a hormone, steroid, or selective androgen receptor modulator. Research articles discuss it as a tool compound for studying PPARδ biology, while anti-doping literature focuses on its abuse and detection. Quality of unapproved products is uncertain, and independent analyses have found impurities or incorrect labeling. Open questions include whether human cancer risk resembles that seen in rodents and how often non-athletes use the substance.
Cardarine has no approved therapeutic indication and is not marketed as a medicine. The World Anti-Doping Agency lists GW501516 as a prohibited substance at all times, covering both in-competition and out-of-competition periods. National laws vary: some countries treat it as an unapproved drug subject to import controls, while others have specific restrictions on sale for human consumption. It is often sold as a research chemical, a label that does not imply safety or legality. Enforcement actions have targeted online vendors and shipments.
Anti-doping laboratories identify GW501516 and related metabolites using liquid chromatography coupled with tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be analyzed. The method targets the parent compound and phase I and phase II metabolites, which extend the detection window. Because the substance is prohibited at all times, athletes can be tested outside competition. Detection limits and windows depend on the assay, sample type, and individual metabolism.
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.
Cardarine is a common name for GW501516, a synthetic compound first described in the 1990s as a selective agonist of the peroxisome proliferator-activated receptor delta. It was studied in preclinical models for metabolic and cardiovascular conditions, but it has not been approved as a medicine in the United States, Europe, or other major jurisdictions. Retail products labeled as cardarine are generally research chemicals or supplements, not pharmaceutical formulations. Because human safety and efficacy data remain limited, regulatory agencies treat it as an unapproved substance rather than a therapeutic product.
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.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Prohibited in sport; not approved as medicine | Listed by WADA at all times. |
| Common synonyms | GW501516, GW-501516, endurobol | Cardarine is a colloquial name. |
| Typical analytical method | LC-MS/MS | Detects parent compound and metabolites. |
| Common test matrix | Urine | Blood and dried blood spots also possible. |
| Legal classification | Varies by country | Often treated as unapproved drug or research chemical. |
PPARδ is a nuclear receptor that influences transcription of genes involved in fatty acid oxidation, lipid transport, and energy homeostasis. GW501516 binds and activates this receptor with high selectivity relative to PPARα and PPARγ in laboratory assays. Activation alters expression of target genes in skeletal muscle, liver, and adipose tissue in animal models. The exact clinical consequences of these changes in humans remain incompletely characterized, and observed effects in animals do not establish therapeutic benefit or safety.
Published studies have examined GW501516 in animal models of obesity, insulin resistance, and exercise endurance. Early human trials reportedly ended, and development was discontinued after preclinical findings raised concerns about cancer in some rodent studies. Regulatory agencies have not approved cardarine for any medical use. Its availability through non-pharmaceutical channels raises questions about identity, purity, and legal status that are separate from its laboratory pharmacology. Those questions are often addressed through analytical testing rather than assumptions about product labels.
Cardarine is a common name for GW501516, also GW-1516, a synthetic compound developed as a peroxisome proliferator-activated receptor delta (PPARδ) agonist. It belongs to a class of agents that modulate gene transcription related to lipid and energy metabolism. The compound was studied in preclinical and early clinical research for metabolic and cardiovascular conditions, but it did not progress to approved therapeutic use. Its name appears in fitness and sports contexts despite not being approved as a drug.
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.
Anti-doping laboratories detect GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be used in some programs. Detection depends on factors such as dose, timing, metabolism, and the sensitivity of the assay. Published methods describe limits of detection in the low nanogram per milliliter range for related compounds. Exact detection windows are not fixed for all situations and remain an area of ongoing study.
Products sold as cardarine have been found to contain incorrect compounds, variable amounts, or no active ingredient at all. Independent testing is required to verify identity and purity. Common analytical approaches include high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance for structural confirmation. These methods can distinguish GW501516 from related PPAR agonists and from unrelated steroids. For regulators and researchers, such verification is central to interpreting both biological results and adverse event reports.
Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.
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.
==== Nasal inhalation ==== Inhalation by nose of a substance is almost identical to oral inhalation, except that some of the drug is absorbed intranasally instead of in the oral cavity before entering the airways. Both methods can result in varying levels of the substance to be deposited in their respective initial cavities, and the level of mucus in either of these cavities will reflect the amount of substance swallowed. The rate of inhalation will usually determine the amount of the substance which enters the lungs. Faster inhalation results in more rapid absorption because more substance finds the lungs. Substances in a form that resists absorption in the lung will likely resist absorption in the nasal passage, and the oral cavity, and are often even more resistant to absorption after they fail absorption in the former cavities and are swallowed.
=== Mass spectrometry === Mass spectrometry is a way to quantify RNA modifications. More often than not, modifications cause an increase in mass for a given nucleoside. This gives a characteristic readout for the nucleoside and the modified counterpart. Moreover, mass spectrometry allows the investigation of modification dynamics by labelling RNA molecules with stable (non-radioactive) heavy isotopes in vivo. Due to the defined mass increase of heavy isotope labeled nucleosides they can be distinguished from their respective unlabelled isotopomeres by mass spectrometry. This method, called NAIL-MS (nucleic acid isotope labelling coupled mass spectrometry), enables a variety of approaches to investigate RNA modification dynamics.
Dextromethorphan/bupropion, sold under the brand name Auvelity, is a combination medication for the treatment of major depressive disorder (MDD) and agitation associated with dementia due to Alzheimer's disease. Its active components are dextromethorphan (DXM) and bupropion. It is taken as a tablet by mouth. Side effects of dextromethorphan/bupropion include dizziness, headache, diarrhea, somnolence, dry mouth, sexual dysfunction, and hyperhidrosis, among others. The mechanism of action of dextromethorphan/bupropion in the treatment of depression is unknown. Dextromethorphan/bupropion was developed by Axsome Therapeutics and was approved for the treatment of major depressive disorder in the United States in August 2022.
== Overdose == There is limited experience with overdose of suvorexant. Suvorexant has been assessed in single doses of as high as 240 mg in clinical studies. The medication dose-dependently produces somnolence. High doses of suvorexant may also cause sleep-onset paralysis in some individuals (2% incidence at doses of 40–240 mg). Treatment of suvorexant overdose is based on symptoms and is supportive. Gastric lavage may be used where appropriate whereas the value of dialysis has not been determined. Because suvorexant has high plasma protein binding, hemodialysis is not expected to enhance elimination of suvorexant.
== Historical applications == By 2001, over 175 analytes had been measured using DBS, ranging from acylcarnitines and C-reactive protein to cyclosporine A, cytokines, hepatitis B virus, glucose, and antibodies for over 30 viruses and microorganisms. Other analytes included gentamicin, lipoproteins, prolactin, selenium, trace elements, vitamin A, and zinc protoporphyrin were also measured. In the 20th century, the use of blood and serum collected and dried on a filter paper for serologic testing for syphilis was already reported. Both field and home sample collections were described. The first report of blood absorbed onto filter paper for enzyme measurements was published in 1953. In 1962, Berry explored the use of filter paper urine samples for population-based screening programs. In 1980, an immunochemical test for colorectal cancer screening using fecal occult blood smears on specially treated filter paper was introduced. In 1987, successful extraction of DNA from blood collected on “blotter” paper and dried was first reported by McCabe. The United States can serve as one of the best examples of a widespread usage of DBS. There, DBS is a part nationally-coordinated effort (controlled by the American Center for Disease Control and Prevention) for newborn screening. This programme, named Newborn Screening Quality Assurance Program (NSQAP), ensures that newborns routinely undergo screening tests to detect those with diseases that need an increased medical attention. The NSQAP is based on dried blood spots sampling, where the blood is collected from the newborn's heel.
Sources: en.wikipedia.org
== Biological activity == Protolichesterinic acid exhibits diverse biological activities, including antimicrobial, enzyme inhibitory, and anticancer properties. Studies with the compound isolated from Usnea albopunctata have demonstrated broad-spectrum antimicrobial activity. It shows strong antibacterial effects against Klebsiella pneumoniae (minimum inhibitory concentration 0.25 μg/mL) and Vibrio cholerae (0.5 μg/mL), exceeding the potency of ciprofloxacin. The compound is also active against methicillin-resistant Staphylococcus aureus (MRSA) and shows notable antifungal activity against Trichophyton rubrum, surpassing amphotericin B in potency. As an inhibitor, protolichesterinic acid selectively targets 5-lipoxygenase while showing minimal effect on cyclooxygenase. This selective inhibition suggests potential applications in treating inflammatory conditions, particularly those involving leukotriene bronchoconstrictors. Structure-activity studies indicate that while the stereospecific side chain and exocyclic double bond are not essential for activity, the carboxylic acid group plays a crucial role. The compound also inhibits the DNA polymerase activity of human immunodeficiency virus-1 reverse transcriptase (HIV-1 RT). Research has revealed that protolichesterinic acid affects cancer cell metabolism by disrupting mitochondrial function through inhibition of oxidative phosphorylation and enhancement of glycolysis. The compound undergoes cellular processing via the mercapturic pathway, forming conjugates with glutathione.
Aspartic acid, for example, possesses one protonated amine and two deprotonated carboxyl groups, for a net charge of −1 at physiological pH. Fatty acids and fatty acid derivatives are another group of carboxylic acids that play a significant role in biology. These contain long hydrocarbon chains and a carboxylic acid group on one end. The cell membrane of nearly all organisms is primarily made up of a phospholipid bilayer, a micelle of hydrophobic fatty acid esters with polar, hydrophilic phosphate "head" groups. Membranes contain additional components, some of which can participate in acid–base reactions. In humans and many other animals, hydrochloric acid is a part of the gastric acid secreted within the stomach to help hydrolyze proteins and polysaccharides, as well as converting the inactive pro-enzyme, pepsinogen into the enzyme, pepsin. Some organisms produce acids for defense; for example, ants produce formic acid. Acid–base equilibrium plays a critical role in regulating mammalian breathing. Oxygen gas (O2) drives cellular respiration, the process by which animals release the chemical potential energy stored in food, producing carbon dioxide (CO2) as a byproduct. Oxygen and carbon dioxide are exchanged in the lungs, and the body responds to changing energy demands by adjusting the rate of ventilation. For example, during periods of exertion the body rapidly breaks down stored carbohydrates and fat, releasing CO2 into the blood stream. In aqueous solutions such as blood CO2 exists in equilibrium with carbonic acid and bicarbonate ion.
Applications of contact mechanics further extend into the micro- and nanotechnological realm. The original work in contact mechanics dates back to 1881 with the publication of the paper "On the contact of elastic solids" "Über die Berührung fester elastischer Körper" by Heinrich Hertz. Hertz attempted to understand how the optical properties of multiple, stacked lenses might change with the force holding them together. Hertzian contact stress refers to the localized stresses that develop as two curved surfaces come in contact and deform slightly under the imposed loads. This amount of deformation is dependent on the modulus of elasticity of the material in contact. It gives the contact stress as a function of the normal contact force, the radii of curvature of both bodies and the modulus of elasticity of both bodies. Hertzian contact stress forms the foundation for the equations for load bearing capabilities and fatigue life in bearings, gears, and any other bodies where two surfaces are in contact.
=== Clinical studies === Clinical trials suggest thymosin α1 may be useful in cystic fibrosis, septic shock, acute respiratory distress syndrome, peritonitis, pancreatitis, acute cytomegalovirus infection, TB, severe acute respiratory syndrome, and lung infections in critically ill patients., and for chronic hepatitis B. For hospitalized COVID-19 patients, a 2023 review concluded thymosin α1 was not effective in reducing mortality or length of hospitalization. A subsequent 2023 review contradicted this, showing a reduction in mortality but not length of stay. It has been studied for possible use in treating cancer (e.g. with chemotherapy).
Sources: en.wikipedia.org
Restricting the use of foamed polystyrene takeout food packaging is a priority of many solid waste environmental organisations. Efforts have been made to find alternatives to polystyrene, especially foam in restaurant settings. The original impetus was to eliminate chlorofluorocarbons (CFC), which was a former component of foam.
== Diagnosis == In terms of the diagnosis of Ullrich congenital muscular dystrophy upon inspection follicular hyperkeratosis, may be a dermatological indicator, additionally also serum creatine kinase may be mildly above normal. Other exams/methods to ascertain if the individual has Ullrich congenital muscular dystrophy are:
=== Exercise Therapy === Exercise based rehab is commonly used in the conservative management of tendinopathy. Strengthening exercises targeting the affected tendon, including eccentric, concentric, and isometric contractions, are frequently prescribed in clinical practice. Eccentric loading exercises, which involve muscle contraction while the muscle lengthens, are the most commonly used interventions for conditions such as patellar tendinopathy. A systematic review of randomized controlled trials involving individuals with chronic patellar tendinopathy found low- to very-low-quality evidence regarding the benefits of exercise compared with no treatment, glucocorticoid injections, or surgery. While exercise programs may reduce pain in some cases, studies have generally shown little or no difference in long-term function, pain outcomes, or return-to-sport rates when compared with other interventions.
Sources: en.wikipedia.org
Legal status varies by country. It is not approved as a medicine, and it is prohibited in sport. Some jurisdictions restrict import, sale, or possession.
Laboratories use liquid chromatography-tandem mass spectrometry to detect GW501516 and its metabolites. Urine is commonly tested, and testing can occur in and out of competition.
No, cardarine is not a SARM. It is a PPARδ agonist, which acts on a different receptor. The two classes are often confused in online discussions.
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.