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 2026-07-20. 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.
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.
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.
| 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. |
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.
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.
=== Other elements === Not all elements which are found in the human body in trace quantities play a role in life. Some of these elements are thought to be simple common contaminants without function (examples: caesium, titanium), while many others are thought to be active toxins, depending on amount (cadmium, mercury, lead, radioactives). In humans, arsenic is toxic, and its levels in foods and dietary supplements are closely monitored to reduce or eliminate its intake. Some elements (silicon, boron, nickel, vanadium) are probably needed by mammals also, but in far smaller doses. Bromine is used by some (though not all) bacteria, fungi, diatoms, and seaweeds, and opportunistically in eosinophils in humans. One study has indicated bromine to be necessary to collagen IV synthesis in humans. Fluorine is used by a number of plants to manufacture toxins but in humans its only known function is as a local topical hardening agent in tooth enamel.
Life-threatening overdose of opium tincture owes to the preparation's morphine content. Morphine produces a dose-dependent depressive effect on the respiratory system, which can lead to profound respiratory depression, hypoxia, coma and finally respiratory arrest and death. If overdose of opium tincture is suspected, rapid professional intervention is required. The primary concern is re-establishing a viable airway and institution of assisted or controlled ventilation if the patient is unable to breathe on their own. Other supportive measures such as the use of vasopressors and oxygen may be indicated to treat cardiac and/or pulmonary failure. Cardiac arrhythmias or arrest will require advanced life-saving measures. Intravenous naloxone or nalmefene, quick-acting opioid antagonists, are the first-line treatment to reverse respiratory depression caused by an overdose of opium tincture. Gastric lavage may be of some use in certain cases.
=== Shooting of student at law school === Duterte stated at a rally in April 2016 that he shot a fellow student who had bullied him about his Visayan origin as well as other students of the same ethnicity, while at San Beda law college. He said, "But the truth is, I'm used to shooting people. When we were about to graduate from San Beda, I shot a person." Duterte said that he shot the student in a corridor at the college when the said student called him names again. He later told a reporter that the student survived, but refused to answer any further questions about the incident. However, in an interview aired on 24 Oras and published on the official GMA News Online website on April 22, 2016, retired labor arbiter Arthur Amansec said Duterte and Octavio Goco at that time were both playing with a gun as it was normal for students to bring guns to school in the seventies. Amansec is Duterte's former classmate in San Beda College who witnessed the incident. He added that "the bullet hit the school's wooden floor and was embedded there." Amansec emphasized that Duterte and Goco remained friends until Goco died in the United States years later.
Sources: en.wikipedia.org
Things escalated in March 2025 when Ye expressed that he disliked Pusha T commenting on his political views, and then again in April when he targeted Pusha T in a livestreamed rant: "Pusha T, all that tough guy shit. Where the tough guy shit?" Pusha T responded on Let God Sort Em Out's lead single "Ace Trumpets", mentioning West and seemingly rapping that his comments were merely amusing. West responded, admitting that he missed the friendship. Pusha T would go on to claim in interviews that he does not think West is a real man and stating: "Outside of music, we're nothing. Outside of that, his principles, his morals, his mind-set—we don't see eye-to-eye hardly ever and we never have." Pusha T took aim at rapper and GOOD Music in-house producer Travis Scott in the lyrics of promotional single "So Be It". The animosity stems primarily from 2023, when Clipse and Williams were working on Let God Sort Em Out in Paris. Travis Scott traveled to the studio to play them his upcoming album Utopia (2023). Missing from this album-listening session was Drake's finalized guest verse on the track "Meltdown", in which he makes a reference to buying Williams's jewelry and melting it down. Pusha T recalled the moment: "He sees me [and Malice] there. He's like, 'Oh, man, everybody's here,' he's smiling, laughing, jumping around, doing his fucking monkey dance. We weren't into the music, but he wanted to play it, wanted to film [us and Williams listening to it]. And then a week later you hear 'Meltdown,' which he didn’t play.
Five amino acids possess a charge at neutral pH. Often these side chains appear at the surfaces on proteins to enable their solubility in water, and side chains with opposite charges form important electrostatic contacts called salt bridges that maintain structures within a single protein or between interfacing proteins. Many proteins bind metal into their structures specifically, and these interactions are commonly mediated by charged side chains such as aspartate, glutamate and histidine. Under certain conditions, each ion-forming group can be charged, forming double salts. The two negatively charged amino acids at neutral pH are aspartate (Asp, D) and glutamate (Glu, E). The anionic carboxylate groups behave as Brønsted bases in most circumstances. Enzymes in very low pH environments, like the aspartic protease pepsin in mammalian stomachs, may have catalytic aspartate or glutamate residues that act as Brønsted acids.
== Oxygen-18 == Oxygen-18 (18O, Ω) is one of the stable isotopes of oxygen, with roughly 0.20% abundance, and considered one of the environmental isotopes. Most 18O is produced when 14N (made abundant from CNO burning) captures a 4He nucleus, becoming 18F. This quickly (half-life around 110 minutes) beta decays to 18O making that isotope common in the helium-rich zones of stars. Temperatures on the order of 109 kelvins are needed to fuse oxygen into sulfur. Fluorine-18 is usually produced by irradiation of 18O-enriched water with high-energy (about 18 MeV) protons prepared in a cyclotron or a linear accelerator, yielding an aqueous solution containing 18F as fluoride ion. This solution is then used for rapid synthesis of a labeled molecule, often with the fluorine atom replacing a hydroxy group. The labeled molecules or radiopharmaceuticals have to be synthesized after the radiofluorine is prepared, as the high energy proton radiation would destroy the molecules. Large amounts of oxygen-18 enriched water are used in positron emission tomography centers, for on-site production of 18F-labeled fluorodeoxyglucose (FDG). Measurements of the 18O/16O ratio (known as δ18O) are often used in paleoclimatology. Water molecules with a lighter isotope are slightly more likely to evaporate and less likely to fall as precipitation, so Earth's freshwater and polar ice have slightly less (0.1981%) 18O than air (0.204%) or seawater (0.1995%). This disparity allows the study of historical temperature patterns via the analysis of ice cores.
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.
Legal status varies by country, but cardarine is not approved as a medicine in major jurisdictions. It is often sold as a research chemical, a category that may not be lawful for human use. Buyers should check local laws and product labels carefully.