Everything below concerns PPARδ agonist. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-06-25. Where a claim depends on a specific study, the study is described rather than over-claimed.
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 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.
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.
Safety discussions about cardarine frequently cite rodent carcinogenicity findings reported in the 2000s. In those studies, treated animals developed tumors at multiple sites, leading sponsors to discontinue clinical development. The relevance of these findings to humans has not been resolved, but they are a major reason the compound is not approved. Current literature emphasizes uncertainty about long-term effects and the risks of unregulated use. Regulators and health agencies have not established a safe human exposure level.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular target | PPAR delta (NR1C2) | Ligand-activated nuclear receptor. |
| Primary tissues studied | Skeletal muscle, liver, adipose | Effects on fatty acid oxidation and energy use. |
| Typical detection matrix | Urine | Used in anti-doping analysis. |
| Common analytical method | LC-MS/MS | Detects parent compound and metabolites. |
| Sport regulatory class | Prohibited at all times | Listed as a metabolic modulator by WADA. |
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.
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.
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 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.
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.
However, the binary process happens merely because it is the most probable. In anywhere from two to four fissions per 1000 in a nuclear reactor, ternary fission can produce three positively charged fragments (plus neutrons) and the smallest of these may range from so small a charge and mass as a proton (Z = 1), to as large a fragment as argon (Z = 18). The most common small fragments, however, are composed of 90% helium-4 nuclei with more energy than alpha particles from alpha decay (so-called "long range alphas" at ~16 megaelectronvolts (MeV)), plus helium-6 nuclei, and tritons (the nuclei of tritium). Though less common than binary fission, it still produces significant helium-4 and tritium gas buildup in the fuel rods of modern nuclear reactors. Bohr and Wheeler used their liquid drop model, the packing fraction curve of Arthur Jeffrey Dempster, and Eugene Feenberg's estimates of nucleus radius and surface tension, to estimate the mass differences of parent and daughters in fission. They then equated this mass difference to energy using Einstein's mass-energy equivalence formula. The stimulation of the nucleus after neutron bombardment was analogous to the vibrations of a liquid drop, with surface tension and the Coulomb force in opposition. Plotting the sum of these two energies as a function of elongated shape, they determined the resultant energy surface had a saddle shape. The saddle provided an energy barrier called the critical energy barrier.
=== Transitional phases === Transitional phases at the onset or departure of El Niño or La Niña can also be important factors on global weather by affecting teleconnections. Significant episodes, known as Trans-Niño, are measured by the Trans-Niño index (TNI). Examples of affected short-time climate in North America include precipitation in the Northwest US and intense tornado activity in the contiguous US.
As anti-angiogenic cancer therapies have achieved widespread use, there has been increased interest in non-invasive monitoring of angiogenesis. One of the most extensively examined targets of angiogenesis is integrin αVβ3. Radiolabeled peptides containing RGD show high affinity and selectivity for integrin αVβ3 and are being investigated as tools to monitor treatment response of tumors via PET imaging. These include 18F-Galacto-RGD, 18F-Fluciclatide-RGD, 18F-RGD-K5, 68Ga-NOTA-RGD, 68Ga-NOTA-PRGD2, 18F-Alfatide, 18F-Alfatide II, and 18F-FPPRGD2. In a meta-analysis of studies using PET/CT in patients with cancer, it was shown that this diagnostic method may be very useful for detecting malignancies and predicting short-term outcomes, although larger-scale studies are needed.
== Production == Small amounts of fission products are naturally formed as the result of either spontaneous fission of natural uranium, which occurs at a low rate, or as a result of neutrons from radioactive decay or reactions with cosmic ray particles. The microscopic tracks left by these fission products in some natural minerals (mainly apatite and zircon) are used in fission track dating to provide the cooling (crystallization) ages of natural rocks. The technique has an effective dating range of 0.1 Ma to >1.0 Ga depending on the mineral used and the concentration of uranium in that mineral. About 1.5 billion years ago in a uranium ore body in Africa, a natural nuclear fission reactor operated for a few hundred thousand years and produced approximately 5 tonnes of fission products. These fission products were important in providing proof that the natural reactor had occurred. Fission products are produced in nuclear weapon explosions, with the amount depending on the type of weapon. The largest source of fission products is from nuclear reactors. In current nuclear power reactors, about 3% of the uranium in the fuel is converted into fission products as a by-product of energy generation. Most of these fission products remain in the fuel unless there is fuel element failure or a nuclear accident, or the fuel is reprocessed.
Sources: en.wikipedia.org
=== 2010-2013 === A book A Little War That Shook the World by Ronald Asmus was published in January 2010. One staff worker for Dick Cheney is quoted as expressing concern that American president George W. Bush had probably given Putin a "green light" to start hostilities against Georgia during the April 2008 meeting in Sochi. The book reported that French president Sarkozy said that he was ready to confront Russia on Georgia's NATO membership, but not German Chancellor Merkel. Germany's refusal to submit to the US proposal was a first time the US interests were neglected in the NATO and Putin used NATO's hesitation as an opportunity to wage the war against its neighbor. Asmus stated: "Many in the West tried to step back and pretend that the Russo-Georgian war was a local conflict they were not a party to." In October 2011, Dmitry Rogozin said in an interview with Echo of Moscow that Russia achieved that Ukraine and Georgia did not become NATO members and Russia gained respect. In 2011, Condoleezza Rice, former Secretary of State, published her memoirs where she wrote that she had told Saakashvili before the war not to respond to Russia because nobody would help him. She told The Weekly Standard that "But in no way were the Georgians at fault..." She said: "They were doing all kinds of things to try to provoke the Georgians. The shelling of Georgian cities by the South Ossetians, Russian allies, is clearly what started the war." Rice also talked about Russian hatred for Georgians.
"Validation. The assurance that a product, service, or system meets the needs of the customer and other identified stakeholders. It often involves acceptance and suitability with external customers. Contrast with verification." "Verification. The evaluation of whether or not a product, service, or system complies with a regulation, requirement, specification, or imposed condition. It is often an internal process. Contrast with validation." Similarly, for a Medical device, the FDA (21 CFR) defines Validation and Verification as procedures that ensures that the device fulfil their intended purpose.
A dipeptide is an organic compound derived from two amino acids. The constituent amino acids can be the same or different. When different, two isomers of the dipeptide are possible, depending on the sequence. Several dipeptides are physiologically important, and some are both physiologically and commercially significant. A well known dipeptide is aspartame, an artificial sweetener.
The cords are weakened through the injection of small amounts of the enzyme collagenase, which breaks peptide bonds in collagen. Clostridial collagenase injections have been found to be more effective than placebo. In February 2010 the US Food and Drug Administration (FDA) approved injectable collagenase extracted from Clostridium histolyticum for the treatment of Dupuytren's contracture in adults with a palpable Dupuytren's cord. (Three years later, it was approved as well for the treatment of the sometimes related Peyronie's disease.) In 2011 its use for the treatment of Dupuytren's contracture was approved as well by the European Medicines Agency, and it received similar approval in Australia in 2013. However, the Swedish manufacturer withdrew distribution of this drug in Europe including the UK, Australia, and Asia in March 2020. (It is also used in the US as a dermatological treatment for cellulite aka "cottage cheese thighs"). The treatment with collagenase is different for the MCP joint and the PIP joint. In a MCP joint contracture the needle must be placed at the point of maximum bowstringing of the palpable cord. The needle is placed vertically on the bowstring. The collagenase is distributed across three injection points. For the PIP joint the needle must be placed not more than 4 mm distal to palmar digital crease at 2–3 mm depth. The injection for PIP consists of one injection filled with 0.58 mg CCH 0.20 ml. The needle must be placed horizontal to the cord and also uses a three-point distribution.
This discovery of an animal experimental model for scurvy, which was made even before the essential idea of "vitamins" in foods had been put forward, has been called the single most important piece of vitamin C research. In 1915, New Zealand troops in the Gallipoli Campaign had a lack of vitamin C in their diet which caused many of the soldiers to contract scurvy. Vilhjalmur Stefansson, an Arctic explorer who had lived among the Inuit, proved that the all-meat diet they consumed did not lead to vitamin deficiencies. He participated in a study in New York's Bellevue Hospital in February 1928, where he and a companion ate only meat for a year while under close medical observation, yet remained in good health. In 1927, Hungarian biochemist Albert Szent-Györgyi isolated a compound he called "hexuronic acid". Szent-Györgyi suspected hexuronic acid, which he had isolated from adrenal glands, to be the antiscorbutic agent, but he could not prove it without an animal-deficiency model. In 1932, the connection between hexuronic acid and scurvy was finally proven by American researcher Charles Glen King of the University of Pittsburgh. King's laboratory was given some hexuronic acid by Szent-Györgyi and soon established that it was the sought-after anti-scorbutic agent. Because of this, hexuronic acid was subsequently renamed ascorbic acid.
Sources: en.wikipedia.org
It binds to and activates PPAR delta, a nuclear receptor that controls expression of genes related to fatty acid oxidation. This mechanism can alter energy metabolism in animal models. It is not a direct stimulant or fat-burning enzyme.
Early-stage trials examined lipid and glucose markers, but the development program was discontinued. Published human results are limited and do not support approved use for any indication. Claims of performance or health benefits remain unproven.
Yes. Laboratories use LC-MS/MS to detect GW501516 and its metabolites in urine. Detection depends on timing and sensitivity, but the substance is banned at all times.
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.