PPARδ raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-03-22. Anything still debated is marked as such rather than presented as settled.
GW501516 acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in transcription of genes related to lipid handling and energy use. Activation of PPARδ can shift skeletal muscle toward greater fatty acid oxidation in animal models, which is one reason it drew interest for metabolic disease and exercise research. The exact downstream effects depend on tissue, species, dose, and duration. Human data are sparse, so many proposed benefits remain hypotheses rather than established clinical outcomes.
Laboratory studies have examined GW501516 in cell cultures and rodents for conditions such as dyslipidemia, insulin resistance, and obesity. Some trials in humans were initiated, but development was discontinued after preclinical findings raised concerns about cancer in certain models. Those findings do not prove that the compound causes cancer in people, but they contributed to regulatory caution. Later reviews often describe the evidence as preliminary and insufficient for assessing long-term safety.
In the fitness and bodybuilding literature, cardarine is frequently discussed as an endurance agent or fat-loss compound, although such claims are not supported by robust clinical evidence. Online descriptions often mix animal data, user anecdotes, and marketing language. Researchers who study PPARδ agonists distinguish between receptor activation in controlled experiments and unsupervised use of unverified products. The latter introduces unknown purity, dose, and interactions, making reported experiences difficult to interpret scientifically.
Regulatory treatment varies, but cardarine is not approved as a medicine. Sports authorities list GW501516 as a prohibited substance, and it is banned at all times under the World Anti-Doping Agency code. Many countries restrict sales for human consumption, while online vendors market it as a research chemical. Such products may lack purity data, and their actual contents can differ from the label. Purchasing or possessing cardarine may carry legal consequences depending on jurisdiction. The compound is not a dietary supplement ingredient in regulated markets.
Clinical development stopped after rodent studies showed tumors at multiple sites. Whether those findings predict human cancer risk remains an open question, but they led sponsors to discontinue programs. Human safety data are limited to small, short-term studies that were not designed to assess cancer risk. Reported effects in those studies included changes in blood lipids, but the evidence is insufficient for medical use. Long-term consequences of nonmedical use are not well characterized. Questions about dose, duration, and individual susceptibility remain unresolved.
| Property | Value | Notes |
|---|---|---|
| Solubility | Soluble in dimethyl sulfoxide and some organic solvents; practically insoluble in water | Solvent choice affects laboratory handling |
| Typical storage | -20 °C, desiccated, protected from light | Common condition for research samples |
| Analytical method | Liquid chromatography–tandem mass spectrometry (LC-MS/MS) | Used for identification and quantification in biological or product samples |
| Common synonyms | GW501516, GW-501516, GSK-516, Endurobol | Names found in research and anti-doping literature |
| Regulatory status | Unapproved therapeutic; prohibited in competitive sport | Status can vary by country and context |
Cardarine is explicitly prohibited by the World Anti-Doping Agency under the class of PPARδ agonists. Its presence in urine or blood samples can be detected using mass spectrometry-based methods, often liquid chromatography-tandem mass spectrometry. Athletes who test positive may face sanctions, including bans from competition. The compound is also regulated as a prescription-only or unapproved drug in many countries. Enforcement varies by jurisdiction, and some regions treat it as a controlled substance. Online sales may occur despite these restrictions, creating quality and legal risks.
Laboratory detection of cardarine typically involves sample preparation followed by chromatographic separation and mass spectrometric identification. Urine is the most common matrix for anti-doping tests, though blood and hair have also been explored. Methods can target the parent compound or its metabolites, depending on the expected window of detection. Reference standards are required for accurate quantification. Matrix effects and dilution can influence results, so laboratories use internal standards and validation protocols. The exact detection window varies with dose, route, and individual metabolism.
A common misconception is that cardarine has been proven safe for human use. In reality, human clinical data are limited, and long-term animal studies have raised concerns about cancer. Another misconception is that it is a supplement or vitamin-like compound. It is a synthetic research chemical with no approved medical indication. Scientific discussion often focuses on its mechanism and detection rather than therapeutic use. Regulatory and anti-doping literature treats it primarily as a prohibited substance.
Laboratory studies indicate that GW501516 activates PPARδ, a nuclear receptor involved in fatty acid oxidation and energy metabolism. In rodent experiments, treated animals often showed increased endurance and reduced fat mass. These effects were observed under controlled conditions and do not establish safe or effective use in humans. The exact dose-response relationship in humans remains poorly characterized. Species differences in metabolism can affect how results translate across animals and people.
Safety concerns emerged from long-term animal studies. In rodents given the compound for extended periods, researchers found an increased incidence of certain cancers, including liver and bladder tumors. These findings contributed to the discontinuation of clinical development. Whether similar risks apply to short-term or low-level exposure in humans is not established, and controlled human safety data are limited. The relevance of high-dose rodent carcinogenicity findings to human use remains a subject of debate.
Human trials of GW501516 were small and short in duration. They examined lipid levels, glucose handling, and other metabolic markers, but the programs were halted after the animal cancer findings. No approved therapeutic product exists, and published human data are insufficient for establishing long-term safety. Reports of use for athletic performance come mainly from non-clinical settings and cannot be verified through controlled trials. Independent testing of products sold as cardarine has found inconsistent purity and labeling.
Activation of PPARδ changes transcription of genes involved in fatty acid transport, mitochondrial function, and skeletal muscle fuel preference. In rodent studies, pharmacological PPARδ activation was associated with increased endurance and altered body composition. These findings generated interest in performance enhancement, but species differences and study designs limit direct extrapolation to humans. Small human trials were conducted in the 2000s and later discontinued. The extent to which cardarine produces similar metabolic or performance effects in people remains an open question.
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
==== Diabetes ==== The high doses of nicotinic acid used to treat hyperlipidemia have been shown to elevate fasting blood glucose in people with type 2 diabetes. Long-term nicotinic acid therapy was also associated with an increase in the risk of new-onset type 2 diabetes.
=== 1930s–1940s === The propagandist tradition consists of films made with the explicit purpose of persuading an audience of a point. One of the most celebrated and controversial propaganda films is Leni Riefenstahl's film Triumph of the Will (1935), which chronicled the 1934 Nazi Party Congress and was commissioned by Adolf Hitler. Leftist filmmakers Joris Ivens and Henri Storck directed Borinage (1931) about the Belgian coal mining region. Luis Buñuel directed a "surrealist" documentary Las Hurdes (1933). Pare Lorentz's The Plow That Broke the Plains (1936) and The River (1938) and Willard Van Dyke's The City (1939) are notable New Deal productions, each presenting complex combinations of social and ecological awareness, government propaganda, and leftist viewpoints. Frank Capra's Why We Fight (1942–1944) series was a newsreel series in the United States, commissioned by the government to convince the U.S. public that it was time to go to war. Constance Bennett and her husband Henri de la Falaise produced two feature-length documentaries, Legong: Dance of the Virgins (1935) filmed in Bali, and Kilou the Killer Tiger (1936) filmed in Indochina. In Canada, the Film Board, set up by John Grierson, was set up for the same propaganda reasons. It also created newsreels that were seen by their national governments as legitimate counter-propaganda to the psychological warfare of Nazi Germany orchestrated by Joseph Goebbels.
It also ran Camp Hardy Combat Training Center in the Northern Training Area of Okinawa to train SF, Navy SEALs, and US Marines deploying to Vietnam. It also earned the Meritorious Unit Commendation for its work during the year 1973. Following the war in South Vietnam, and the withdrawal of American military forces from Southeast Asia, the emphasis on military actions shifted away from the Asia-Pacific region and focused more on Europe and NATO. Special Forces, which had grown to a total of seven groups in 1963, faced severe cuts in the peacetime army; as a result, 1st Group was inactivated 28 June 1974 at Ft. Bragg, NC. After a 10-year hiatus, the need for an Asian unconventional warfare force was recognized, and Alpha Company, 1st Battalion was reactivated at Fort Bragg on 15 March 1984. This company and the remainder of the 1st Battalion were assembled and deployed to Torii Station, Okinawa during the spring and summer of 1984. The 2nd and 3rd Battalions, along with Headquarters and Service Company were officially reactivated 4 September 1984 at Fort Lewis, Washington. Brought back to life as part of overall growth in the support to U.S. strategic efforts in Asia, the unit focused on the Pacific Command area of operations but were routinely deployed out of Asia to support unified commanders throughout the world. Unit members supported theater security engagement within the PACOM area of operations, contingency operations in Haiti, Central Asia, and Bosnia.
=== October === October 1 The US imposes new sanctions on Iran, targeting rail, automotive, manufacturing, and steel sectors, as well as overseas suppliers, saying that the goal is to economically isolate the Iranian government. The US military starts sending about 9,000 soldiers to the Middle East on naval ships, such as the USS Makin Island amphibious readiness group and the USS Theodore Roosevelt carrier strike group. October 2 The US imposes sanctions on Hamas' financing network, which includes two French-based funds. Alabama state representative Brett Easterbrook is arrested on charges of first-degree human trafficking and prostitution as part of a sting. At least a dozen other men are arrested. October 3 – Trump establishes a task force to examine the risks and opportunities of AI and recommend what role the federal government should play in overseeing the technology without compromising competitiveness with China. October 4 The State Department announces that the US "kicked out" two members of the Iranian delegation who attended the recent United Nations General Assembly after they ignored an order to leave the country long after the General Assembly had ended. Trump withdraws all US bombers from RAF Fairford, a British air base targeted by an attack that the UK linked to the Iranian government, due to urgent concerns about a potentially complex drone attack ordered by the IRGC as part of a plot to target the aircraft and kill American soldiers at RAF Fairford, which is loosely modeled after Ukraine's Operation Spiderweb.
Sources: en.wikipedia.org
===== Sulfonylureas ===== Sulfonylureas act by increasing insulin release from the beta cells in the pancreas. A 2019 systematic review suggested that there is limited evidence if the combined use of metformin with sulfonylurea compared to the combination of metformin plus another glucose-lowering intervention, provides benefit or harm in mortality, severe adverse events, macrovascular and microvascular complications. Combined metformin and sulfonylurea therapy did appear to lead to a higher risk of hypoglycemia. Metformin is available combined with the sulfonylureas glipizide (Metaglip) and glibenclamide (US: glyburide) (Glucovance). Generic formulations of metformin/glipizide and metformin/glibenclamide are available (the latter is more popular).
=== Metabolism === Nicotine decreases hunger and as a consequence food consumption, alongside increasing energy expenditure. The majority of research shows that nicotine reduces body weight, but some researchers have found that nicotine may result in weight gain under specific types of eating habits in animal models. Nicotine effect on weight appears to result from nicotine's stimulation of α3β4 nAChR receptors located in the POMC neurons in the arcuate nucleus and subsequently the melanocortin system, especially the melanocortin-4 receptors on second-order neurons in the paraventricular nucleus of the hypothalamus, thus modulating feeding inhibition. POMC neurons are a precursor of the melanocortin system, a critical regulator of body weight and peripheral tissue such as skin and hair.
The Joint Committee for Traceability in Laboratory Medicine or JCTLM is collaboration between the International Bureau of Weights and Measures (BIPM), the International Federation for Clinical Chemistry and Laboratory Medicine (IFCC), and the International Laboratory Accreditation Cooperation (ILAC). The goal of the JCTLM is to provide a worldwide platform to promote and give guidance on internationally recognized and accepted equivalence of measurements in laboratory medicine and traceability to appropriate measurement standards.
Sources: en.wikipedia.org
=== Grhl2 === Grhl2 is involved in lower jaw formation of mammals, among other craniofacial developmental processes. It is also evolutionarily closest to Grhl1, compared to Grhl3, while still exhibiting the highly conserved functions that all Grhl genes share. It also appears that Grhl2 is involved in the fusion of the facial bones and that disruption to the regulation of Grhl2 can lead to cranioschisis/split face during embryonic development, often causing death. Continuing with the trend of incomplete fusion, the formation of the neural tube and abdominal wall is also regulated by Grhl2, evident by observation of incomplete closure of these structures, leading to spina bifida and thoracoabdominoschisis, following loss of Grhl2 function in mutant mice models for Grhl2. Additionally, over-expression of Grhl2 can also lead to mice developing spina bifida, showing the delicate balance in regulation required for Grhl2. Grhl2 is also related to breast cancer progression due to its ability to regulate epithelial cells and other processes such as epithelial-mesenchymal transition (EMT), although it is not known if EMT is promoted or inhibited by Grhl2. However, tumour progression is more associated with the epithelial tissue phenotype. Interestingly, within zebrafish there are two separate orthologues, grhl2a and grhl2b. Comparing the homology of these two orthologues to the human and mice equivalent, Grhl2, showed that grhl2b had 36 out of 47 amino acids identical (77% identical), meaning it was slightly more conserved than grhl2a, which had 34 out of 47 (72% identical).
Another advantage is the accuracy of the method. In an analysis performed by Li et al., it was found that use of fluorescence detection techniques yielded 100% detection accuracy in 13 of 15 collected images. The remaining two had relative errors around 6%. Another advantage of fluorescence detection is that it allows for quantitative analysis of droplet spacing in a sample. This is done by use of temporal measurements and the flow velocity of the analyte. The time spacing between signals allows for calculation of droplet spacing. Further fluorescence analysis of microfluidic droplet samples can be used to measure the fluorescent lifetime of samples, providing additional information that is not obtainable for fluorescence intensity measurements alone. The applications of fluorescence detection are varied, with many of its uses centered in biological applications. Frenz et al. utilized fluorescence detection of droplets to examine enzyme kinetics. For this experiment, b-lactamase interacted with fluorocillin, a fluorogenic substrate. Fluorescence of the droplets was measured at multiple time intervals to examine the change with time. This detection method goes beyond biological applications, though, and allows for the physical study of droplet formation and evolution. For example, Sakai et al. used fluorescence detection to monitor droplet size. This was done by collecting fluorescence data to calculate the concentration of a fluorescent dye within a single droplet, thus allowing size growth to be monitored.
is the water content of blood, approximately 0.825 w/v for men and 0.838 w/v for women. These calculations assume Widmark's zero-order model for the effects of metabolization, and assume that TBW is almost exactly the volume of distribution of ethanol. Using a more complex model that accounts for non-linear metabolism, Norberg found that Vd was only 84-87% of TBW. This finding was not reproduced in a newer study which found volumes of distribution similar to those in the literature.
Sources: en.wikipedia.org
It binds and activates PPARδ, a nuclear receptor that influences gene expression related to fatty acid metabolism and energy balance. This mechanism has been studied mainly in animals and cell models, not established as a safe human therapy.
No. It is not an anabolic-androgenic steroid; it is a synthetic PPARδ agonist. Because it is banned in sport, it is sometimes grouped with doping agents even though its chemical class differs from steroids.
Human data are limited and development was discontinued, so major effects and long-term risks are not well characterized. Some early studies examined metabolic markers, but they do not provide a basis for unsupervised use.
No. Cardarine is GW501516, a PPARδ agonist, while SARMs act on androgen receptors. The two classes are often grouped in informal discussions despite different mechanisms.