GW501516 raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-03-23 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Primary target | PPARδ (NR1C2) | Nuclear receptor involved in lipid metabolism |
| Preclinical effect | Increased fatty acid oxidation | Observed in rodent studies |
| Key safety signal | Tumors in rodents after long-term exposure | Contributed to halted clinical development |
| Human trial status | No approved product; development stopped | Limited short-term metabolic data |
| Sport regulatory status | Prohibited at all times | WADA hormone and metabolic modulators class |
Cardarine is the common name for GW501516, a synthetic compound studied as a peroxisome proliferator-activated receptor delta agonist. Researchers developed it to explore treatments for lipid disorders and metabolic conditions. It is not an approved medicine in any country. Early clinical work examined changes in HDL cholesterol and triglycerides, but development was discontinued after animal studies raised concerns about cancer. The compound remains available as a research chemical and appears in discussions of performance enhancement.
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.
Preclinical research reported that GW501516 increased running endurance in mice and improved lipid profiles in some animal species. Early human trials explored effects on high-density lipoprotein cholesterol, triglycerides, and glucose handling, but the program was discontinued. Published human data are sparse and do not establish efficacy for any condition. Studies also examined PPAR delta in cancer biology, with conflicting findings across models. The relationship between receptor activation, tissue context, and disease risk remains an active area of investigation.
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.
=== Grain-free and low-carbohydrate === Some dog food products differentiate themselves as grain- or carbohydrate-free to offer the consumer an alternative, claiming carbohydrates in pet foods to be fillers with little or no nutritional value. A study published in Nature suggests that domestic dogs' ability to easily metabolize carbohydrates may be a key difference between wolves and dogs. Some consumers and manufacturers say dogs perform better on grain-free diets, while some veterinarians doubt this for a lack of scientific evidence. In 2019, a study comparing dry dog food that was manufactured in the United States found that 75% of food containing feed grade grains also contained measurable levels of various mycotoxins (discussed below), while none of the grain-free dry diets tested had any detectable levels of mycotoxins. Feed grade (lower quality grade) grains that are allowed to spoil and become moldy are the suspected source of the mycotoxins. This is the first published study to show a potential health benefit to feeding grain-free commercial dry pet foods. In 2019, the U.S. Food and Drug Administration identified 16 dog food brands linked to canine heart disease. The FDA has investigated more than 500 cases of dilated cardiomyopathy (DCM) in dogs eating food marketed as grain-free. The 16 brands are: Acana, Zignature, Taste of the Wild, 4Health, Earthborn Holistic, Blue Buffalo, Nature's Domain, Fromm, Merrick, California Natural, Natural Balance, Orijen, Nature's Variety, NutriSource, Nutro, and Rachael Ray Nutrish.
Registered voters: 425,305, valid: 371,189, turnout: 87.3% To honour the exceptionally high percentage of pro-German votes in the district of Oletzko, with 2 votes for Poland compared to 28,625 for Germany, the district town Marggrabowa (i.e. Margrave town) was renamed "Treuburg" (TreueGerman = "loyalty") in 1928, with the district following this example in 1933. In the villages of Lubstynek (Klein Lobenstein), Czerlin (Klein Nappern) and Groszki (Groschken) in the District of Osterode in East Prussia (Ostróda), situated directly at the border, the majority voted for Poland and joined Poland after the plebiscite. Other Polish-majority villages were scarce but would have been more numerous if they had not been surrounded by Mazurian German disposed villages, which made a geographical connection with Poland improbable and so votes for Poland would not be useful. The strategic importance of the Prussian Eastern Railway line Danzig-Warsaw passing through the area of Soldau in the Neidenburg District caused it to be transferred to Poland without a plebiscite; it was renamed Działdowo.[1]
replication 1. The process by which certain biological molecules, notably the nucleic acids DNA and RNA, produce copies of themselves. 2. A technique used to estimate technical and biological variation in experiments for statistical analysis of microarray data. Replicates may be technical replicates, such as dye swaps or repeated array hybridizations, or biological replicates, biological samples from separate experiments which are used to test the effects of the same experimental treatment.
=== Physical features === LS is recognized as being part of a spectrum of conditions that affect the Hypothalamic–pituitary–somatotropic axis and cause significant derangements in human growth, development, and metabolism. Along this spectrum of conditions, individuals with LS and growth hormone deficiency display short stature, while individuals with acromegaly and gigantism result in the opposite phenotype of tall stature. In addition to short stature, other characteristic physical symptoms of LS include: prominent forehead, depressed nasal bridge, underdevelopment of mandible, truncal obesity, and micropenis in males. Left untreated, the average height attained by individuals with LS are approximately 4–4.5 feet (1.2–1.4 m) in women/men respectively. Additional physical features include delayed bone age, hypogonadism, blue sclera, high-pitched voice, acrohypoplasia, sparse hair growth, and crowded teeth. The breasts of females reach normal size, and in some are large in relation to body size. It has been suggested that hyperprolactinemia may contribute to the enlarged breast size. Seizures are frequently seen secondary to hypoglycemia. Some genetic variations decrease intellectual capacity. Laron syndrome patients also do not develop acne, except temporarily during treatment with IGF-1 (if performed).
Sources: en.wikipedia.org
Since then, treatment had continued in the cities that participated in the pilot study, until heroin maintenance was permanently included into the national health system in May 2009. As of 2021, the country offers heroin-assisted treatment by prescribing medical-grade heroin is typically prescribed in combination with methadone and psychosocial counseling. A heroin maintenance programme has existed in the United Kingdom (UK) since the 1920s, as drug addiction was seen as an individual health problem. Addiction to opiates was rare in the 1920s and was mostly limited to either middle-class people who had easy access due to their profession, or people who had become addicted as a side effect of medical treatment. In the 1950s and 1960s a small number of doctors contributed to an alarming increase in the number of people who are experiencing addiction in the U.K. through excessive prescribing—the U.K. switched to more restrictive drug legislation as a result. However, the British government is again moving towards a consideration of heroin prescription as a legitimate component of the National Health Service (NHS). Evidence has shown that methadone maintenance is not appropriate for all people who are dependent on opioids and that heroin is a viable maintenance drug that has shown equal or better rates of success. A committee appointed by the Norwegian government completed an evaluation of research reports on heroin maintenance treatment that were available internationally.
1,3-Dibromopropane is an organobromine compound with the formula (CH2)3Br2. It is a colorless liquid with sweet odor. It is used in organic synthesis to form C3-bridged compounds such as through C-N coupling reactions. 1,3-Dibromopropane was used in the first cyclopropane synthesis in 1881, known as the Freund reaction.
In mass spectrometry, an ion funnel is a device used to focus a beam of ions using a series of stacked ring electrodes with decreasing inner diameter. A combined radio frequency and fixed electrical potential is applied to the grids. In electrospray ionization-mass spectrometry (ESI-MS), ions are created at atmospheric pressure, but are analyzed at subsequently lower pressures. Ions can be lost while they are shuttled from areas of higher to lower pressure due to the transmission process caused by a phenomenon called Joule expansion or “free-jet expansion.” These ion clouds expand outward, which limits the amount of ions that reach the detector, so fewer ions are analyzed. The ion funnel refocuses and transmits ions efficiently from those areas of high to low pressure.
Sources: en.wikipedia.org
Glaxo Wellcome had licensed the drug from Sankyo Company of Japan and had sold it in Britain from October 1, 1997. On May 17, 1998, a 55-year-old patient named Audrey LaRue Jones died of acute liver failure after taking troglitazone. Importantly, she had been monitored closely by physicians at the National Institutes of Health (NIH) as a participant in the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) diabetes prevention study. This called into question the efficacy of the monitoring strategy. The NIH responded on June 4 by dropping troglitazone from the study. Dr. David J. Graham, an FDA epidemiologist charged with evaluating the drug, warned on March 26, 1999, of the dangers of using it and concluded that patient monitoring was not effective in protecting against liver failure. He estimated that the drug could be linked to over 430 liver failures and that patients incurred 1,200 times greater risk of liver failure when taking Rezulin. Dr. Janet B. McGill, an endocrinologist who had assisted in the Warner–Lambert's early clinical testing of Rezulin, wrote in a March 1, 2000, letter to Sen. Edward M. Kennedy (D-Mass.): "I believe that the company... deliberately omitted reports of liver toxicity and misrepresented serious adverse events experienced by patients in their clinical studies." On March 21, 2000, the FDA withdrew the drug from the market. Dr. Robert I. Misbin, an FDA medical officer, wrote in a March 3, 2000, letter to Senator John Ashcroft of strong evidence that Rezulin could not be used safely.
On 13 August 2008, George Friedman, US military analyst, and a CEO of a US-based think-tank Stratfor, wrote in the institution's report: "There had been a great deal of shelling by the South Ossetians of Georgian villages for the previous three nights, but while possibly more intense than usual, artillery exchanges were routine. [...] It is very difficult to imagine that the Georgians launched their attack against U.S. wishes. The Georgians rely on the United States, and they were in no position to defy it. [...] the United States either was unaware of the existence of Russian forces, or knew of the Russian forces but -- along with the Georgians -- miscalculated Russia's intentions. [...] Putin did not want to re-establish the Soviet Union, but he did want to re-establish the Russian sphere of influence in the former Soviet Union region. [...] He did not want to confront NATO directly, but he did want to confront and defeat a power that was closely aligned with the United States, had U.S. support, aid and advisers and was widely seen as being under American protection. Georgia was the perfect choice. [...] The war in Georgia, therefore, is Russia's public return to great power status.
Mathematical Biology is a two-part monograph on mathematical biology first published in 1989 by the applied mathematician James D. Murray. It is considered to be a classic in the field and sweeping in scope.
Organoleptic examination or sensory analysis is the most basic form of investigation for textiles. This can include visible damage as well as smells that indicate pollutants, humidity, and decomposition of organic materials. Sampling should be used minimally to help with the inspection of fibers. Sampling requires the extraction of a small amount of the material. Inspection of fibers can include Fourier transform infrared (FTIR), Raman, and attenuated total reflectance (ATR) spectroscopy, “When sampling a work of art is deemed appropriate, scientists routinely use scanning electron microscopy–energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR).” (ATR): attenuated total reflectance is a sampling technique used in conjunction with infrared spectroscopy which enables samples to be examined directly in the solid or liquid state without further preparation. This process is ideal for optically dense materials. (FTIR): Fourier transform infrared spectroscopy is a technique used to obtain an infrared spectrum of absorption or emission of a solid, liquid or gas. An FTIR spectrometer simultaneously collects high-resolution spectral data over a wide spectral range. This process requires computer processing to convert raw data into usable results related to wavelengths that indicate how materials absorb or emit infrared light.
Sources: en.wikipedia.org
Rodent studies reported increased endurance and fat oxidation after GW501516 exposure. Long-term studies also found higher rates of some tumors, which led to halted development.
Small short-term human trials examined metabolic markers such as lipids and glucose. The trials did not continue after rodent cancer findings, so long-term human safety is unknown.
Controlled human trials have not established a performance benefit. Anecdotal reports exist, but they are not reliable evidence.
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.