PPARδ agonist raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-12-12. Anything still debated is marked as such rather than presented as settled.
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.
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.
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 |
|---|---|---|
| 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 |
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.
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.
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.
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.
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.
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.
Cigarettes are a frequent source of deadly fires in private homes, which prompted both the European Union and the United States to require cigarettes to be fire-standard compliant. According to Simon Chapman, a professor of public health at the University of Sydney, reduction of burning agents in cigarettes would be a simple and effective means of dramatically reducing the ignition propensity of cigarettes. Since the 1980s, prominent cigarette manufacturers such as Philip Morris and R.J. Reynolds have developed fire safe cigarettes, but Phillip Morris was later the subject of a government lawsuit for allegedly hiding the even greater dangers associated with their brand of such cigarettes. The burn rate of cigarette paper is regulated through the application of different forms of microcrystalline cellulose to the paper. Cigarette paper has been specially engineered by creating bands of different porosity to create "fire-safe" cigarettes. These cigarettes have a reduced idle burning speed which allows them to self-extinguish. This fire-safe paper is manufactured by mechanically altering the setting of the paper slurry. New York was the first U.S. state to mandate that all cigarettes manufactured or sold within the state comply with a fire-safe standard. Canada has passed a similar nationwide mandate based on the same standard. All U.S. states are gradually passing fire-safe mandates. The European Union in 2011 banned cigarettes that do not meet a fire-safety standard.
== Biology and medicine == Gamma-glutamyltransferase, an enzyme that catalyzes the reaction between a peptide and an amino acid Glutathione hydrolase, an enzyme that hydrolyzes glutathione A codon for the amino acid Glycine Germline gene therapy, to treat genetic diseases
=== β-α-β motif === Due to the chirality of their component amino acids, all strands exhibit right-handed twist evident in most higher-order β-sheet structures. In particular, the linking loop between two parallel strands almost always has a right-handed crossover chirality, which is strongly favored by the inherent twist of the sheet. This linking loop frequently contains a helical region, in which case it is called a β-α-β motif. A closely related motif called a β-α-β-α motif forms the basic component of the most commonly observed protein tertiary structure, the TIM barrel.
Sources: en.wikipedia.org
1947 - the Ciba Award from the Endocrine Society 1951 - the Award of American Chemical Society 1955 - the Amory Prize of American Academy of Arts and Sciences 1962 - the first Albert Lasker Award for Basic Medical Research 1970 - the Scientific Achievement Award from American Medical Association 1971 - the National Award of the American Cancer Society 1972 - the Nicholas Andry Award from the Association of Bone and Joint Surgeons 1977 - the Lewis Price of the American Philosophical Society 1979 - the William H. Nichols Medal of the American Chemical Society 1981 - the Koch Award of the Endocrine Society 1987 - the Alan E. Pierce Award (now R. Bruce Merrifield Award) from American Peptide Society Li was elected to the following academies:
== Protein == Seryl-tRNA synthetase is made up of 514 amino acid residues as weighs 58,777 Da. It exists as a homodimer of two identical subunits, with the tRNA molecule binding across the dimer by similarity. It has two distinct domains:
==== Identification ==== Calliphora vomitoria is often not the only species present at carrion, so some process of identification of the correct species is needed in order to avoid false estimates of the time of death due to their having different developmental cycles. In the past, simple morphological differences are used to differentiate between species. However, it is very difficult in crime scenes because more often than not these sites are not ideal, with preservation of insect species far from good. Methods that can best differentiate between the species are DNA, mitochondrial DNA, and the COI gene. The COI gene used in conjunction with restriction enzymes has been shown to be a relatively fast and simple method of distinguishing between blowfly species with good accuracy.
== Modern-day Cossack identity == Ethnic, or "born" (prirodnye), Cossacks are those who can trace, or claim to trace, their ancestry to people and families identified as Cossack in the Tsarist era. They tend to be Christian, practicing as Orthodox Christians or Old Believers; though there are growing numbers of Rodnovers, especially among Ukrainian Cossacks. Others may be initiated as Cossacks, particularly men in military service. Such initiates may be neither ethnic Slavs, nor Christian. Not all agree that such initiates should be considered Cossack. There is no consensus on an initiation rite or rules. In other cases, individuals may wear Cossack uniform and pass themselves off as Cossack, perhaps because there is a large ethnic Cossack population in the area and the person wants to fit in. Others adopt Cossack clothing in an attempt to take on some of their mythic status. Ethnic Cossacks refer to the re-enactors as ryazhenye (ряженые, or "dressed up phonies"). Because of the lack of consensus on how to define Cossacks, accurate numbers are not available. According to the Russian Census of 2010, 67,573 people identify as ethnic Cossack in Russia. Between 3.5 and 5 million people associate themselves with the Cossack identity in Europe and across the world.
Sources: en.wikipedia.org
== Market == As of 2012, the pharmaceutical industry had expressed strong interest in developing botanical drugs, with more than 500 applications pending at the FDA. Part of the interest stems from a desire to address the Chinese market, where herbal medicines remain widely used and had $13 billion in sales in 2011.
=== Contract research organizations === Contract research organizations (CROs) provide services to the life science industries along product development. There are more than 2000 CROs operating worldwide, representing revenues of more than $20 billion. There is a key difference between "Product" and "Patient" CROs. Whereas the production sites of CMOs are multipurpose plants, allowing for the production of tens to hundreds of tons of fine chemicals, the work places of patient CROs are the test persons for the clinical trials, and the work places of product CROs are the laboratory benches. Major customers for CRO services are the large global pharmaceutical companies. Half a dozen companies (Pfizer, GlaxoSmithKline, Sanofi-Aventis, AstraZeneca, Johnson & Johnson, and Merck & Co.) alone absorb about one third of all CRO spending. Similarly to CMOs, biotech start-up CROS, with their dichotomy between ambitious drug development programs and limited resources, are the second most promising prospects. Product CROs primarily provide sample preparation, process research and development services. Pilot plants, which produce 100 kg quantities, are combinations of development CROs and CMOs, and ae part of the arsenal of both types of enterprise. Tere are more 100 Product CROs. Most of them are privately held and have revenues of $10–$20 million per year or less, adding up to a total business in the range of $1.5-$2 billion. Examples include:
The company also sponsored a complaint to the FDA, expressing concern that buprenorphine/naloxone sublingual tablets (the very product they formerly produced) were unsafe, requesting that applications for regulatory approval of generic products by other pharmaceutical companies (their competitors) be rejected by the US Food and Drug Administration.
== Biosynthesis == Phosphoenolpyruvate and erythrose-4-phosphate condense to form 3-deoxy-D-arabinoheptulosonate-7-phosphate (DAHP), in a reaction catalyzed by the enzyme DAHP synthase. DAHP is then transformed to 3-dehydroquinate (DHQ), in a reaction catalyzed by DHQ synthase. Although this reaction requires nicotinamide adenine dinucleotide (NAD) as a cofactor, the enzymic mechanism regenerates it, resulting in the net use of no NAD.DHQ is dehydrated to 3-dehydroshikimic acid by the enzyme 3-dehydroquinate dehydratase, which is reduced to shikimic acid by the enzyme shikimate dehydrogenase, which uses nicotinamide adenine dinucleotide phosphate (NADPH) as a cofactor.
Furthermore, water conservation is also accomplished as insects are cold-blooded and are able to meet water requirements through their feed. Thus, insects may be an acceptable source of protein for pets. To learn more about sustainability of insect rearing, see Insect farming.
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. 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.