If you have been reading about anti-doping 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.
Last reviewed on 2025-11-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| 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 |
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.
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.
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.
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.
In 1871, Dmitri Mendeleev predicted the existence of an element between thorium and uranium. The actinide series was unknown at the time, so Mendeleev positioned uranium below tungsten in group VI, and thorium below zirconium in group IV, leaving the space below tantalum in group V empty. Until the general acceptance of the actinide concept in the late 1940s, periodic tables were published with this structure. For a long time, chemists searched for eka-tantalum as an element with similar chemical properties to tantalum, making a discovery of protactinium nearly impossible. Tantalum's heavier analogue was later found to be the transuranic element dubnium – although dubnium is more chemically similar to protactinium, not tantalum. In 1900, William Crookes isolated protactinium as an intensely radioactive material from uranium; however, he could not characterize it as a new chemical element and thus named it uranium X (UX). Crookes dissolved uranium nitrate in ether, and the residual aqueous phase contained most of the 23490Th and 23491Pa. His method was used into the 1950s to isolate 23490Th and 23491Pa from uranium compounds. Protactinium was first identified in 1913, when Kasimir Fajans and Oswald Helmuth Göhring encountered the isotope 234mPa during their studies of the decay chains of uranium-238: 23892U → 23490Th → 234m91Pa → 23492U. They named the new element "brevium" (from the Latin word brevis, meaning brief or short) because of the short half-life of 1.16 minutes for 234m91Pa (uranium X2).
Thomas also spent part of his summer holidays with Jim's sister, Rachel Jones, at neighbouring Pentrewyman farm, where he spent his time riding Prince the cart horse, chasing pheasants and fishing for trout. All these relatives were bilingual, and many worshipped at Smyrna chapel in Llangain where the services were always in Welsh, including Sunday School which Thomas sometimes attended. There is also an account of the young Thomas being taught how to swear in Welsh. His schoolboy friends recalled that "It was all Welsh—and the children played in Welsh...he couldn't speak English when he stopped at Fernhill...in all his surroundings, everybody else spoke Welsh..." At the 1921 census, 95% of residents in the two parishes around Fernhill were Welsh speakers. Across the whole peninsula, 13%—more than 200 people—spoke only Welsh. A few fields south of Fernhill lay Blaencwm, a pair of stone cottages to which his mother's Swansea siblings had retired, and with whom the young Thomas and his sister, Nancy, would sometimes stay. A couple of miles down the road from Blaencwm is the village of Llansteffan, where Thomas used to holiday at Rose Cottage with another Welsh-speaking aunt, Anne Williams, his mother's half-sister who had married into local gentry. Anne's daughter, Doris, married a dentist, Randy Fulleylove. The young Dylan also holidayed with them in Abergavenny, where Fulleylove had his practice. Thomas's paternal grandparents, Anne and Evan Thomas, lived at The Poplars in Johnstown, just outside Carmarthen. Anne was the daughter of William Lewis, a gardener in the town.
The Mareth Line constituted one of two fronts in the Tunisia Campaign, the second being to the north-west, where the British First Army and American II Corps, firmly established in formerly Vichy-held Morocco and Algeria following Operation Torch in November 1942, were gradually pushing the Axis forces under Hans-Jürgen von Arnim back towards Tunis. After von Arnim won a decisive victory over the Americans at the Battle of Sidi Bou Zid in mid-February 1943, destroying over 100 US tanks, the Eighteenth Army Group was formed under the British General Harold Alexander to co-ordinate the actions of the Allied forces on both Tunisian fronts. The Eighth Army under Montgomery spent February at Medinine in south-eastern Tunisia. Expecting an imminent attack by the Axis, the Eighth Army mustered every anti-tank gun it could from Egypt and Libya. The 102nd (Northumberland Hussars) Anti-Tank Regiment, including the Rhodesian Anti-Tank Battery under Major Savory, duly advanced west from Benghazi and reached the front on 5 March 1943. The Germans and Italians assaulted Medinine the next day, but failed to make much progress and abandoned their attack by the evening. The Rhodesian gunners, held in reserve, did not take part in the engagement but were attacked from the air. The Rhodesians of the KRRC, now under the 7th Motor Brigade, moved up from Libya during early March. No. 237 (Rhodesia) Squadron, which had spent 1942 and the first months of 1943 in Iran and Iraq, returned to North Africa the same month, with the future Prime Minister Ian Smith in its ranks as a Hurricane pilot.
Sources: en.wikipedia.org
=== Autoimmune diseases === Problems posed by the differences in the human and rodent immune systems have been overcome using a few strategies, so as to enable researchers to study autoimmune disorders using humanized models. As a result, the use of humanized mouse models has extended to various areas of immunology and disease research. For instance, humanized mice have been utilized to study human-tropic pathogens, liver cancer models, and the comparison of mouse models to human diseases NSG mice engrafted with PBMCs and administered with myelin antigens in Freund's adjuvant, and antigen-pulsed autologous dendritic cells have been used to study multiple sclerosis. Similarly, NSG mice engrafted with hematopoietic stem cells and administered with pristane have been used for studying lupus erythematosus. Furthermore, NOG mice engrafted with PBMCs has been used to study mechanisms of allografts rejection in vivo. The development of humanized mouse models has significantly advanced the study of autoimmune disorders and various areas of immunology and disease research. These models have provided a platform for investigating human diseases, immune responses, and therapeutic interventions, bridging the gap between human and rodent immune systems and offering valuable insights into disease pathogenesis and potential therapeutic strategies.
Chebulagic acid is a benzopyran tannin and an antioxidant that has many potential uses in medicine. It has been found to be immunosuppressive, hepatoprotective, and a potent alpha-glucosidase inhibitor, a human gut enzyme useful in diabetic studies. It has been shown to be active against Staphylococcus aureus and Candida albicans. It is found in the plants Terminalia chebula, T. citrina and T. catappa. It is formed from geraniin through a glutathione-mediated conversion.
== Synthesis == Like all bacterial extracellular proteases thermolysin is first synthesised by the bacterium as a pre-proenzyme. Thermolysin is synthesized as a pre-proenzyme consisting of a signal peptide 28 amino acids long, a pro-peptide 204 amino acids long and the mature enzyme itself 316 amino acids in length. The signal peptide acts as a signal for translocation of pre-prothermolysin to the bacterial cytoplasmic membrane. In the periplasm pre-prothermolysin is then processed into prothermolysin by a signal peptidase. The prosequence then acts as a molecular chaperone and leads to autocleavage of the peptide bond linking pro and mature sequences. The mature protein is then secreted into the extracellular medium.
This barrier was extremely important in shaping the expansion of the United States in the colonial era. Much of the range's economy was historically based on logging and coal mining, which attracted many migrants who contributed to the genesis of a new cultural region. Though the decline of these industries was an economic detriment, many communities have pivoted to manufacturing and services. Tourism has also become increasingly prevalent: the mountains are home to the very popular Appalachian Trail, a 2,175-mile (3,500 km) hiking trail that runs from Mount Katahdin in Maine to Springer Mountain in Georgia. The International Appalachian Trail is an extension of this hiking trail into the Canadian portion of the Appalachian range in New Brunswick and Quebec.
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.