Everything below concerns LC-MS/MS. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-04-14. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Legal status varies by country. In some places, cardarine is controlled under medicines or psychoactive substances laws; in others, it may be sold with minimal oversight as a research chemical. Customs agencies have intercepted shipments, and several national health agencies have issued warnings about products marketed for bodybuilding or performance enhancement. The lack of a standardized pharmaceutical supply means identity, purity, and contamination levels can differ widely between samples. These factors make cardarine a regulatory and public health concern rather than a conventional prescription drug.
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.
| Property | Value | Notes |
|---|---|---|
| IUPAC name | {4-[({4-methyl-2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-5-yl}methyl)sulfanyl]phenoxy}acetic acid | Systematic name for GW501516 |
| CAS Registry Number | 317318-70-0 | Unique identifier for the parent compound |
| Molecular formula | C21H18F3NO3S2 | Includes carbon, hydrogen, fluorine, nitrogen, oxygen, and sulfur |
| Molecular weight | 453.5 g/mol | Approximate value for the neutral form |
| Appearance | White to off-white powder | Typical description for purified laboratory material |
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.
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.
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.
== Signs and symptoms == Often, every joint in a patient with arthrogryposis is affected; in 84% all limbs are involved, in 11% only the legs, and in 4% only the arms are involved. Every joint in the body, when affected, displays typical signs and symptoms: for example, the shoulder (internal rotation); wrist (volar and ulnar); hand (fingers in fixed flexion and thumb in palm); hip (flexed, abducted and externally rotated, frequently dislocated); elbow (extension and pronation) and foot clubfoot and less commonly congenital vertical talus. Range of motion can be different between joints because of the different deviations. Some types of arthrogryposis like amyoplasia have a symmetrical joint/limb involvement, with normal sensations. The contractures in the joints can result in delayed walking development in the first five years, but severity of contractures do not necessarily predict eventual walking ability or inability. Intelligence is normal to above normal in children with amyoplasia, but it is not known how many of these children have an above-normal intelligence, and there is no literature available about the cause of this syndrome. There are a few syndromes like the Freeman–Sheldon and Gordon syndrome, which have craniofacial involvement. The amyoplasia form of arthrogryposis is sometimes accompanied with a midline facial hemangioma. Arthrogryposis is not a diagnosis but a clinical finding, so this disease is often accompanied with other syndromes or diseases. These other diagnoses could affect any organ in a patient.
== History == It is commonly stated that the modern e-cigarette was patented in 2003 by Chinese pharmacist Hon Lik, but tobacco companies had been developing nicotine aerosol generation devices since as early as 1963.
3 November Nixon addressed the nation on television and radio at 9:30 p.m., Washington time, to announce his plans to end American involvement in the war. Nixon gave his reasons for rejecting immediately removing all troops, framing that option as the "first defeat in our Nation's history" that "would result in a collapse of confidence in American leadership, not only in Asia but throughout the world." Nixon instead reiterated his plan for Vietnamization, "the complete withdrawal of all U.S. combat ground forces and their replacement by South Vietnamese forces on an orderly scheduled timetable" but added that he did not intend to announce details of the timetable. In closing, he described the people who would support his plan for a drawdown as "the great silent majority of my fellow Americans", in contrast to a "vocal minority" of protesters which, if their will prevailed "over reason and the will of the majority", would mean that the United States would have "no future as a free society." A Gallup poll the next day showed that 77% of Americans supported Nixon's Vietnam policy.
Sources: en.wikipedia.org
== Medical uses == Cipaglucosidase alfa is a long-term enzyme replacement therapy used in combination with the enzyme stabilizer miglustat for the treatment of adults with late-onset Pompe disease (acid α-glucosidase [GAA] deficiency).
Clinicians may improperly connect transgender people's symptoms to their gender transition, a phenomenon known as trans broken arm syndrome. Trans broken arm syndrome is particularly prevalent among mental health practitioners, but exists in all fields of medicine. Misguided investigation of transition-related causes can frustrate patients and cause delay in or refusal of treatment, or misdiagnosis and prescription of a wrong treatment. Misattribution of symptoms to gender-affirming hormone therapy may also cause doctors to erroneously recommend the patient stop taking hormones. Trans broken arm syndrome may also manifest as health insurance companies refusing to pay for treatments, claiming that a mental or physical health problem is inevitable or untreatable due to the patient's transgender status or that a treatment would be too experimental because the patient is transgender. According to The SAGE Encyclopedia of Trans Studies, trans broken arm syndrome is a form of discrimination against transgender people. A 2021 survey by TransActual shows that 57% of transgender people in the United Kingdom put off seeing a doctor when they were ill. In 2014, 43% of transgender counselling clients in the UK said their counsellor "wanted to explore transgender issues in therapy even when this wasn't the reason they had sought help".
== Prognosis == Life expectancy is greatly reduced for people with Creutzfeldt–Jakob disease, and the average is less than six months. As of 1981, no one was known to have lived longer than 2.5 years after the onset of CJD symptoms. One of the world's longest survivors of vCJD was Jonathan Simms, a Northern Irish man who lived for 10 years after his diagnosis and received experimental treatment with pentosan polysulfate. Simms died in 2011.
Sources: en.wikipedia.org
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.
It is prohibited by the World Anti-Doping Agency as a hormone and metabolic modulator. Athletes who test positive for GW501516 can face sanctions, including suspensions and loss of results.
Cardarine is a common or trade-style name, while GW501516 is the research code for the same chemical entity. Some sources also use Endurobol or GSK-516. The names refer to the same compound, not distinct drugs.
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.