GW501516 is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-03-06. Numbers and descriptions here follow the published literature rather than marketing material.
Cardarine is a common name for the investigational chemical GW501516, also written GW-1516. It was developed as a peroxisome proliferator-activated receptor delta agonist for metabolic conditions such as dyslipidemia. Early research focused on lipid handling and energy use in skeletal muscle and other tissues. The compound was never approved as a medicine. In public discussion, it is often grouped with performance-enhancing substances, although its receptor target differs from that of anabolic steroids or selective androgen receptor modulators. Regulatory and health authorities have issued warnings about its use.
GW501516 acts on PPARδ, a nuclear receptor that helps regulate fatty acid oxidation and energy homeostasis. In animal studies, activation of this receptor was associated with increased endurance and changes in lipid metabolism. Human trials examined effects on blood lipids and other metabolic markers, but the compound did not advance to approval. Rodent studies later reported tumors in multiple tissues at doses used in those experiments. Whether those findings translate to human risk remains uncertain, and the clinical relevance of the animal data is still debated.
Regulatory bodies treat GW501516 as a prohibited substance in competitive sport. The World Anti-Doping Agency added it to the prohibited list, and it falls under classes covering metabolic modulators and hormone-related agents. It is not approved by drug regulators for human use, and it is not a lawful dietary supplement. Products sold under the cardarine name may contain unlisted ingredients or different compounds. Because no approved product exists, quality and identity are not guaranteed by pharmaceutical manufacturing standards.
PPARδ is a nuclear receptor that influences transcription of genes involved in fatty acid oxidation, lipid transport, and energy homeostasis. GW501516 binds and activates this receptor with high selectivity relative to PPARα and PPARγ in laboratory assays. Activation alters expression of target genes in skeletal muscle, liver, and adipose tissue in animal models. The exact clinical consequences of these changes in humans remain incompletely characterized, and observed effects in animals do not establish therapeutic benefit or safety.
Published studies have examined GW501516 in animal models of obesity, insulin resistance, and exercise endurance. Early human trials reportedly ended, and development was discontinued after preclinical findings raised concerns about cancer in some rodent studies. Regulatory agencies have not approved cardarine for any medical use. Its availability through non-pharmaceutical channels raises questions about identity, purity, and legal status that are separate from its laboratory pharmacology. Those questions are often addressed through analytical testing rather than assumptions about product labels.
| Property | Value | Notes |
|---|---|---|
| Common name | Cardarine | Common internet and media name. |
| Research code | GW501516 | Also written GW-1516. |
| Drug class | PPARδ agonist | Not a selective androgen receptor modulator. |
| Development status | Discontinued | Clinical development halted after rodent cancer findings. |
| Regulatory status | Prohibited in sport | Listed by WADA; not approved as medicine. |
Safety discussions about cardarine frequently cite rodent carcinogenicity findings reported in the 2000s. In those studies, treated animals developed tumors at multiple sites, leading sponsors to discontinue clinical development. The relevance of these findings to humans has not been resolved, but they are a major reason the compound is not approved. Current literature emphasizes uncertainty about long-term effects and the risks of unregulated use. Regulators and health agencies have not established a safe human exposure level.
Cardarine is a synthetic compound also known as GW501516, GW-501516, and sometimes endurobol. It was developed as a selective agonist of peroxisome proliferator-activated receptor delta, a nuclear receptor involved in fatty acid oxidation and energy metabolism. The compound was studied in preclinical models for metabolic and cardiovascular conditions, but it did not become a marketed human medicine. In regulatory and anti-doping contexts, it is treated as a prohibited substance rather than a licensed medicine.
The pharmacological interest in cardarine centers on PPARδ activation and its downstream effects on lipid handling and mitochondrial function. In animal studies, PPARδ agonists have been associated with changes in exercise endurance and fatty acid utilization, though results vary by model and protocol. Human data remain sparse, and the absence of large controlled trials limits conclusions about efficacy. Researchers often describe the compound as a tool for probing PPARδ biology rather than a proven therapeutic agent.
Products sold as cardarine have been found to contain incorrect compounds, variable amounts, or no active ingredient at all. Independent testing is required to verify identity and purity. Common analytical approaches include high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance for structural confirmation. These methods can distinguish GW501516 from related PPAR agonists and from unrelated steroids. For regulators and researchers, such verification is central to interpreting both biological results and adverse event reports.
Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.
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.
Blue cod Parapercis colias Eastern freshwater cod Maccullochella ikei Mary River cod Maccullochella mariensis Murray cod Maccullochella peelii Potato cod Epinephelus tukula Black cod (Saddletail grouper) Epinephelus daemelii Sleepy cod Oxyeleotris lineolatus Trout cod Maccullochella macquariensis The notothen family, Nototheniidae, including: Antarctic cod Dissostichus mawsoni Dissostichus eliginoides, the Patagonian toothfish, is also marketed as "cod" Black cod Notothenia microlepidota Maori cod Paranotothenia magellanica
=== Broader negative impact on science === Just as the impact factor has attracted criticism for various immediate problems associated with its application, so has there also been criticism that its application undermines the broader process of science. Research has indicated that bibliometrics figures, particularly the impact factor, decrease the quality of peer review an article receives, cause a reluctance to share data, decrease the quality of articles, and a reduce the scope of publishable research. "For many researchers the only research questions and projects that appear viable are those that can meet the demand of scoring well in terms of metric performance indicators—and chiefly the journal impact factor." Furthermore, the process of publication and science is slowed down—authors automatically try to publish with the journals with the highest impact factor—"as editors and reviewers are tasked with reviewing papers that are not submitted to the most appropriate venues".
Sublingual administration of medications that are subject to a high first-pass effect with oral administration can result in improved bioavailability because the first pass through the intestines and liver is bypassed. As a result, sublingual estradiol has been found to result in estradiol levels and a ratio of estradiol to estrone that are substantially higher than oral estradiol. Maximal circulating levels of estradiol are as much as 10-fold higher with sublingual administration than with oral administration, and the absolute bioavailability of estradiol is approximately 5-fold higher. On the other hand, levels of estradiol fall rapidly with sublingual administration, whereas they remain elevated for a prolonged period of time with oral administration. This is due to the large circulating pool of hormonally inert estrogen conjugates with long half-lives that is reversibly generated with oral estradiol during first-pass metabolism, which serves as a metabolism-resistant and long-lasting reservoir for continuous reconversion back into estradiol. It is also responsible for the differences in ratios between sublingual estradiol and oral estradiol in terms of maximal estradiol levels (10:1) achieved and absolute bioavailability (5:1). A study in marmoset monkeys found that the bioavailability of sublingual estradiol was 10% of that of estradiol administered by intramuscular injection. After a dose of sublingual estradiol, levels of estrone start to slowly but progressively rise within 10 minutes.
==== Diagnosis ==== A bone mineral density test, such as dual-energy X-ray absorptiometry, is commonly used to assess bone strength, particularly in the hip and spine. Screening is generally recommended for women aged 65 and older, postmenopausal women with risk factors, and some men based on clinical evaluation.
Sources: en.wikipedia.org
==== Human evolution ==== During the long period between one and three million years ago, the Australopithecine (ancestors of modern humans) underwent several evolutionary changes. A long-term climate shift toward drier conditions promoted life changes from sedentary forest-dwelling with a primarily plant-based diet toward upright walking/running on open terrain and more meat consumption. One consequence of the shift to a culture that included more physically active hunting was a need for evaporative cooling from sweat, which to be functional, meant an evolutionary shift toward less body hair, as evaporation from sweat-wet hair would have cooled the hair but not the skin underneath. A second consequence was darker skin. The early humans who evolved in the regions of the globe near the equator had permanent large quantities of melanin in their skin, resulting in brown/black skin tones. For people with light skin tone, exposure to UV radiation induces the synthesis of melanin causing the skin to darken, i.e., sun tanning. Either way, the pigment can protect skin by dissipating up to 99.9% of absorbed UV radiation. In this way, melanin protects skin cells from UVA and UVB radiation damage that causes photoaging and the risk of melanoma, a cancer of melanin cells. Melanin also protects against photodegradation of the vitamin folate in skin tissue and, in the eyes, preserves eye health. The dark-skinned humans who had evolved in Africa populated the rest of the world through migration some 50,000 to 80,000 years ago.
CNS excitation: nervousness, agitation, anxiety, apprehension, tingling around the mouth (circumoral paraesthesia), headache, hyperesthesia, tremor, dizziness, pupillary changes, psychosis, euphoria, hallucinations, and seizures CNS depression with heavier exposure: drowsiness, lethargy, slurred speech, hypoesthesia, confusion, disorientation, loss of consciousness, respiratory depression, and apnoea. Cardiovascular: hypotension, bradycardia, arrhythmias, flushing, venous insufficiency, increased defibrillator threshold, edema, and/or cardiac arrest – some of which may be due to hypoxemia secondary to respiratory depression. Respiratory: bronchospasm, dyspnea, respiratory depression or arrest Gastrointestinal: metallic taste, nausea, vomiting, agita, and diarrhea Ears: tinnitus Eyes: local burning, conjunctival hyperemia, corneal epithelial changes/ulceration, diplopia, visual changes (opacification) Skin: itching, depigmentation, rash, urticaria, edema, angioedema, bruising, inflammation of the vein at the injection site, irritation of the skin when applied topically Blood: methemoglobinemia Allergy ADRs associated with the use of intravenous lidocaine are similar to the toxic effects of systemic exposure above. These are dose-related and more frequent at high infusion rates (≥3 mg/min). Common ADRs include headache, dizziness, drowsiness, confusion, visual disturbances, tinnitus, tremor, and/or paraesthesia.
=== 1947 === January 1: The American and British zones of control in Germany are united to form the Bizone, also known as Bizonia. February 10: Establishment of the neutral state Free Territory of Trieste. February 25: Prussia was de jure abolished. February 27: The February 28 incident begins in Taiwan lasting until mid-March. March 7: Paraguayan Civil War begins. March 12: President Harry Truman announces the Truman Doctrine starting with the giving of aid to Greece and Turkey in order to prevent them from falling into the Soviet sphere. April 16: Bernard Baruch, in a speech given during the unveiling of his portrait in the South Carolina House of Representatives, coins the term "Cold War" to describe relations between the United States and the Soviet Union. May 22: US extends $400 million of military aid to Greece and Turkey, signalling its intent to contain communism in the Mediterranean. June 5: Secretary of State George Marshall outlines plans for a comprehensive program of economic assistance for the war-ravaged countries of Western Europe. It would become known throughout the world as the Marshall Plan. July 11: The US announces new occupation policies in Germany.
=== Table of branding durations === Typical branding times with appropriately sized irons are as follows, with darker animals usually developing successful brands after the minimum application time. This table also summarizes experimental work carried out to assess freeze branding as a means of marking animals for scientific study.
That said, the residues of the C peptide that are conserved across species interact with similarly conserved residues on the A and B chains. Thus, it is hypothesized that these conserved residues are important for the functionality of mature insulin.
Sources: en.wikipedia.org
No. Cardarine is a PPARδ agonist, while selective androgen receptor modulators act on androgen receptors. The two classes differ in receptor target and downstream effects.
Preclinical rodent studies reported cancers, including liver and bladder tumors, at tested doses. The human relevance of those findings is uncertain, but development was discontinued. No approved human product resulted.
No. It remains an investigational compound without approved therapeutic labeling. Sports regulators prohibit its use, and health agencies have warned against consuming it.
Cardarine is commonly known as GW501516 or GW-1516. These names refer to the same synthetic compound. It is not a brand-name approved medicine.