Everything below concerns GW501516. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-01-23. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 detect GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be used in some programs. Detection depends on factors such as dose, timing, metabolism, and the sensitivity of the assay. Published methods describe limits of detection in the low nanogram per milliliter range for related compounds. Exact detection windows are not fixed for all situations and remain an area of ongoing study.
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.
| 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 is a common name for GW501516, a synthetic compound developed in the 1990s through research collaborations involving GlaxoSmithKline. It belongs to a class of molecules known as peroxisome proliferator-activated receptor delta agonists. Early studies explored its effects on lipid metabolism and energy expenditure in animal models. The compound was never approved as a human medicine, and clinical development was discontinued. In the years since, it has appeared in fitness and bodybuilding communities as a performance-enhancing substance. Regulatory agencies classify it as an unapproved drug.
PPARδ is a nuclear receptor that regulates gene expression related to fatty acid oxidation, glucose homeostasis, and mitochondrial function. GW501516 binds to this receptor with high affinity and activates downstream signaling in skeletal muscle and other tissues. Animal studies reported increased endurance and altered fuel preference, but human data remain limited and inconsistent. The precise relationship between receptor activation and observed physiological changes is still an area of active investigation. Researchers have also examined whether the compound affects inflammation or cell proliferation. No approved therapeutic indication exists for cardarine.
In laboratory settings, cardarine is studied as a tool compound for probing PPARδ biology. Published experiments often use cell cultures, rodent models, or isolated tissues. Some investigations focus on metabolic effects, while others assess potential risks such as carcinogenicity observed in long-term animal studies. Because human trials are sparse, most knowledge comes from preclinical work and adverse event reports. Scientific literature frequently notes the gap between animal findings and human outcomes. The compound is not a dietary supplement and is not intended for human consumption.
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.
=== Record label signings and dispute over Kendrick Lamar's lyrics === Sometime after deciding to return, Clipse signed to Def Jam Recordings, which had already been Pusha T's label as a solo artist from when GOOD Music was a Def Jam imprint. Let God Sort Em Out was delayed significantly from a planned 2024 release when Def Jam and its parent company Universal Music Group wanted a guest verse by Kendrick Lamar to be censored or removed, initially reported to be because both he and Pusha T have had feuds with Drake, leading to the exchanging of diss tracks in 2018 and 2024, respectively; Universal were said to be uncomfortable with the "optics" of the situation, and Drake's feud with Lamar would eventually result in a lawsuit by Drake against them. It was later clarified that the official reason was use of the phrase "Trump card" in the lyrics and concerns of conflict with United States President Donald Trump, although Pusha T personally believed that this was merely an excuse, as he claimed to have been censored by Def Jam numerous times since 2018 over lyrics that could be perceived as Drake disses. The signing wasn't announced until October 2024. Journalist Elias Leight wrote that the duo was already signed as of "early" 2024. Music industry executive Brian Zisook publicly claimed that Clipse was already under Def Jam c. June 2023. Clipse refused to censor or remove the verse.
In the anterior pituitary, the term "acidophil" is used to describe two different types of cells which stain well with acidic dyes. Somatotrophs, which secrete growth hormone (a peptide hormone) Lactotrophs, which secrete prolactin (a peptide hormone) When using standard staining techniques, they cannot be distinguished from each other (though they can be distinguished from basophils and chromophobes), and are therefore identified simply as "acidophils". Eosinophilic Acidophile (histology) Basophilic Chromophobe cell Melanotroph Chromophil Basophil cell Oxyphil cell Oxyphil cell (parathyroid) Pituitary gland Neuroendocrine cell
== Oxygen-15 == Oxygen-15 (half-life 122.27 seconds) is the most stable radioisotope of oxygen, decaying by positron emission to nitrogen-15. It is thus the isotope of oxygen used in positron emission tomography (PET). It can be used in, among other things, water for PET myocardial perfusion imaging and for brain imaging. It is produced for this application through deuteron bombardment of nitrogen-14 using a cyclotron.
Sources: en.wikipedia.org
This is an example of the Nernst equation. The potential is known as a reduction potential. Standard electrode potentials are available in a table of values. Using these values, the actual electrode potential for a redox couple can be calculated as a function of the ratio of concentrations. The equilibrium potential for a general redox half-reaction (See #Equilibrium constant above for an explanation of the symbols)
=== Immune system === Vitamin D receptors are found in cell types involved in immunity. Functions are not understood. Some autoimmune and infectious diseases are associated with vitamin D deficiency, but either there is no evidence that supplementation has a benefit or not, or for some, evidence indicating there are no benefits.
=== UN treaties and US influence === The three UN drug control conventions, adopted by over 180 countries, provide a legal framework for cooperation between countries. Each state is obligated to incorporate the treaty provisions in their domestic laws. While there is a degree of interpretative flexibility, "each of the treaties encourages – and often requires – that member countries put in place strong domestic penal provisions" to deal with illicit drugs; punitive policies have been the common approach. The US, emerging as the dominant power after WWII, exerted considerable influence over how the conventions were adopted by other nations, promoting a prohibitionist and criminalizing view. Historically, the US has been "the key player in most multilateral negotiations" and the prohibitionist approach "derives largely from U.S. policy – the various forms, past and present, of the U.S. 'war on drugs'". US economic power is focused on the war on drugs through the Foreign Assistance Act (FAA). Enacted in 1961, the FAA integrated various federal foreign aid initiatives under the new US Agency for International Development (USAID), and has remained the core legislation governing foreign financial assistance. In 1972, reacting to concerns over illicit drugs from foreign sources, Congress added an "International Narcotics Control" chapter to the FAA, which allowed the president to enter into agreements and provide assistance for counternarcotic activities in foreign countries.
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.
Legal status varies by country, but cardarine is not approved as a medicine in major jurisdictions. It is often sold as a research chemical, a category that may not be lawful for human use. Buyers should check local laws and product labels carefully.