anti-doping comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-05-08. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
GW501516 acts as an agonist at the peroxisome proliferator-activated receptor delta, a nuclear receptor that regulates gene expression. Activation shifts transcription toward genes involved in fatty acid uptake, oxidation, and energy expenditure. The compound does not bind the androgen receptor and therefore differs from anabolic steroids and SARMs. In rodent models, this metabolic shift has been linked to increased running endurance and reduced fat accumulation. The exact downstream pathways in humans remain incompletely characterized.
Early clinical research explored GW501516 for lipid disorders, obesity, and diabetes. Some short-term human studies reported changes in HDL cholesterol, LDL cholesterol, and triglycerides. The development program was discontinued after rodent studies showed dose-dependent tumor formation in multiple tissues, including liver, bladder, stomach, and skin. These findings raised concerns about long-term cancer risk in humans. Because human exposure data are limited, the clinical significance of the rodent tumors remains uncertain.
| 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 a common name for GW501516, an investigational compound developed in the 1990s for metabolic conditions. It acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in lipid and energy metabolism. The compound is frequently mislabeled as a selective androgen receptor modulator, or SARM, but its molecular target is different. GW501516 reached early clinical testing before development was discontinued. It has no approved therapeutic use in any country. The name cardarine is not a formal international nonproprietary name.
Regulatory treatment varies, but cardarine is not approved as a medicine. Sports authorities list GW501516 as a prohibited substance, and it is banned at all times under the World Anti-Doping Agency code. Many countries restrict sales for human consumption, while online vendors market it as a research chemical. Such products may lack purity data, and their actual contents can differ from the label. Purchasing or possessing cardarine may carry legal consequences depending on jurisdiction. The compound is not a dietary supplement ingredient in regulated markets.
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.
=== Reversible pulpitis === Reversible pulpitis is a mild to moderate inflammation caused by any momentary irritation or stimulant whereby no pain is felt upon the stimulants' removal. The pulp swells when the protective layers of enamel and dentine are compromised. Unlike irreversible pulpitis, the pulp gives a regular response to sensibility tests and inflammation resolves with management of the cause. No significant radiographic changes are present in the periapical region. Further examination is required to ensure that the dental pulp has returned to its normal state.
Agents of the Four Seasons (Japanese: 春夏秋冬代行者, Hepburn: Shunkashūtō Daikōsha) is a Japanese light novel series written by Kana Akatsuki (author of Violet Evergarden) and illustrated by Suoh. It began publication under ASCII Media Works' light novel imprint Dengeki Bunko in April 2021. A manga adaptation of the first part illustrated by Nappa Komatsuka began serialization in Hakusensha's shōjo manga magazine LaLa in July 2022. An anime television series adaptation of the first part produced by Wit Studio aired from March to June 2026.
== Biological function == Prolyl hydroxylase catalyzes the formation of hydroxyproline. The modification has a significant impact on the stability of collagen, the major connective tissue of the human body. Specifically, hydroxylation increases the melting temperature (Tm) of helical collagen by 16 °C, as compared to unhydroxylated collagen, a difference that allows the protein to be stable at body temperature. Due to the abundance of collagen (about one third of total protein) in humans, and the high occurrence of this modification in collagen, hydroxyproline is quantitatively the most abundant post-translational modification in humans. The enzyme acts specifically on proline contained within the X-Pro-Gly motif – where Pro is proline. Because of this motif-specific behavior, the enzyme also acts on other proteins that contain this same sequence. Such proteins include C1q, elastins, PrP, Argonaute 2, and conotoxins, among others.
Sources: en.wikipedia.org
A decreased renal function can be caused by many types of kidney disease. Upon presentation of decreased renal function, it is recommended to perform a history and physical examination, as well as performing a renal ultrasound and a urinalysis. The most relevant items in the history are medications, edema, nocturia, gross hematuria, family history of kidney disease, diabetes and polyuria. The most important items in a physical examination are signs of vasculitis, lupus erythematosus, diabetes, endocarditis and hypertension. A urinalysis is helpful even when not showing any pathology, as this finding suggests an extrarenal etiology. Proteinuria and/or urinary sediment usually indicates the presence of glomerular disease. Hematuria may be caused by glomerular disease or by a disease along the urinary tract. The most relevant assessments in a renal ultrasound are renal sizes, echogenicity and any signs of hydronephrosis. Renal enlargement usually indicates diabetic nephropathy, focal segmental glomerular sclerosis or myeloma. Renal atrophy suggests longstanding chronic renal disease.
Since Urbain was on the commission which made the decision, its objectivity could be questioned; furthermore, Welsbach protested that Urbain's spectral evidence was weak and argued that his rival's lutetium was very impure, but to no avail. After Urbain's names were recognized, neoytterbium was reverted to ytterbium. The controversy died down after 1910, only to be reignited with the discovery of element 72. Urbain claimed in 1911 to have discovered a new rare earth named celtium and identified it as element 72. However, Niels Bohr had demonstrated from his quantum theory that element 72 had to be a group 4 element and not a rare earth, and based on an idea by Fritz Paneth, Bohr's friend George de Hevesy worked with Dirk Coster to search for it in zirconium minerals. This they succeeded in doing, discovering hafnium in 1923. This discovery announcement, being in direct conflict with Urbain's celtium, ignited a controversy on element 72 throughout the 1920s; the resulting investigations on the nature of Urbain's celtium, since it was not the same as hafnium, reopened the case on element 71. The physicists Hans M. Hansen and Sven Werner, at Bohr's Copenhagen institute, found in 1923 that Welsbach's 1907 samples of cassiopeium had been pure element 71, while Urbain's 1907 lutecium samples only contained traces of element 71 and his 1911 samples identified as celtium were actually pure element 71 – confirming Welsbach's criticism.
=== Pharmacokinetics === The oral bioavailability of cannabidiol is approximately 6% in fasting state and 36.5–57.3% in fed-state in humans, while its bioavailability via inhalation is 11–45% (mean 31%). The oral bioavailability of cannabidiol varies based on several factors such as formulation, dose, and food intake. The sublingual bioavailability of cannabidiol is approximately 12–35%. The elimination half-life of cannabidiol in blood is 56–61 hours after oral doses twice per day over 7 days. Based on the pharmacokinetic analysis of long-term dosing of cannabidiol in humans, the terminal elimination half-life is estimated to be >134 hours. Cannabidiol is metabolized in the liver as well as in the intestines by cytochrome P450 enzymes.
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.
It targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not act primarily on androgen receptors. This distinction separates it from SARMs.