The short version of LC-MS/MS fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-05-25. Anything still debated is marked as such rather than presented as settled.
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.
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 |
|---|---|---|
| Common synonyms | GW501516, GW-501516, GW 501516, endurobol | Names vary in research and anti-doping documents. |
| Chemical class | Synthetic PPARδ agonist | Small-molecule nuclear receptor ligand. |
| CAS Registry Number | 317318-70-0 | Identifier commonly associated with GW501516. |
| Appearance | White to off-white powder | Typical for purified research material. |
| Solubility | Low in water; soluble in DMSO and ethanol | Organic solvents are common for laboratory stock solutions. |
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.
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.
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.
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.
== Location and campus == The college consists of an administrative block and self-contained blocks for the basic clinical departments. The college maintains a library, computer centre and a reading room.
=== Rule of 13 === The Rule of 13 is a simple procedure for tabulating possible chemical formula for a given molecular mass. The first step in applying the rule is to assume that only carbon and hydrogen are present in the molecule and that the molecule comprises some number of CH "units" each of which has a nominal mass of 13. If the molecular weight of the molecule in question is M, the number of possible CH units is n and
As an AAS, ethylestrenol is an agonist of the androgen receptor (AR), similarly to androgens like testosterone and dihydrotestosterone (DHT). It has low estrogenic activity (via aromatization into ethylestradiol following transformation into norethandrolone), strong progestogenic activity, and a high ratio of anabolic to androgenic activity, similarly to other nandrolone derivatives. Like other 17α-alkylated AAS, ethylestrenol has a risk of hepatotoxicity.
1 February – Billy Galligan, 86, hurler (Charleville, Blackrock, Claughaun, Avondhu, Cork senior team). 6 February – Niamh Bhreathnach, 77, politician, TD (1992–1997), Minister for Education (1993–1994 and 1994–1997). 7 February – Richard Kell, 95, poet, composer and teacher. 11 February – Séamus Ryan, hurler (Cappamore, Limerick senior team). 12 February James Flynn, 57, film and television producer (Vikings, The Last Duel, The Banshees of Inisherin). Theo Dunne, 85, footballer (Shelbourne) and manager (UCD). 13 February – Deirdre Purcell, 77, actress, journalist, broadcaster and author. 18 February – David G. O'Connell, 69, Roman Catholic prelate, Auxiliary Bishop of Los Angeles (2015–2023). 22 February Mick Burns, 85, hurler (Nenagh Éire Óg, Tipperary senior team, Munster). Dermot Kelly, 90, hurler (Claughaun, Limerick senior team, Munster). 24 February – Tom Tierney, 46, rugby union player (Garryowen, Munster, Leicester, national team) and coach (women's national team). 26 February Tony O'Donoghue, 86, athlete and broadcaster. Kieron Wood, 73, barrister, journalist and writer. 28 February Brian O'Brien, 83, rugby union player (Shannon, Munster, national team) and manager (Shannon, Munster, national team). Jimmy Hatton, 88, Gaelic footballer and hurler (Kilcoole, Wicklow senior teams) and referee.
Sources: en.wikipedia.org
MiaB introduces a methylthio group to the isopentenylated A37 derivatives in the tRNA of S. Typhimurium and E. coli by utilizing one SAM molecule to generate 5'-dAdo radical to activate the substrate and a second SAM to donate a sulfur atom to the substrate. RimO is responsible for post-translational modification of Asp88 of the ribosomal protein S12 in E. coli. The crystal structure sheds light on the mechanistic action of RimO. The enzyme catalyzes pentasulfide bridge formation linking two Fe-S clusters to allow for sulfur insertion to the substrate. eMtaB is the designated methylthiotransferase in eukaryotic and archaeal cells. eMtaB catalyzes the methylthiolation of tRNA at position 37 on N6-threonylcarbamoyladenosine. A bacterial homologue of eMtaB, YqeV has been reported and suggested to function similarly to MiaB and RimO.
=== Balance of payments between the states === In 2019, residents and businesses in only 8 states contributed, as a whole, more money to the federal treasury than they received in services. Per capita, these were Connecticut ($1,614), Massachusetts ($1,439), New York ($1,172), New Jersey ($1,163), Minnesota ($336), Colorado ($239), California ($168), and Utah ($130). All other states received more in services than taxpayers there contributed, especially in (per capita) Kentucky ($14,153), Virginia ($13,096), and Alaska ($10,144).
== Analysis == Ligation may also serve as a DNA analysis method. Some techniques employ rolling circle amplification. The most notable of these is described by Smolina et al., 2007 & Smolina et al., 2008 using fluorescence in situ hybridization and peptide nucleic acids. They developed and employed this technique for analyses of bacterial chromosomes.
=== Ectendomycorrhiza === Although the Hartig net forms outside the root cells, penetration of plant cortical cells occasionally occurs. Many species of ectomycorrhizal fungi can function either as ectomycorrhizas or in the penetrative mode typical of arbuscular mycorrhizas, depending on the host. Because these associations represent a form of symbiosis in between arbuscular mycorrhizas and ectomycorrhizas, they are termed ectendomycorrhizas.
A more intuitive characteristic of exponential decay for many people is the time required for the decaying quantity to fall to one half of its initial value. (If N(t) is discrete, then this is the median life-time rather than the mean life-time.) This time is called the half-life, and often denoted by the symbol t1/2. The half-life can be written in terms of the decay constant, or the mean lifetime, as:
Sources: en.wikipedia.org
Cardarine is an investigational synthetic compound that acts as a PPARδ agonist. It is also known as GW501516 and has been studied mainly in preclinical research. It is not an approved medicine.
No. Cardarine is not a steroid hormone; it targets the nuclear receptor PPARδ. Its classification in anti-doping rules differs from anabolic steroids, though it remains prohibited in sport.
Early rodent studies reported tumor formation at multiple sites, which raised safety concerns. Sponsors stopped clinical development, and no approved human product exists.
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.