A practical reference on LC-MS/MS: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-07-27 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | PPARδ agonist | Not an anabolic steroid. |
| Common synonyms | GW501516, GW-1516 | Cardarine is an informal name. |
| Appearance | White to off-white powder | Typical for research-grade solid. |
| Solubility class | Poorly soluble in water; soluble in some organic solvents | Such as DMSO or ethanol in laboratory settings. |
| Typical storage temperature | Cool, dry, protected from light | Specific conditions vary by supplier and form. |
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.
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.
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.
== US rationale == In the United States, Trump administration officials have offered various and conflicting rationales for the war, such as to ward off an imminent Iranian threat, to pre-empt Iranian retaliation against US assets after an expected Israeli attack on Iran, to destroy Iran's missile and military capabilities, to prevent Iran from obtaining a nuclear weapon, to secure Iran's natural resources. Several statements were reportedly made by some United States officials such as the Secretary of Defense Pete Hegseth, justifying the action from a Christian religious perspective, some of which described the situation as a holy war. Trump also aimed to achieve regime change by bringing the Iranian opposition to power. Trump cheered on the Iranian protestors and urged them to "take over", promising that "HELP IS ON ITS WAY". However, more than five months into the conflict, this has been "one of the most glaring unfulfilled objectives" with many Iranians reporting a sense of betrayal. Trump later said that he never really believed that the uprising he encouraged would happen anyway.
==== Maintenance of the secret budget ==== During the electoral campaign, Lula repeatedly criticized the practice of the National Congress of allocating an increasingly relevant portion of the Union Budget to rapporteur's amendments, which critics called the secret budget, due to the lack of transparency regarding the amounts of each transfer and the names of the parliamentarians involved, and which was used by the Bolsonaro government to gather political support in parliament. After the election, Lula used his influence with the Supreme Federal Court to obtain a decision declaring the secret budget unconstitutional, by a narrow majority. At the time, the president of the Chamber of Deputies, Arthur Lira, alleged that he had seen Lula's interference in the vote of Ricardo Lewandowski, who after his retirement was invited to join the government as Minister of Justice. Despite the declaration of unconstitutionality, the National Congress continued in 2023 and 2024 with the same level of control over the budget, without transparency, replacing rapporteur's amendments with committee amendments and Pix amendments. In 2024, the non-transparent amendments will pay almost 25 billion reais.
== Recent work on homing peptides and nanomedicine == Ruoslahti's research group has developed a novel class of tumor-homing peptides that can be used to enhance delivery of drugs and nanoparticles to tumors. These tumor-penetrating peptides selectively home to tumor vessels, where they activate a transport pathway that delivers the peptide, and along with it drugs and even nanoparticles, through the wall of tumor blood vessels and deep into tumor tissue. Having bound to tumor vessels the peptide is cleaved and an amino acid sequence motif named the C-end rule or CendR motif (pronounced "sender") is exposed at the C-terminus of the peptide. Subsequent binding of the peptide to neuropilin-1 activates the CendR transport pathway into and through tumor tissue. The prototype tumor-penetrating peptide, iRGD, is in clinical trials in solid tumor patients tested as an enhancer of cancer therapies. This peptide recognizes many different types of cancers, and it can be used for tumor delivery of various payloads that are either coupled to the peptide, or given together with it. iRGD has also been shown to effectively deliver drugs to the placenta, which could aid in the treatment of slow fetal growth. Recently, in vivo phage screening has been used to identify peptides that target hypertensive pulmonary arteries, atherosclerosis, and diseases of the brain.
Sources: en.wikipedia.org
Introduced in 1974, this analyzer used light scattering, absorbance and cell staining to identify the five normal white blood cell types in addition to "large unidentified cells", a classification that usually consisted of atypical lymphocytes or blast cells. The Hemalog D could count 10,000 cells in one run, a marked improvement over the manual differential. In 1981, Technicon combined the Hemalog D with the Hemalog-8 analyzer to produce the Technicon H6000, the first combined complete blood count and differential analyzer. This analyzer was unpopular with hematology laboratories because it was labour-intensive to operate, but in the late 1980s to early 1990s similar systems were widely produced by other manufacturers such as Sysmex, Abbott, Roche and Beckman Coulter.
=== Alkylation of carboxylic acids and their salts === Trimethyloxonium tetrafluoroborate can be used for esterification of carboxylic acids under conditions where acid-catalyzed reactions are infeasible:
== Human proteins containing this domain == BMP binding endothelial regulator (BMPER) Cysteine-rich motor neuron 1 protein (CRIM1) Extracellular matrix protein 2 (ECM2) Fraser extracellular matrix complex subunit 1 (FRAS1) Neural EGFL like 1 (NELL1) Neural EGFL like 2 (NELL2) Peroxidasin like (PXDNL) Von Willebrand factor C and EGF domain-containing protein (VWCE) Von Willebrand factor (VWF)
Sources: en.wikipedia.org
He also coined technical terms such as “isodynamics,” “isoclines,” and “magnetic storm,” and was the first to describe the magnetic equator. Humboldt’s mapping and cartographic achievements set new standards for accuracy and integration. In Recueil d’observations astronomiques, d’opérations trigonométriques et de mesures barométriques, he presented maps that combined astronomical observations for latitude and longitude, triangulation, and barometric measurements of elevation. His maps of the Orinoco River, the Andes, the Valley of Mexico, and other regions provided unprecedented detail and clarity. In Mexico, he oversaw the production of a comprehensive map that synthesized political, economic, ethnographic, and physical information, setting a new standard for thematic maps. Humboldt’s Essai politique sur le royaume de la Nouvelle-Espagne (Political Essay on the Kingdom of New Spain) and Essai politique sur l’île de Cuba (Political Essay on the Island of Cuba) exemplify his approach to regional geography. These works combined exhaustive statistical data with economic, social, and physical analysis, offering the first modern regional studies of Mexico and Cuba. In Mexico, Humboldt’s assessments of mining resources, particularly silver, drew international attention and had significant economic repercussions. His Cuban essay was notable for its forceful condemnation of slavery. In both cases, Humboldt’s integration of field observations, statistical analysis, and critical commentary created a template for future regional and economic geography.
"Controversy surrounds both the drug study itself and the FDA approval," wrote NEJM editor-at-large Richard P. Wenzel, MD in 2002. The FDA approved the drug despite the advisory committee's split vote (10 to 10) due to concerns about the validity of the claimed efficacy and safety findings on the basis of a single trial. Eli Lilly spokeswoman Judy Kay Moore insisted that the company did not mastermind the ethics task force or steer the guideline-writing process. It was only a coincidence, Moore says, that the ethics task force and the Surviving Sepsis Campaign used the same P.R. firm, Belsito and Company.
== Musical style == In an interview with MTV in 2006, vocalist Taylor said that Come What(ever) May was a return to the roots of the band, stating it is "a lot more from the spirit of what the band started with in 1992". He noted that some songs were "very atmospheric" while others maintained "the hard rock and the heavy stuff". Jon Wiederhorn of MTV said that "for every thrash riff there's a tunefully grungy passage, for every flailing guitar line there's a rock-radio hook." When talking about the track "30/30-150", he said parts are "bludgeoning, barbed and heavy" while others are "soaring and triumphant" with the production of Raskulinecz helping to balance the album's heaviness with its radio-accessibility. Come What(ever) May's lyrics include themes of "pain, pleasure, happiness, and grief". The diversity in subjects is evident throughout the album; songs including "Come What(ever) May" were politically influenced while the track "Socio" is about "social anxiety attacks" that Taylor suffered. "Zzyzx Rd" is a love song written to Taylor's wife for helping him in his struggles against alcoholism and contemplation of suicide. "I've never written anything like that before, but it was very important for me to tell the world not only how much she saved me, but how much she means to me," said Taylor. Taylor said there is a common thread with the lyrics throughout the album, saying that they are "about never forgetting where you came from, who you are and why you do this."
14-3-3 proteins play an isoform-specific role in class switch recombination. They are believed to interact with the protein activation-induced cytidine deaminase in mediating class switch recombination. Phosphorylation of Cdc25C by CDS1 and CHEK1 creates a binding site for the 14-3-3 family of phosphoserine binding proteins. Binding of 14-3-3 has little effect on Cdc25C activity, and it is believed that 14-3-3 regulates Cdc25C by sequestering it to the cytoplasm, thereby preventing the interactions with CycB-Cdk1 that are localized to the nucleus at the G2/M transition. The eta isoform, YWHAH, is reported to be a biomarker (in synovial fluid) for rheumatoid arthritis. In a systematic review, 14-3-3η has been described as a welcome addition to the rheumatology field. The authors indicate that the serum based 14-3-3η marker is additive to the armamentarium of existing tools available to clinicians, and that there is adequate clinical evidence to support its clinical benefits in the management of patients diagnosed with rheumatoid arthritis (RA). 14-3-3 proteins bind to and sequester the transcriptional coregulators YAP/TAZ to the cytoplasm, inhibiting their function.
Sources: en.wikipedia.org
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.
No, cardarine is not a steroid. It is classified as a PPARδ agonist. Its structure and receptor target differ from anabolic steroids.
No regulatory agency has approved cardarine as a medicine. It was investigated in early research but development was discontinued. It is not available as a prescription drug.
Legal status varies by country. It is not approved as a medicine, and it is prohibited in sport. Some jurisdictions restrict import, sale, or possession.