Nuclear receptor raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-09-10 and is reviewed periodically as new material appears.
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.
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.
| 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. |
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 is a common name for GW501516, also GW-1516, a synthetic compound developed as a peroxisome proliferator-activated receptor delta (PPARδ) agonist. It belongs to a class of agents that modulate gene transcription related to lipid and energy metabolism. The compound was studied in preclinical and early clinical research for metabolic and cardiovascular conditions, but it did not progress to approved therapeutic use. Its name appears in fitness and sports contexts despite not being approved as a 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.
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.
It was initially thought that resistance of 4-aminosalicylic acid came from a mutation affecting dihydrofolate reductase (DHFR). However, it was discovered that it was caused by a mutation affecting the dihydrofolate synthesis (DHFS) enzyme activity. The mutations of isoleucine 43, arginine 49, serine 150, phenylalanine 152, glutamate 153, and alanine 183 were found to affect the binding pocket of the dihydrofolate synthase enzyme. This will reduce the ability for HO-H2Pte to bind to DHFS so that less of OH-H2PteGlu is made.
Subject of research: synthesis of organophosphorous and organoelement compounds, study of their spatial and electronic structure, intramolecular electronic interactions, reaction capacity and mechanism of reactions. Arkady N. Pudovik corresponding member of Russian Academy of Science worked at this department since its opening (1948) until his death (February 2006) he was the founder of the department of High Molecular and Organoelement Compounds and held the position of Head of department until 1987. Current head of the Department – Corresponding Member of the Academy of Sciences of the Republic of Tatarstan, Professor Vladimir I. Galkin, doctor of Science in chemistry. The Department conducts research in the following fields:
To determine the optimal length of the stem, researchers modified its length and observed how quickly termination occurred. When the length of the stem was lengthened or shortened from the standard length of 8–9 base pairs, termination was less efficient, and if the changes were great enough, termination ceased completely. Experiments determined that if an oligonucleotide sequence that is identical to the downstream portion of the stem is present, it will base pair with the upstream portion. This creates a structure that is analogous to the native stem-loop structure but is missing the loop at the end. Without the presence of the loop, intrinsic termination is still able to occur. This indicates that the loop is not inherently necessary for intrinsic termination. Generally, the absence of the uracil-rich sequence following the stem-loop will result in a delay or pause in transcription, but termination will not cease completely.
Interpretation for secondary adrenal insufficiency In secondary adrenal insufficiency, due to exogenous steroid administration suppressing pituitary production of ACTH or due to primary pituitary disorder causing insufficient ACTH production, the adrenal glands will atrophy over time and cortisol production will fall and patients will fail stimulation testing. Early in the development of secondary adrenal insufficiency, the adrenals may not have atrophied and can still stimulate, resulting in a normal cosyntropin stimulation test. If secondary adrenal insufficiency is diagnosed, the insulin tolerance test (ITT) or the CRH (corticotropin-releasing hormone) stimulation test can be used to distinguish between a hypothalamic (tertiary) and pituitary (secondary) cause but is rarely used in clinical practice. Measuring a morning, fasting ACTH level helps assess for the etiology of adrenal insufficiency. Interpretation for primary adrenal insufficiency and Addison's disease ACTH will be high – usually well above upper limits of reference range.
The Department works at the intersection of organic chemistry (chemistry of natural products, chemistry of macrocyclic compounds, chemistry of elementorganic compounds), supramolecular chemistry (solution and self-process chemistry) and molecular biology. The head of the Department is Professor Igor S. Antipin, a corresponding member of the Russian Academy of Science, Doctor of Chemistry. The Department conducts research in the following fields:
Sources: en.wikipedia.org
The 43S preinitiation complex (43S PIC) is a ribonucleoprotein complex that exists during an early step of eukaryotic translation initiation. The 43S PIC contains the small ribosomal subunit (40S) bound by the initiation factors eIF1, eIF1A, eIF3, and the eIF2-Met-tRNAiMet-GTP ternary complex (eIF2-TC). The 43S is an important intermediate complex during cap-dependent initiation in translation. In the canonical model of translation initiation, the 43S PIC is pre-formed as a stable complex and recruited to the 5' cap of eukaryotic messenger RNAs (mRNAs) by the eIF4F complex. The 43S PIC then "scans" in the 5' --> 3' direction along the mRNA in an ATP-dependent fashion (via eIF4A and/or other RNA helicases such as Ded1/DDX3 and DHX29) to locate the start codon. Start codon recognition occurs through base-pairing between the Met-tRNAiMet and AUG in the ribosomal P-site and a number of associated changes, and is followed by joining of the large 60S ribosomal subunit to form the 80S ribosome.
Interpretation for primary aldosterone deficiency The aldosterone response in the ACTH stimulation test is blunted or absent in patients with primary adrenal insufficiency including Addison's disease. The base value is usually in the mid-teens or less and rise to less than double the base value thus indicating primary hypoaldosteronism (sodium low, potassium and renin enzyme will be high) and is an indicator of primary adrenal insufficiency or Addison's disease.
It is an amino alcohol and a bioactive sphingoid. Its distinctive trait is that the terminal hydroxy group has been replaced by hydrogen. It possesses antineoplastic properties, appearing to inhibit the proliferation of some kinds of cancer. This sphingoid base can be found, in general, in low levels, in animal cells, and at higher concentrations in the cell membranes of certain bacteria, including Bacteroides species common to the animal gut microbiome—suggesting this as a potential source of these compounds in circulation. It was found for the first time in a marine organism, in which context it is known as spisulosine. It is known by other names such as ES-285. The molecular weight of this compound is 285,5 g/mol and its molecular formula is C18H39NO, which means it has 18 carbons.
Josh Allen became the first player to score a rushing touchdown, a receiving touchdown and multiple passing touchdowns in a single game. Bobby Wagner extended his streak of recording 100 tackles in a season to 13 years. He is the second player to record the feat, joining London Fletcher. Jayden Daniels became the first rookie to complete 80 percent of his passes, throw three touchdowns, and run for a touchdown in a single game. Jameis Winston became the first player in the Super Bowl era to have at least 400 passing yards, four passing touchdowns and two interceptions returned for touchdowns in a game. Justin Herbert became the third player to have at least 10 consecutive games without interception (minimum 15 attempts per game), joining Tom Brady and Derek Carr. The Pittsburgh Steelers tied the record for most consecutive seasons finishing with a winning percentage of .500 or better, with 21. They share the record with the Dallas Cowboys, who did so from 1965 to 1985. The Cincinnati Bengals tied the single-season record for most games lost while scoring at least 30 points, with four. They share the record with the 2002 Kansas City Chiefs. Week 14
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. It is not approved as a medicine, and it is prohibited in sport. Some jurisdictions restrict import, sale, or possession.