A practical reference on fatty acid oxidation: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
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.
Clinical development stopped after rodent studies showed tumors at multiple sites. Whether those findings predict human cancer risk remains an open question, but they led sponsors to discontinue programs. Human safety data are limited to small, short-term studies that were not designed to assess cancer risk. Reported effects in those studies included changes in blood lipids, but the evidence is insufficient for medical use. Long-term consequences of nonmedical use are not well characterized. Questions about dose, duration, and individual susceptibility remain unresolved.
Activation of PPARδ changes transcription of genes involved in fatty acid transport, mitochondrial function, and skeletal muscle fuel preference. In rodent studies, pharmacological PPARδ activation was associated with increased endurance and altered body composition. These findings generated interest in performance enhancement, but species differences and study designs limit direct extrapolation to humans. Small human trials were conducted in the 2000s and later discontinued. The extent to which cardarine produces similar metabolic or performance effects in people remains an open question.
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
Cardarine is a common name for GW501516, a synthetic compound studied for its effects on lipid and glucose metabolism. It functions as an agonist at peroxisome proliferator-activated receptor delta, or PPARδ, a nuclear receptor that influences gene expression. The molecule is not a steroid, nor is it a selective androgen receptor modulator. It is also known in research and sports literature as GW-501516 and endurobol. Early laboratory work examined its metabolic activity in cell cultures and animal models.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | GW501516; GW-1516; endurobol | GW501516 is the research code |
| Drug class | PPARδ agonist | Not a selective androgen receptor modulator |
| Molecular formula | C21H18F3NO3S2 | Established chemical formula |
| Molar mass | 453.5 g/mol | Calculated from the formula |
| Regulatory status | Prohibited in sport; not approved as medicine | Status varies by country |
Cardarine can be detected in biological samples and product materials using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The method separates compounds by chromatography and identifies them by mass-to-charge transitions, allowing low-level detection in urine or blood. Sample preparation often involves enzymatic hydrolysis, solid-phase extraction, or protein precipitation. Certified reference materials and isotope-labeled internal standards improve quantification. Detection windows depend on metabolism, matrix, and assay sensitivity, so no single universal window applies.
Regulatory treatment of cardarine differs by context and jurisdiction. In competitive sport, the World Anti-Doping Agency lists PPARδ agonists, including GW501516, as prohibited at all times. Outside sport, it lacks approval as a prescription medicine in major drug markets, and products sold for human consumption may be treated as unapproved drugs. Some countries also restrict importation or sale through general consumer protection and medicines laws. These classifications affect availability, testing, and legal risk without establishing therapeutic value.
Because cardarine is not an approved medicine, no pharmacopeial monograph defines its identity, purity, or storage requirements. Laboratories typically rely on in-house methods and reference standards when testing materials labeled as GW501516. Certificates of analysis may report purity and identity for a specific batch, but their scope varies and they do not guarantee safety or legal status. Independent verification can include high-performance liquid chromatography, mass spectrometry, nuclear magnetic resonance, and elemental analysis. The distinction between research chemical labeling and human use is significant because quality standards and oversight differ.
Laboratory studies have examined GW501516 in cell cultures and rodents for conditions such as dyslipidemia, insulin resistance, and obesity. Some trials in humans were initiated, but development was discontinued after preclinical findings raised concerns about cancer in certain models. Those findings do not prove that the compound causes cancer in people, but they contributed to regulatory caution. Later reviews often describe the evidence as preliminary and insufficient for assessing long-term safety.
In the fitness and bodybuilding literature, cardarine is frequently discussed as an endurance agent or fat-loss compound, although such claims are not supported by robust clinical evidence. Online descriptions often mix animal data, user anecdotes, and marketing language. Researchers who study PPARδ agonists distinguish between receptor activation in controlled experiments and unsupervised use of unverified products. The latter introduces unknown purity, dose, and interactions, making reported experiences difficult to interpret scientifically.
GW501516 acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in transcription of genes related to lipid handling and energy use. Activation of PPARδ can shift skeletal muscle toward greater fatty acid oxidation in animal models, which is one reason it drew interest for metabolic disease and exercise research. The exact downstream effects depend on tissue, species, dose, and duration. Human data are sparse, so many proposed benefits remain hypotheses rather than established clinical outcomes.
Distal membrane-arm assembly complex protein 1 is a protein that in humans is encoded by the DMAC1 gene (previously TMEM261). TMEM261 is also known as C9ORF123 and DMAC1, Chromosome 9 Open Reading Frame 123 and Transmembrane Protein C9orf123 and Distal membrane-arm assembly complex protein 1. TMEM261 is located at 9p24.1, its length is 91,891 base pairs (bp) on the reverse strand. Its neighbouring gene is PTPRD located at 9p23-p24.3 also on the reverse strand and encodes protein tyrosine phosphatase receptor type delta. TMEM261 has 2 exons and 1 intron, and 6 primary transcript variants; the largest mRNA transcript variant consisting of 742bp with a protein 129 amino acids (aa) in length and 13,500 daltons (Da) in size, and the smallest coding transcript variant being 381bp with a protein 69aa long and 6,100 Da in size. TMEM261 is a protein consisting out of 112 amino acids, with a molecular weight of 11.8 kDa. The isoelectric point is predicted to be 10.2, whilst its posttranslational modification value is 9.9.
Encapsulin shells compromise icosahedral complexes (12 vertices, 20 faces, 30 edges) formed as a result of self-assembly of protomers. These encapsulin shells have diameters between 24 and 42 nm and are defined by the HK97-fold of their shell protein. The HK97-fold protomer has a roughly triangular shape and consists of three conserved domains: the axial domain, the peripheral domain, and the extended loop. The size and symmetry of the capsid are defined by a triangulation number (T), which determines the number of subunits in the assembly. For example: T = 1 encapsulins (Thermotoga martima) consist of 60 protomers. T = 3 encapsulins (Pyrococcus furiosus) consist of 180 protomers. T = 4 encapsulins (Quasibacillus thermotolerans) consist of 240 protomers.
Streptomyces isolates have yielded the majority of human, animal, and agricultural antibiotics, as well as a number of fundamental chemotherapy medicines. Streptomyces is the largest antibiotic-producing genus of Actinomycetota, producing chemotherapy, antibacterial, antifungal, antiparasitic drugs, and immunosuppressants. Streptomyces isolates are typically initiated with the aerial hyphal formation from the mycelium.
Starch is made of about 70–80% amylopectin by weight, though it varies depending on the source. For example, it ranges from lower percent content in long-grain rice, amylomaize, and russet potatoes to 100% in glutinous rice, waxy potato starch, and waxy corn. Amylopectin is highly branched, being formed of 2,000 to 200,000 glucose units. Its inner chains are formed of 20–24 glucose subunits. Dissolved amylopectin starch has a lower tendency of retrogradation (a partial recrystallization after cooking—a part of the staling process) during storage and cooling. For this main reason, the waxy starches are used in different applications mainly as a thickening agent or stabilizer.
Sources: en.wikipedia.org
In an effort to prevent incidents such as the disappearance of Malaysia Airlines Flight MH370, a new standard has been issued requiring all commercial aircraft to report their position every 15 minutes to air traffic controllers regardless of the country of origin. Introduced in 2016 by the ICAO, the regulation has no initial requirement for any new aircraft equipment to be fitted. The standard is part of a long-term plan, called the Global Aeronautical Distress and Safety System (GADSS), which will require new aircraft to be equipped with data broadcast systems that are in constant contact with air traffic controllers. The GADSS is similar to the Global Maritime Distress and Safety System (GMDSS) used for maritime safety.
ASH1L is ubiquitously expressed throughout the body. In the brain, ASH1L is expressed across brain areas and cell types, including excitatory and inhibitory neurons, astrocytes, oligodendrocytes, and microglia. ASH1L also does not appear to show specificity to any brain region. In humans, ASH1L mRNA expression levels are fairly equal across all regions of cortex. Similarly, in mice, ASH1L protein is highly expressed in the hippocampus, thalamus, hypothalamus, motor cortex, and basolateral amygdala. In humans, ASH1L expression peaks prenatally and decreases after birth, with a second peak in expression towards adulthood. In mouse, ASH1L is expressed in the developing central nervous system as early as embryonic day 8.5 and is still expressed throughout the adult mouse brain. Overall, the expression of ASH1L in the brain is spatially and temporally broad.
Pyocyanin inactivates catalase by reducing its gene’s transcription as well as directly targeting the enzyme itself. Glutathione is an important antioxidant modulated by pyocyanin. In particular the pool of the reduced form is depleted while the oxidised form is promoted by hydrogen peroxide which is not dismutated by catalase. In the cystic fibrosis lung, intracellular pyocyanin converts molecular oxygen to the superoxide free radical by oxidizing NADPH to NADP+. This has a doubly negative effect on the lungs. Firstly, the NADPH used by pyocyanin depletes the available substrate for the reaction catalysed by the NADPH oxidase enzyme. Secondly, the superoxide radical generated can inhibit cytokines, such as IL-4, IL-13 and IFN-γ, which usually upregulate NADPH oxidase. When the lung is confronted with pyocyanin, an increased concentration of catalase and superoxide dismutase is seen in order to deal with the barrage of radicals being produced.
Sources: en.wikipedia.org
Pyzdek, T, "Quality Engineering Handbook", 2003, ISBN 0-8247-4614-7 De Feo, J. A., "Juran's Quality Handbook", 2016, ISBN 978-1-25964-361-3 ASTM E105 Standard Practice for Probability Sampling of Materials ASTM E122 Standard Practice for Calculating Sample Size to Estimate, With a Specified Tolerable Error, the Average for Characteristic of a Lot or Process ASTM E141 Standard Practice for Acceptance of Evidence Based on the Results of Probability Sampling ASTM E1402 Standard Terminology Relating to Sampling ASTM E1994 Standard Practice for Use of Process Oriented AOQL and LTPD Sampling Plans ASTM E2234 Standard Practice for Sampling a Stream of Product by Attributes Indexedby AQL Sampling procedures for inspection by attributes, ISO 2859-1:1999 Sampling procedures for inspection by attributes, JIS Z 9015-1:2006 Acceptance Sampling Calculators (SQC Online) (A subscription fee is required to use the calculators. The "free" calculations have locked features.)
The latest development in the medical treatment of acromegaly is the use of growth hormone receptor antagonists. The only available member of this family is pegvisomant (Somavert). By blocking the action of the endogenous growth hormone molecules, this compound is able to control the disease activity of acromegaly in virtually everyone with acromegaly. Pegvisomant has to be administered subcutaneously by daily injections. Combinations of long-acting somatostatin analogues and weekly injections of pegvisomant seem to be equally effective as daily injections of pegvisomant. Paltusotine (Palsonify) was approved for medical use in the United States in September 2025.
Dyneins, one of the three major classes of motor protein, are AAA proteins which couple their ATPase activity to molecular motion along microtubules. The AAA-type ATPase Cdc48p/p97 is perhaps the best-studied AAA protein. Misfolded secretory proteins are exported from the endoplasmic reticulum (ER) and degraded by the ER-associated degradation pathway (ERAD). Nonfunctional membrane and luminal proteins are extracted from the ER and degraded in the cytosol by proteasomes. Substrate retrotranslocation and extraction is assisted by the Cdc48p(Ufd1p/Npl4p) complex on the cytosolic side of the membrane. On the cytosolic side, the substrate is ubiquitinated by ER-based E2 and E3 enzymes before degradation by the 26S proteasome.
The human ADM gene is localized to a single locus on Chromosome 11 with 4 exons and 3 introns. The ADM gene initially codes for a 185-amino acid precursor peptide, that can be differentially excised to form a number of peptides, including an inactive 53-amino acid AM, e PAMP, adrenotensin and ADM95-146. Mature human ADM is activated to form a 52-amino acid, 6-amino acid ring, that shares moderate structural similarity to the calcitonin family of regulatory peptides (calcitonin, CGRP and amylin). Circulating ADM consists of both the amidated active form (15%) and the glycated inactive form (85%). It has a plasma half-life of 22min, a mean clearance rate of 27.4 mL/kg/min, and an apparent volume of distribution of 880 ± 150 mL/kg. Adrenomedullin consists of 52 amino acids, has 1 intramolecular disulfide bond, and shows a slight homology with the calcitonin gene-related peptide (CGRP). The precursor, called preproadrenomedullin, consists of 185 amino acids and can be cleaved by plasma kallikrein at the Lys-Arg and Arg-Arg sites. By RNA-blot analysis, human adrenomedullin mRNA was found to be expressed in all tissues, and most highly expressed in the placenta, fat cells, lung, pancreatic islets, smooth muscle, and skin.
Sources: en.wikipedia.org
No. Cardarine is GW501516, a PPARδ agonist, while SARMs act on androgen receptors. The two classes are often grouped in informal discussions despite different mechanisms.
No. It has no approved medical indication in any country. Regulatory agencies have not cleared it for treatment or prevention of any condition.
Early clinical work stopped after rodent carcinogenicity findings. Those animal results raised concerns about long-term human risk, although direct human evidence is lacking. The human relevance of the tumors remains an open scientific question.
Cardarine is a common name for GW501516, a synthetic PPARδ agonist. It is not a steroid or a selective androgen receptor modulator. It was developed and studied as a research compound for metabolic pathways.