Certificate of analysis is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-01-29. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| 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 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.
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.
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.
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.
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.
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.
== Properties == Proline and its higher homolog pipecolic acid affect the secondary structure of protein. D-alpha-amino acid - L-alpha-amino acid sequence can induce beta hairpin. It suggested that acyclic secondary amino acids are more flexible than cyclic secondary amino acids in protein by replacement of pipecolic acid by N-methyl-L-alanine in efrapeptin C. Ninhydrin tests of proline and hydroxyproline give yellow results. In enzymology, a N-methyl-L-amino-acid oxidase is an oxidase of a subtype of secondary amino acids.
=== Libraries and archives === The main library is located in the city centre, named after the writer Armand Salacrou. It has branches in all districts. A new multimedia library at the "Volcano" is being refurbished for 2014. Thousands of references are available in specialized libraries in the Higher School of Art, the Museum of André Malraux, and the Natural History Museum. Medieval manuscripts and Incunables are conserved at the public library. The archives of the city, at the Fort of Tourneville, possesses documents from the 16th to the 20th centuries.
The large spectrum of cancer phenotypes due to mutations in the TP53 gene is also supported by the fact that different isoforms of p53 proteins have different cellular mechanisms for prevention against cancer. Mutations in TP53 can give rise to different isoforms, preventing their overall functionality in different cellular mechanisms and thereby extending the cancer phenotype from mild to severe. Recent studies show that p53 isoforms are differentially expressed in different human tissues, and the loss-of-function or gain-of-function mutations within the isoforms can cause tissue-specific cancer or provide cancer stem cell potential in different tissues. TP53 mutation also hits energy metabolism and increases glycolysis in breast cancer cells.
The request for a sequel to The Hobbit prompted Tolkien to begin what ultimately developed into his magnum opus: the epic high-fantasy novel The Lord of the Rings. Written in stages and heavily expanded from its original scope, the novel was published in three volumes between 1954 and 1955. Tolkien spent more than ten years writing the primary narrative and appendices for The Lord of the Rings, during which time he received the constant support of the Inklings, in particular his closest friend C. S. Lewis, the author of The Chronicles of Narnia. Both The Hobbit and The Lord of the Rings are set against the background of The Silmarillion, but in a time long after it. Tolkien at first intended The Lord of the Rings to be a children's tale in the style of The Hobbit, but it quickly grew darker and more serious in the writing. Though a direct sequel to The Hobbit, it addressed an older audience, drawing on the immense backstory of Beleriand that Tolkien had constructed in previous years, which eventually saw posthumous publication in The Silmarillion and other volumes. Tolkien strongly influenced the fantasy genre that grew up after the book's success. The Lord of the Rings became immensely popular in the 1960s and has remained so ever since, ranking as one of the most popular works of fiction of the 20th century, judged by both sales and reader surveys. In the 2003 "Big Read" survey conducted by the BBC, The Lord of the Rings was found to be the UK's "Best-loved Novel".
Sources: en.wikipedia.org
== Protein-derived cofactors == In a number of enzymes, the moiety that acts as a cofactor is formed by post-translational modification of a part of the protein sequence. This often replaces the need for an external binding factor, such as a metal ion, for protein function. Potential modifications could be oxidation of aromatic residues, binding between residues, cleavage or ring-forming. These alterations are distinct from other post-translation protein modifications, such as phosphorylation, methylation, or glycosylation in that the amino acids typically acquire new functions. This increases the functionality of the protein; unmodified amino acids are typically limited to acid-base reactions, and the alteration of resides can give the protein electrophilic sites or the ability to stabilize free radicals. Examples of cofactor production include tryptophan tryptophylquinone (TTQ), derived from two tryptophan side chains, and 4-methylidene-imidazole-5-one (MIO), derived from an Ala-Ser-Gly motif. Characterization of protein-derived cofactors is conducted using X-ray crystallography and mass spectroscopy; structural data is necessary because sequencing does not readily identify the altered sites.
== Heterogeneous ribosomes == In 1958, Francis Crick famously proposed the "one gene-one ribosome-one protein hypothesis," where each ribosome carries the genetic information required to encode a single protein. Although discredited at that time, from the discovery of the first ribosomopathy Diamond–Blackfan Anemia in 1999, the ribosome has transitioned from a passive molecular machine to a dynamic macromolecular machine.Ribosomes are compositionally heterogeneous between species and even within the same cell, as evidenced by the existence of cytoplasmic and mitochondria ribosomes within the same eukaryotic cells. Certain researchers have suggested that heterogeneity in the composition of ribosomal proteins in mammals is important for gene regulation, i.e., the specialized ribosome hypothesis. However, this hypothesis is controversial and the topic of ongoing research. Heterogeneity in ribosome composition was first proposed to be involved in translational control of protein synthesis by Vince Mauro and Gerald Edelman. They proposed the ribosome filter hypothesis to explain the regulatory functions of ribosomes. Evidence has suggested that specialized ribosomes specific to different cell populations may affect how genes are translated. Some ribosomal proteins exchange from the assembled complex with cytosolic copies suggesting that the structure of the in vivo ribosome can be modified without synthesizing an entire new ribosome. Certain ribosomal proteins are absolutely critical for cellular life while others are not.
Han Chinese who committed crimes such as those dealing with opium became slaves to the begs, this practice was administered by Qing law. Most Chinese in Altishahr were exile slaves to Turkestani Begs. While free Chinese merchants generally did not engage in relationships with East Turkestani women, some of the Chinese slaves belonging to begs, along with Green Standard soldiers, Bannermen, and Manchus, engaged in affairs with the East Turkestani women that were serious in nature.
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.
It binds to and activates PPAR delta, a nuclear receptor that controls expression of genes related to fatty acid oxidation. This mechanism can alter energy metabolism in animal models. It is not a direct stimulant or fat-burning enzyme.