Certificate of analysis comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-07-16. Where a claim depends on a specific study, the study is described rather than over-claimed.
Early clinical research explored GW501516 for lipid disorders, obesity, and diabetes. Some short-term human studies reported changes in HDL cholesterol, LDL cholesterol, and triglycerides. The development program was discontinued after rodent studies showed dose-dependent tumor formation in multiple tissues, including liver, bladder, stomach, and skin. These findings raised concerns about long-term cancer risk in humans. Because human exposure data are limited, the clinical significance of the rodent tumors remains uncertain.
Literature on cardarine often separates receptor pharmacology from toxicology. Mechanistic papers describe PPARδ activation and gene expression changes, while safety assessments focus on carcinogenicity and species differences. Questions remain about whether rodent tumors arise through PPARδ-dependent or off-target mechanisms. Another open area is how human metabolism and exposure compare with those in animal studies. Analytical methods such as liquid chromatography–mass spectrometry are used to confirm identity in biological and product samples.
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.
GW501516 acts as a ligand for PPAR delta, a nuclear receptor that regulates transcription of genes involved in fatty acid oxidation and energy use. Activation of this receptor in skeletal muscle shifts metabolism toward fat burning in animal models. The compound does not burn fat directly; it changes gene expression over hours to days. Researchers study it to understand metabolic flexibility and exercise adaptation. Effects observed in rodents are not automatically expected in humans.
| Property | Value | Notes |
|---|---|---|
| Primary target | PPARδ | Nuclear receptor; not androgen receptor |
| Studied indications | Dyslipidemia; obesity; diabetes | Early clinical research; development discontinued |
| Rodent toxicity | Tumor formation in multiple tissues | Dose-dependent findings in some studies |
| Human approval | None | No approved therapeutic use |
| Typical analytical method | LC-MS/MS | Used for identity and quantification |
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.
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.
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.
Cardarine is the common name for GW501516, a synthetic compound studied as a peroxisome proliferator-activated receptor delta agonist. Researchers developed it to explore treatments for lipid disorders and metabolic conditions. It is not an approved medicine in any country. Early clinical work examined changes in HDL cholesterol and triglycerides, but development was discontinued after animal studies raised concerns about cancer. The compound remains available as a research chemical and appears in discussions of performance enhancement.
At the molecular level, GW501516 binds and activates PPARδ, a nuclear receptor that regulates transcription. Activation shifts expression of genes involved in fatty acid oxidation, energy expenditure, and lipid transport in skeletal muscle and liver. Animal studies report increased endurance and altered lipid profiles after exposure. Human data are limited to small trials and do not establish long-term safety or efficacy. PPARδ also has roles in cell proliferation, so the relationship between activation and cancer risk remains an open question.
In protein mass spectrometry, tandem mass spectrometry (also known as MS/MS or MS2) experiments are used for protein/peptide identification. Peptide identification algorithms fall into two broad classes: database search and de novo search. The former search takes place against a database containing all amino acid sequences assumed to be present in the analyzed sample. In contrast, the latter infers peptide sequences without knowledge of genomic data.
=== Pharmacodynamics === 1,2-Diarylethylamines primarily antagonize NMDA receptors, leading to dissociative effects like those of ketamine or phencyclidine (PCP). Many also interact with dopamine/norepinephrine transporters (DAT/NET) and sigma receptors, contributing to stimulant or hallucinogenic properties.
=== September === September 1 Texas implements the "Heartbeat Act" banning abortions after six weeks of pregnancy. Texas residents are allowed to carry handguns without a license or training. Aftermath of the January 6 United States Capitol attack: The Department of Justice secures its 50th guilty plea in its criminal investigation of the January 6 riot at the Capitol. A state of emergency is declared in New York City after record rainfall and flash flooding shuts down much of the city's transportation system, caused by Tropical Storm Ida. September 2 Hurricane Ida More than 54 deaths are reported in New York and the wider northeastern United States amid the ongoing flood emergency, as rescuers continue to search for stranded people. The Vine Street Expressway in Philadelphia is closed due to massive flooding on portions of the highway. The Park Towne Place residential complex is also evacuated due to flooding. September 3 Jake Angeli, the so-called "QAnon Shaman" pleads guilty to obstructing a proceeding of Congress during the January 6 attack. Texas Heartbeat Act: Texas state judge Guerra Gamble blocks the Texas Right To Life from suing Planned Parenthood under the pretext of the abortion law. September 8 – The Robert E. Lee Monument on Monument Avenue in Richmond, Virginia, a statue of Confederate General Robert E. Lee, is removed. September 9 COVID-19 vaccination in the United States: President Biden issues new federal vaccine requirements affecting up to 100 million Americans.
Inorganic chemistry deals with synthesis and behavior of inorganic and organometallic compounds. This field covers chemical compounds that are not carbon-based, which are the subjects of organic chemistry. The distinction between the two disciplines is far from absolute, as there is much overlap in the subdiscipline of organometallic chemistry. It has applications in every aspect of the chemical industry, including catalysis, materials science, pigments, surfactants, coatings, medications, fuels, and agriculture.
These kingdoms were defined as "the viceroyalties of New Spain (Mexico), Peru, New Granada, and Buenos Aires, and the independent captaincies general of the island of Cuba, Puerto Rico, Guatemala, Chile, Province of Venezuela, and the Philippines." This plan was criticized for providing unequal representation to Spanish America; nevertheless, throughout the end of 1808 and early 1809, the regional capitals elected candidates, whose names were forwarded to the capitals of the viceroyalties or captaincies general. Several important and large cities were left without direct representation in the Supreme Junta. In particular Quito and Chuquisaca, which saw themselves as the capitals of kingdoms, resented being subsumed in the larger Viceroyalty of Peru and Viceroyalty of the Río de la Plata respectively. This unrest led to the establishment of juntas in these cities in 1809, which were eventually quashed by the authorities within the year. An unsuccessful attempt at establishing a junta in New Spain was also stopped.
Sources: en.wikipedia.org
=== Roles in protein structure === In the translation of messenger RNA molecules to produce polypeptides, cysteine is coded for by the UGU and UGC codons. Cysteine has traditionally been considered to be a hydrophilic amino acid, based largely on the chemical parallel between its thiol group and the hydroxyl groups in the side chains of other polar amino acids. However, the cysteine side chain has been shown to stabilize hydrophobic interactions in micelles to a greater degree than the side chain in the nonpolar amino acid glycine and the polar amino acid serine. In a statistical analysis of the frequency with which amino acids appear in various proteins, cysteine residues were found to associate with hydrophobic regions of proteins. Their hydrophobic tendency was equivalent to that of known nonpolar amino acids such as methionine and tyrosine (tyrosine is polar aromatic but also hydrophobic), those of which were much greater than that of known polar amino acids such as serine and threonine. Hydrophobicity scales, which rank amino acids from most hydrophobic to most hydrophilic, consistently place cysteine towards the hydrophobic end of the spectrum, even when they are based on methods that are not influenced by the tendency of cysteines to form disulfide bonds in proteins. Therefore, cysteine is now often grouped among the hydrophobic amino acids, though it is sometimes also classified as slightly polar, or polar.
proved the intracellular uptake of cargo via endocytosis, along with cargo release as a result of coiled-coil dissociation. Dr. Ondřej Vaněk and colleagues utilized the same E3/K3-PHPMA system to attach an antibody to the polymer backbone to target the delivery of the drug system, which was successful in vitro. Coiled-coil polymer hybrid drug delivery systems can also be used in drug-free macromolecular therapeutic (DFMT) applications, whereby a coiled-coil-based system would be used to induce apoptosis in target cells. Specifically, Dr. Jindřich Kopeček and colleagues attempted to induce apoptosis in CD20-positive non-Hodgkin's lymphoma B-cells by mimicking the induction of apoptosis typically caused by the recognition of secondary antibodies to the CD20 antigen. In this case, apoptosis was induced upon the oligomerization of a PHMPA copolymer-conjugated coil to the anti-CD20 FAB fragment-conjugated coil (which would recognize and bind CD20). The coiled-coil motifs used in this system were the anti-parallel heterodimeric CCE/CCK coiled coils, which consist of pentaheptad repeats. This system was found to be successful at inducing apoptosis in those cells in vitro, providing an alternative to the anti-CD20 antibody drug Rituximab. Further studies have shown the efficacy of this system in vivo whereby malignant B-cells implanted in the bone marrow of mice were eradicated completely.
=== Computing, environmental, and interdisciplinary research === The National Science Foundation funded the iPlant Collaborative in 2008 with a $50 million grant. In 2013, iPlant Collaborative received a $50 million renewal grant. Rebranded in late 2015 as "CyVerse", the collaborative cloud-based data management platform is moving beyond life sciences to provide cloud-computing access across all scientific disciplines. In June 2011, the university announced it would assume full ownership of the Biosphere 2 scientific research facility in Oracle, Arizona. Biosphere 2 was constructed by private developers (funded mainly by Texas businessman and philanthropist Ed Bass) with its first closed system experiment commencing in 1991. The university had been the official management partner of the facility for research purposes since 2007.
Other azo dyes, which were previously used in textiles, printing, and plastic manufacturing, have been implicated as carcinogens that can cause bladder cancer. While phenazopyridine has never been shown to cause cancer in humans, evidence from animal models suggests that it is potentially carcinogenic.
== Experimental atomic gas phase chemistry == Interest in copernicium's chemistry was sparked by predictions that it would have the largest relativistic effects in the whole of period 7 and group 12, and indeed among all 118 known elements. Copernicium is expected to have the ground state electron configuration [Rn] 5f14 6d10 7s2 and thus should belong to group 12 of the periodic table, according to the Aufbau principle. As such, it should behave as the heavier homologue of mercury and form strong binary compounds with noble metals like gold. Experiments probing the reactivity of copernicium have focused on the adsorption of atoms of element 112 onto a gold surface held at varying temperatures, in order to calculate an adsorption enthalpy. Owing to relativistic stabilization of the 7s electrons, copernicium shows radon-like properties. Experiments were performed with the simultaneous formation of mercury and radon radioisotopes, allowing a comparison of adsorption characteristics. The first chemical experiments on copernicium were conducted using the 238U(48Ca,3n)283Cn reaction. Detection was by spontaneous fission of the claimed parent isotope with half-life of 5 minutes. Analysis of the data indicated that copernicium was more volatile than mercury and had noble gas properties. However, the confusion regarding the synthesis of copernicium-283 has cast some doubt on these experimental results.
Sources: en.wikipedia.org
In a 2013 interview, Forsythe lambasted the "[w]orst script ever written", adding, "basically, I don’t think there was one line from the script that we actually said in the movie." Hasty rewrites were made by Doninger, Cushnir and Harley Peyton based on collective feedback.
The earliest study of the nervous system dates to ancient Egypt. Trepanation, the surgical practice of either drilling or scraping a hole into the skull for the purpose of curing head injuries or mental disorders, or relieving cranial pressure, was first recorded during the Neolithic period. Manuscripts dating to 1700 BC indicate that the Egyptians had some knowledge about symptoms of brain damage. Early views on the function of the brain regarded it to be a "cranial stuffing" of sorts. In Egypt, from the late Middle Kingdom onwards, the brain was regularly removed in preparation for mummification. It was believed at the time that the heart was the seat of intelligence. According to Herodotus, the first step of mummification was to "take a crooked piece of iron, and with it draw out the brain through the nostrils, thus getting rid of a portion, while the skull is cleared of the rest by rinsing with drugs." Greek thinkers, beginning with Alcmaeon of Croton, advanced the cephalocentric hypothesis that the brain is the seat of sensation and thought. The view that the heart was the source of consciousness was not challenged until the time of the Greek physician Hippocrates. He believed that the brain was not only involved with sensation—since most specialized organs (e.g., eyes, ears, tongue) are located in the head near the brain—but was also the seat of intelligence. Plato also speculated that the brain was the seat of the rational part of the soul.
=== Film adaptation === A film adaptation has been in development hell since 2013, and it was reported on May 25, 2021, that the project is still in development by J.J. Abrams and Bad Robot and the script has been written. As of 2022, J.J. Abrams continued to express interest in bringing Portal to film. In 2026, Kane Parsons also expressed interest in directing a Portal film.
== External links == "Corticotropin-releasing Factor Receptors: CRF1". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Archived from the original on 2015-11-20. Retrieved 2008-12-04. Corticotropin-releasing+hormone+receptors at the U.S. National Library of Medicine Medical Subject Headings (MeSH) CRF+receptor+type+1 at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Overview of all the structural information available in the PDB for UniProt: P34998 (Corticotropin-releasing factor receptor 1) at the PDBe-KB.
Sources: en.wikipedia.org
It targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not act primarily on androgen receptors. This distinction separates it from SARMs.
Rodent studies found dose-dependent tumors in several organs. The sponsor discontinued the program over cancer concerns. Human risk from long-term use remains unknown.
Controlled human endurance trials are lacking. Animal studies show increased exercise capacity under some conditions. Anecdotal reports are not equivalent to clinical evidence.
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.