unapproved substance 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 2025-08-04 and is reviewed periodically as new material appears.
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.
Legal status varies by country. In some places, cardarine is controlled under medicines or psychoactive substances laws; in others, it may be sold with minimal oversight as a research chemical. Customs agencies have intercepted shipments, and several national health agencies have issued warnings about products marketed for bodybuilding or performance enhancement. The lack of a standardized pharmaceutical supply means identity, purity, and contamination levels can differ widely between samples. These factors make cardarine a regulatory and public health concern rather than a conventional prescription drug.
Cardarine is a common name for GW501516, a synthetic compound first described in the 1990s as a selective agonist of the peroxisome proliferator-activated receptor delta. It was studied in preclinical models for metabolic and cardiovascular conditions, but it has not been approved as a medicine in the United States, Europe, or other major jurisdictions. Retail products labeled as cardarine are generally research chemicals or supplements, not pharmaceutical formulations. Because human safety and efficacy data remain limited, regulatory agencies treat it as an unapproved substance rather than a therapeutic product.
| Property | Value | Notes |
|---|---|---|
| Common name | Cardarine | Common internet and media name. |
| Research code | GW501516 | Also written GW-1516. |
| Drug class | PPARδ agonist | Not a selective androgen receptor modulator. |
| Development status | Discontinued | Clinical development halted after rodent cancer findings. |
| Regulatory status | Prohibited in sport | Listed by WADA; not approved as medicine. |
=== United States === Radiology is a field in medicine that has expanded rapidly after 2000 due to advances in computer technology, which is closely linked to modern imaging techniques. Applying for residency positions in radiology has become highly competitive. Applicants are often near the top of their medical school classes, with high USMLE (board) examination scores. Diagnostic radiologists must complete prerequisite undergraduate education, four years of medical school to earn a medical degree (D.O. or M.D.), one year of internship, and four years of residency training. After residency, most radiologists pursue one or two years of additional specialty fellowship training. The American Board of Radiology (ABR) administers professional certification in Diagnostic Radiology, Radiation Oncology, and Medical Physics as well as subspecialty certification in neuroradiology, nuclear radiology, pediatric radiology, and vascular and interventional radiology. "Board Certification" in diagnostic radiology requires successful completion of two examinations. The Core Exam is given after 36 months of residency. Although previously taken in Chicago or Tucson, Arizona, beginning in February 2021, the computer test transitioned permanently to a remote format. It encompasses 18 categories. A passing score is 350 or above. A fail on one to five categories was previously a Conditioned exam; beginning in June 2021, the conditioned category will no longer exist, and the test will be graded as a whole. The Certification Exam can be taken 15 months after completion of the Radiology residency.
== Business development == In 2002, BioMarin acquired Glyko Biomedical. In 2009, BioMarin acquired Huxley Pharmaceuticals, Inc. (Huxley), which had rights to a proprietary form of 3,4-diaminopyridine (3,4-DAP), amifampridine phosphate. In 2010, BioMarin was granted marketing approval by the European Commission for 3,4-diaminopyridine (3,4-DAP), amifampridine phosphate for the treatment of the rare autoimmune disease Lambert–Eaton myasthenic syndrome (LEMS). BioMarin launched the product under the name Firdapse. In 2010, BioMarin acquired LEAD Therapeutics, Inc. (LEAD), a small private drug discovery and early stage development company with key compound LT-673, an orally available poly (ADP-ribose) polymerase (PARP) inhibitor studied for the treatment of patients with rare, genetically defined cancers. This acquisition was followed by the purchase of ZyStor Therapeutics, Inc. (ZyStor), a privately held biotechnology company developing ERTs for the treatment of lysosomal storage disorders and its lead product candidate, ZC-701, a fusion of insulin-like growth factor 2 and alpha glucosidase (IGF2-GAA) in development for Pompe disease. At its R&D day in October 2010, BioMarin also announced a new program for a peptide therapeutic, vosoritide (BMN-111), for the treatment of achondroplasia. In 2012, BioMarin acquired Zacharon Pharmaceuticals, a private biotechnology company based in San Diego focused on developing small molecules targeting pathways of glycan metabolism.
=== Purification === The biotin tag can be used in affinity chromatography together with a column that has avidin (or streptavidin or neutravidin) bound to it, which is the natural ligand for biotin. However, harsh conditions (e.g., 6M GuHCl at pH 1.5) are needed to break the avidin/streptavidin - biotin interaction, which will most likely denature the protein carrying the biotin tag. If isolation of the tagged protein is needed, it is better to tag the protein with iminobiotin. This biotin analogue gives strong binding to avidin/streptavidin at alkaline pH, but the affinity is reduced upon lowering the pH. Therefore, an iminobiotin-tagged functional protein can be released from an avidin/streptavidin column by decreasing the pH (to around pH 4).
== Functions == Anabolic processes build organs and tissues. These processes produce growth and differentiation of cells and increase in body size, a process that involves synthesis of complex molecules. Examples of anabolic processes include the growth and mineralization of bone and increases in muscle mass.
=== Roberts relieves the sieges === Roberts launched his main attack on 10 February 1900 and although hampered by a long supply route, managed to outflank the Boers defending Magersfontein. On 14 February, a cavalry division under French launched a major attack to relieve Kimberley. Although encountering severe fire, a massed cavalry charge split the Boer defences on 15 February, opening the way for French to enter Kimberley that evening, ending its 124 days' siege. Meanwhile, Roberts pursued Piet Cronjé's 7,000-strong force, which had abandoned Magersfontein to head for Bloemfontein. French's cavalry was ordered to assist in the pursuit by embarking on an epic 50 km (31 mi) drive towards Paardeberg where Cronjé was attempting to cross the Modder River. At the Battle of Paardeberg from 18 to 27 February, Roberts then surrounded Cronjé's retreating Boer army. On 17 February, a pincer movement involving French's cavalry and the main British force attempted to take the entrenched position, but the frontal attacks were uncoordinated and so repulsed by the Boers. Finally, Roberts resorted to bombarding Cronjé into submission. It took ten days, and when the British troops used the polluted Modder River as water supply, typhoid killed many troops. General Cronjé was finally forced to surrender at the Battle of Paardeberg with 4,000 men.
Sources: en.wikipedia.org
==== Metabolism ==== Ramelteon is metabolized in the liver primarily by oxidation via hydroxylation and carbonylation. It is also secondarily metabolized to produce glucuronide conjugates. Ramelteon is metabolized mainly by CYP1A2 while CYP2C enzymes and CYP3A4 are involved to a minor extent. The metabolites of ramelteon include M-I, M-II, M-III, and M-IV. Exposure to M-II is approximately 20- to 100-fold higher than to ramelteon.
The digital ion trap (DIT) is an quadrupole ion trap driven by digital signals, typically in a rectangular waveform, generated by switching rapidly between discrete DC voltage levels. The digital ion trap has been mainly developed as a mass analyzer.
=== Leak === On September 19, the Half-Life 2 source code was obtained by a German hacker, Axel Gembe, who had infiltrated Valve's internal network months earlier. According to Gembe, he shared it with another person, who leaked the code online in early October. Fans soon compiled a playable version of Half-Life 2, revealing how unfinished it was. The leaks damaged morale at Valve and slowed development. Fans also provided Valve with the details of people involved in the leaks. In March 2004, Gembe contacted Newell, saying he was a fan and had not acted maliciously. Newell worked with the FBI to invite Gembe to a fake job interview, planning to have him arrested in the United States; however, police arrested him in Germany. In November 2006, Gembe was sentenced to two years' probation. Valve implemented new policies to protect against leaks, such as requiring journalists to attend their office to play it before release.
Valproate is a weak or low-potency histone deacetylase inhibitor, specifically of the class I HDAC1, HDAC2, HDAC3, and HDAC8, but not of other HDACs. Earlier studies found a wide range of inhibitory potencies of valproate against HDACs, ranging from low micromolar to millimolar concentrations, but subsequent work with improved methodology has supported greater inhibitory potencies, with IC50Tooltip half-maximal inhibitory concentration values in the range of 36 to 219 μM for the class I HDACs. For comparison, valproate was found to be 4- to 46-fold less potent in inhibiting the class I HDACs relative to butyric acid (butyrate). By inhibiting HDACs, valproate promotes more transcriptionally active chromatin structures, that is it exerts an epigenetic effect. This has been proven in mice: Valproic acid induced histone hyperacetylation had brain function effects on the next generation of mice through changes in sperm DNA methylation. Intermediate molecules include VEGF, BDNF, and GDNF.
Sources: en.wikipedia.org
Within a month of the outbreak of the Korean War, 10 F-51D Mustangs were provided to the badly depleted Republic of Korea Air Force as a part of the Bout One Project. They were flown by both South Korean airmen, several of whom were veterans of the Imperial Japanese Army and Navy air services during World War II, as well as by US advisers led by Major Dean Hess. Later, more were provided both from US and from South African stocks, as the latter were converting to F-86 Sabres. They formed the backbone of the South Korean Air Force until they were replaced by Sabres. It also served with the ROKAF Black Eagles aerobatic team, until retired in 1954. Sweden
The four substrates of this enzyme are precorrin-3A, reduced nicotinamide adenine dinucleotide (NADH), oxygen, and a proton. Its products are precorrin-3B, oxidised NAD+, and water. This enzyme is an iron–sulfur protein acting as an oxidoreductase, with molecular oxygen as oxidant and incorporating one of its atoms. The systematic name of this enzyme class is precorrin-3A,NADH:oxygen oxidoreductase (20-hydroxylating). Other names in common use include precorrin-3X synthase, and CobG. This enzyme is part of the biosynthetic pathway to cobalamin (vitamin B12) in aerobic bacteria.
=== Purity determination (w/w NMR) === While NMR is primarily used for structural determination, it can also be used for purity determination, provided that the structure and molecular weight of the compound is known. This technique requires the use of an internal standard of known purity. Typically this standard will have a high molecular weight to facilitate accurate weighing, but relatively few protons so as to give a clear peak for later integration e.g. 1,2,4,5-tetrachloro-3-nitrobenzene. Accurately weighed portions of the standard and sample are combined and analysed by NMR. Suitable peaks from both compounds are selected and the purity of the sample is determined via the following equation.
Sources: en.wikipedia.org
No. Cardarine is a PPARδ agonist, while selective androgen receptor modulators act on androgen receptors. The two classes differ in receptor target and downstream effects.
Preclinical rodent studies reported cancers, including liver and bladder tumors, at tested doses. The human relevance of those findings is uncertain, but development was discontinued. No approved human product resulted.
No. It remains an investigational compound without approved therapeutic labeling. Sports regulators prohibit its use, and health agencies have warned against consuming it.
No. Major drug regulators have not approved GW501516 for treating any medical condition. Products sold as cardarine are typically unapproved research chemicals or supplements, so their contents and safety are not assured.