Prohibited list 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 2025-12-22 and is reviewed periodically as new material appears.
Human trials of GW501516 were small and short in duration. They examined lipid levels, glucose handling, and other metabolic markers, but the programs were halted after the animal cancer findings. No approved therapeutic product exists, and published human data are insufficient for establishing long-term safety. Reports of use for athletic performance come mainly from non-clinical settings and cannot be verified through controlled trials. Independent testing of products sold as cardarine has found inconsistent purity and labeling.
Laboratory studies indicate that GW501516 activates PPARδ, a nuclear receptor involved in fatty acid oxidation and energy metabolism. In rodent experiments, treated animals often showed increased endurance and reduced fat mass. These effects were observed under controlled conditions and do not establish safe or effective use in humans. The exact dose-response relationship in humans remains poorly characterized. Species differences in metabolism can affect how results translate across animals and people.
Safety concerns emerged from long-term animal studies. In rodents given the compound for extended periods, researchers found an increased incidence of certain cancers, including liver and bladder tumors. These findings contributed to the discontinuation of clinical development. Whether similar risks apply to short-term or low-level exposure in humans is not established, and controlled human safety data are limited. The relevance of high-dose rodent carcinogenicity findings to human use remains a subject of debate.
Published literature on cardarine includes in vitro assays, rodent experiments, and a small number of human studies. Reports describe effects on exercise capacity and lipid metabolism in animals, while human evidence is sparse. Many online descriptions present the compound as a proven endurance aid, a claim not supported by regulatory approval or large clinical trials. Analytical studies focus on identifying the parent compound and its metabolites in biological samples. Important uncertainties include species differences, dose-response relationships, and the relevance of rodent tumor findings to humans.
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.
| Property | Value | Notes |
|---|---|---|
| Primary target | PPARδ (NR1C2) | Nuclear receptor involved in lipid metabolism |
| Preclinical effect | Increased fatty acid oxidation | Observed in rodent studies |
| Key safety signal | Tumors in rodents after long-term exposure | Contributed to halted clinical development |
| Human trial status | No approved product; development stopped | Limited short-term metabolic data |
| Sport regulatory status | Prohibited at all times | WADA hormone and metabolic modulators class |
A persistent misconception is that cardarine is a fat-burning drug or a safe alternative to anabolic steroids. No approved therapeutic product exists, and human safety data are limited. The tumor findings in rodents remain a central concern in scientific reviews. Products sold online may contain inaccurate labels, impurities, or different compounds entirely, which complicates any assessment of effects. Independent testing of such products has reported frequent mislabeling. For these reasons, discussions in the literature emphasize risks and unknowns rather than benefits.
Cardarine is not approved for human therapeutic use in any major jurisdiction. It appears on the World Anti-Doping Agency Prohibited List as a PPARδ agonist within the hormone and metabolic modulators category. Sports organizations test for it because it has been detected in athlete samples and seized products. Regulatory actions against marketed research chemical versions have occurred in several countries, though enforcement varies. Availability through unregulated channels complicates oversight.
Analytical laboratories typically identify cardarine and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is a common matrix in anti-doping testing, while blood and tissue may be used in research settings. Detection windows depend on the assay, the sample matrix, and the compound's metabolism. Because cardarine is extensively metabolized, laboratories often target specific metabolites to improve sensitivity and confirmation. Reference standards are required for reliable quantification. Method validation includes checks for selectivity, linearity, and carryover.
A common misconception is that cardarine has been proven safe for human use. In reality, human clinical data are limited, and long-term animal studies have raised concerns about cancer. Another misconception is that it is a supplement or vitamin-like compound. It is a synthetic research chemical with no approved medical indication. Scientific discussion often focuses on its mechanism and detection rather than therapeutic use. Regulatory and anti-doping literature treats it primarily as a prohibited substance.
Cardarine is explicitly prohibited by the World Anti-Doping Agency under the class of PPARδ agonists. Its presence in urine or blood samples can be detected using mass spectrometry-based methods, often liquid chromatography-tandem mass spectrometry. Athletes who test positive may face sanctions, including bans from competition. The compound is also regulated as a prescription-only or unapproved drug in many countries. Enforcement varies by jurisdiction, and some regions treat it as a controlled substance. Online sales may occur despite these restrictions, creating quality and legal risks.
Laboratory detection of cardarine typically involves sample preparation followed by chromatographic separation and mass spectrometric identification. Urine is the most common matrix for anti-doping tests, though blood and hair have also been explored. Methods can target the parent compound or its metabolites, depending on the expected window of detection. Reference standards are required for accurate quantification. Matrix effects and dilution can influence results, so laboratories use internal standards and validation protocols. The exact detection window varies with dose, route, and individual metabolism.
Polyubiquitylation is the formation of a ubiquitin chain on a single lysine residue on the substrate protein. Following addition of a single ubiquitin moiety to a protein substrate, further ubiquitin molecules can be added to the first, yielding a polyubiquitin chain. These chains are made by linking the glycine residue of a ubiquitin molecule to a lysine of ubiquitin bound to a substrate. Ubiquitin has seven lysine residues and an N-terminus that serves as points of ubiquitination; they are K6, K11, K27, K29, K33, K48, K63 and M1, respectively. Lysine 48-linked chains were the first identified and are the best-characterised type of ubiquitin chain. K63 chains have also been well-characterised, whereas the function of other lysine chains, mixed chains, branched chains, M1-linked linear chains, and heterologous chains (mixtures of ubiquitin and other ubiquitin-like proteins) remains more unclear. Lysine 48-linked polyubiquitin chains target proteins for destruction, by a process known as proteolysis. Multi-ubiquitin chains at least four ubiquitin molecules long must be attached to a lysine residue on the condemned protein in order for it to be recognised by the 26S proteasome. This is a barrel-shape structure comprising a central proteolytic core made of four ring structures, flanked by two cylinders that selectively allow entry of ubiquitylated proteins. Once inside, the proteins are rapidly degraded into small peptides (usually 3–25 amino acid residues in length).
The Slave Trade Act was passed by the British Parliament on March 25, 1807, making the slave trade illegal throughout the British Empire, Wilberforce also campaigned for abolition of slavery in the British Empire, which he lived to see in the Slavery Abolition Act 1833. After the 1807 act abolishing the slave trade was passed, these campaigners switched to encouraging other countries to follow suit, notably France and the British colonies. Between 1808 and 1860, the British West Africa Squadron seized approximately 1,600 slave ships and freed 150,000 Africans who were aboard. Action was also taken against African leaders who refused to agree to British treaties to outlaw the trade, for example against "the usurping King of Lagos", deposed in 1851. Anti-slavery treaties were signed with over 50 African rulers.
=== Osteoconduction === Osteoconduction is termed as "the property of a material to support tissue ingrowth, osteoprogenitor cell growth, and development for bone formation to occur". In the context of bone grafting it occurs when the bone graft material serves as a scaffold for new bone growth that is perpetuated by the native bone. Osteoblasts from the margin of the defect that is being grafted utilize the bone graft material as a framework upon which to spread and generate new bone. Osteoblasts do not originate from the donor tissue, but through the internal ingrowing of the host's cells. The proper bonding of bioactive chemicals (Beta-Tricalcium Phosphate) in implants used in bone grafting surgery allow the promotion of osteoconductivity in the area of a defect. In the very least, a bone graft material should be osteoconductive by being made up of these bioactive chemicals.
== Life and career == Li was born in Guangzhou and educated at the Nanjing University. In 1935, he immigrated to the US, where he took up postgraduate studies at the University of California, Berkeley, and later joined the staff. He became professor in 1950. He served as Director of the Hormone Research Laboratory at Berkeley from 1950 to 1967 and at UCSF from 1967 until his retirement in 1983. In 1955, he was elected as Academician of Academia Sinica, Republic of China. Li dedicated his entire academic career studying the pituitary-gland hormones. In collaboration with various co-workers, he isolated several protein hormones, including adrenocorticotropic hormone (ACTH), which stimulates the adrenal cortex to increase its secretion of corticoids. In 1956, Li and his group showed that ACTH consists of 39 amino acids arranged in a specific order, and that the whole chain of the natural hormone is not necessary for its action. He isolated another pituitary hormone called melanocyte-stimulating hormone (MSH) and found that not only does this hormone produce some effects similar to those produced by ACTH, but also that part of the amino acid chain of MSH is the same as that of ACTH.
Serine–tRNA ligase, cytoplasmic, also called seryl-tRNA synthetase 1 is an enzyme that in humans is encoded by the gene SARS1 (previously SARS). SARS belongs to the class II amino-acyl tRNA family and is found in all humans, and functions as a serine–tRNA ligase which is involved in protein translation and is related to several bacterial and yeast counterparts.
Sources: en.wikipedia.org
=== 2025: Australian Open final, 500th win === Alongside Team Germany, Zverev failed to defend the United Cup after withdrawing from the event due to injury. Entering the 2025 Australian Open as the second seed for the first time in his career, Zverev began his tournament with a dominant victory over 2019 semifinalist Lucas Pouille in the first round. He reached his second consecutive and third overall semifinal at the Australian Open defeating Pedro Martínez, Jacob Fearnley, Ugo Humbert, and Tommy Paul. Against the 24-time major champion, Zverev won the 81-minute first set against Djokovic before the latter's retirement due to injury, advancing to his third major final. In the final, Zverev lost to defending champion Jannik Sinner in straight sets. Following his defeat to Sinner, a visibly distraught Zverev delivered an emotional speech during the trophy ceremony, stating, "I want to thank my team... I'm just not good enough. It's as simple as that." In the post-match press conference, he reflected on his career trajectory and the pressure of being a perennial contender without a Major title, reportedly remarking that he "didn't want to be the best player in history without a Grand Slam", expressing his desperation to finally break the barrier after losing his third major final. Over the next two months, Zverev made quarterfinals at the South American events he played in, Buenos Aires and Rio de Janeiro, losing to Argentines Francisco Cerundolo and Francisco Comesana, respectively.
Liakhov, a vigorous, able, and reactionary officer firmly committed to upholding absolute monarchies whatever in Russia or Iran, transformed the Persian Cossack Brigade into a mounted para-military police force rather than as a combat force. Liakhov was close to the new Shah, Mohammed Ali, who ascended to the Peacock Throne in January 1907, and it was due to the shah's patronage that Liakhov transformed the Persian Cossack Brigade into the main bulwark of the Iranian state. In June 1908, Liakhov led the Cossack Brigade in bombarding the Majlis (Parliament) while being appointed military governor of Tehran as the shah attempted to do away with the constitution his father had been forced to grant in 1906 Reza Khan, who became the first Iranian to command the Cossack Brigade led the coup d'état in 1921 and in 1925 deposed the Qajars to found a new dynasty. After the outbreak of World War I in August 1914, Cossacks became a key component in the cavalry of the Imperial Russian Army. The mounted Cossacks made up 38 regiments, plus some infantry battalions and 52 horse artillery batteries. Initially, each Russian cavalry division included a regiment of Cossacks in addition to regular units of hussars, lancers, and dragoons. By 1916, the Cossacks' wartime strength had expanded to 160 regiments, plus 176 independent sotnias (squadrons) employed as detached units. The importance of cavalry in the frontlines faded after the opening phase of the war settled into a stalemate.
=== Deficiency === Low plasma magnesium (hypomagnesemia) is common: it is found in 2.5–15% of the general population. From 2005 to 2006, 48 percent of the United States population consumed less magnesium than recommended in the Dietary Reference Intake. Other causes are increased renal or gastrointestinal loss, an increased intracellular shift, and proton-pump inhibitor antacid therapy. Most are asymptomatic, but symptoms referable to neuromuscular, cardiovascular, and metabolic dysfunction may occur. Alcoholism is often associated with magnesium deficiency. Chronically low serum magnesium levels are associated with metabolic syndrome, diabetes mellitus type 2, fasciculation, and hypertension.
Flare-ups of autoimmune conditions such as systemic lupus erythematosus and rheumatoid arthritis may also occur during this period. Patients on tumor necrosis factor antagonists Patients with chronic inflammatory conditions (Crohn's disease, ulcerative colitis, sarcoidosis, etc.) are often treated with TNF antagonists, such as infliximab, adalimumab, and etanercept. Tumor necrosis factors are critical in macrophage activation and subsequent granuloma formation. Therefore, TNF antagonists impair the host immune response against infections such as tuberculosis. While the patient is taking TNF antagonists, these infections may remain latent and asymptomatic. However, when these medications are discontinued, there may be an associated pro-inflammatory response causing the infection to be uncovered.
== The Protein == The 25-kDa core protein (excluding the heavy glycosylation) of rodent Thy-1 is 111 or 112 amino acids in length, and is N-glycosylated at three sites (In contrast to only two glycosylation sites for human Thy-1). The 162aa (murine, 161 for human) Thy1 precursor has 19 amino acid (aa 1–19) signal sequence and 31 amino acid (aa 132–162) C-terminal transmembrane domain that is present in pro form but removed when transferring the 112 amino acid (aa 20–131) mature peptide to GPI anchor which would attach through the aa 131. Some of the common monoclonal antibodies used to detect this protein are clones OX7, 5E10, K117 and L127. There have been some reports of Thy1 monoclonal antibodies cross reacting with some cytoskeletal elements: anti Thy-1.2 with actin in marsupial, murine, and human cells and anti Thy-1.1 with vimentin, and were suggested to be due to sequence homology by studies done more than 20 years back. Thy-1, like many other GPI anchored proteins can be shed by special types of Phospholipase C e.g. PI-PLC (phosphatidyl-Inositol Phospholipase C, or PLC β). it can also be involved in cell to cell transfer of GPI anchored proteins like CD55 and CD59.
Sources: en.wikipedia.org
=== Pharmacokinetics === Metandienone has high oral bioavailability. It has very low affinity for human serum sex hormone-binding globulin (SHBG), about 10% of that of testosterone and 2% of that of DHT. The drug is metabolized in the liver by 6β-hydroxylation, 3α- and 3β-oxidation, 5β-reduction, 17-epimerization, and conjugation among other reactions. Unlike methyltestosterone, owing to the presence of its C1(2) double bond, metandienone does not produce 5α-reduced metabolites. The elimination half-life of metandienone is about 3 to 6 hours. It is eliminated in the urine.
AMP + diphosphate + NAD+ The 3 substrates of this enzyme are ATP, deamido-NAD+, and NH3, whereas its 3 products are AMP, diphosphate, and NAD+. This enzyme belongs to the family of ligases, specifically those forming carbon-nitrogen bonds as acid-D-ammonia (or amine) ligases (amide synthetase). The systematic name of this enzyme class is deamido-NAD+:ammonia ligase (AMP-forming). Other names in common use include NAD+ synthetase, NAD+ synthetase, nicotinamide adenine dinucleotide synthetase, and diphosphopyridine nucleotide synthetase. This enzyme participates in nicotinate and nicotinamide metabolism and nitrogen metabolism.
== External links == N-Terminal Fusion of Target Protein to Maltose-Binding Protein at Michigan Technological University maltose-binding+protein at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Generic protocol for the expression and purification of recombinant proteins in Escherichia coli using a combinatorial His6-maltose binding protein fusion tag
=== Ansa-bridging macrolactone === The ansa-bridging macrolactone was constructed following the first Sonogashira coupling, using the Shiina macrolactonization. This protocol was performed on the gram-scale without diminishing its yield employing 2-methyl-6-nitrobenzoic anhydride, 4-dimethylaminopyridine, and triethylamine as a base to promote intramolecular esterification.
Hence by following the hydrogen ion concentration during a titration of a mixture of M and HL with base, and knowing the acid dissociation constant of HL, the stability constant for the formation of ML could be determined. Bjerrum went on to determine the stability constants for systems in which many complexes may be formed.
Sources: en.wikipedia.org
Rodent studies reported increased endurance and fat oxidation after GW501516 exposure. Long-term studies also found higher rates of some tumors, which led to halted development.
Small short-term human trials examined metabolic markers such as lipids and glucose. The trials did not continue after rodent cancer findings, so long-term human safety is unknown.
Controlled human trials have not established a performance benefit. Anecdotal reports exist, but they are not reliable evidence.
Cardarine is a common name for the investigational compound GW501516. It acts as a PPARδ agonist and is not approved for human use. It is prohibited in sport.