The short version of LC-MS/MS fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-03-29. Anything still debated is marked as such rather than presented as settled.
Sporting authorities added GW501516 to prohibited lists after it appeared in athlete samples and online markets. The World Anti-Doping Agency classifies it as a hormone and metabolic modulator, and its use can lead to an anti-doping rule violation. Some early laboratory work suggested effects on fatty acid oxidation and endurance-related metabolism in animals, but those findings do not establish safe or effective use in people. Reports of adverse events in humans are scarce and often anecdotal, which complicates risk assessment.
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.
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.
| Property | Value | Notes |
|---|---|---|
| IUPAC name | {4-[({4-methyl-2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-5-yl}methyl)sulfanyl]phenoxy}acetic acid | Systematic name for GW501516 |
| CAS Registry Number | 317318-70-0 | Unique identifier for the parent compound |
| Molecular formula | C21H18F3NO3S2 | Includes carbon, hydrogen, fluorine, nitrogen, oxygen, and sulfur |
| Molecular weight | 453.5 g/mol | Approximate value for the neutral form |
| Appearance | White to off-white powder | Typical description for purified laboratory material |
Cardarine has no approved therapeutic indication and is not marketed as a medicine. The World Anti-Doping Agency lists GW501516 as a prohibited substance at all times, covering both in-competition and out-of-competition periods. National laws vary: some countries treat it as an unapproved drug subject to import controls, while others have specific restrictions on sale for human consumption. It is often sold as a research chemical, a label that does not imply safety or legality. Enforcement actions have targeted online vendors and shipments.
Anti-doping laboratories identify GW501516 and related metabolites using liquid chromatography coupled with tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be analyzed. The method targets the parent compound and phase I and phase II metabolites, which extend the detection window. Because the substance is prohibited at all times, athletes can be tested outside competition. Detection limits and windows depend on the assay, sample type, and individual metabolism.
Cardarine is frequently described as a fat-burning or endurance-enhancing supplement, but these claims exceed the available evidence. The compound is not a hormone, steroid, or selective androgen receptor modulator. Research articles discuss it as a tool compound for studying PPARδ biology, while anti-doping literature focuses on its abuse and detection. Quality of unapproved products is uncertain, and independent analyses have found impurities or incorrect labeling. Open questions include whether human cancer risk resembles that seen in rodents and how often non-athletes use the substance.
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.
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.
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 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.
In the context of these functional rearrangements, these tertiary or quaternary structures are usually referred to as "conformations", and transitions between them are called conformational changes. Such changes are often induced by the binding of a substrate molecule to an enzyme's active site, or the physical region of the protein that participates in chemical catalysis. In solution, protein structures vary because of thermal vibration and collisions with other molecules.
Pivampicillin (pivaloyloxymethyl ester of ampicillin) Bacampicillin Metampicillin (formaldehyde ester of ampicillin) Talampicillin Hetacillin (ampicillin conjugated to acetone) Epicillin is an aminopenicillin that has never seen widespread clinical use.
By the end of March 2021 RDIF anticipates 33 million doses will have been manufactured in Russia, less than 5% of which will have been exported. An agreement for the production of over 100 million doses of vaccine in India was made with Dr. Reddy's Laboratories, which on 11 January 2021 submitted mid-stage trial data to the Indian regulator and recommended moving onto late-stage trials. The RDIF announced plans to sell 100 million doses to India, 35 million to Uzbekistan, and 32 million to Mexico, as well as 25 million each to Nepal and Egypt. In India, the first dose of Sputnik V vaccine was administered on 14 May 2021 at Hyderabad. Argentina became the first Latin American country to produce it. Large-scale production started in June 2021. As of 31 December 2021 277 million doses were manufactured, mostly (265 million) in Russia. On 28 February 2022, as a result of the 2022 Russian invasion of Ukraine, the United States placed RDIF and its chief executive on its list of sanctioned Russian entities and people. The European Union, Ukraine, United Kingdom and Australia followed later in February and in March. This significantly reduces vaccine's future commercial prospects.
Sources: en.wikipedia.org
Reynolds was powerless to prevent the inevitable; although leading at half-time, Geelong kicked five goals to Essendon's two points in the third quarter to set up victory by 11 points. Essendon slumped to 8th in 1952, but Coleman was in strong form, managing 103 goals for the year. Two seasons later, Coleman's career was ended after he dislocated a knee during the Round 8 clash with the North Melbourne Football Club at Essendon. Aged just 25, he had kicked 537 goals in only 98 VFL games. Following Coleman's career-ending knee injury, Essendon won no further premierships in the 1950s. In 1957, Essendon defeated Melbourne by 16 points in the Second Semi-Final, but lost the grand final to Melbourne by 61 points. The 1959 season ended with a 37-point grand final loss to Melbourne. Essendon would win their next premiership three years later in 1962.
== Bibliography (selection) == Langer, Ellen J. (1989). Mindfulness. Reading, MA: Addison Wesley. ISBN 978-0-201-52341-6. Langer, Ellen J. (1997). The Power of Mindful Learning. Reading, MA: Addison-Wesley. ISBN 978-0-201-33991-8. Langer, Ellen J. (2005). On Becoming an Artist. New York: Ballantine Books. ISBN 978-0-345-45629-8. Langer, Ellen J. (2009). Counter clockwise: mindful health and the power of possibility. New York: Ballantine Books. ISBN 978-0-345-50204-9. Langer, Ellen J. (2023). The Mindful Body: Thinking Our Way to Chronic Health. New York: Ballantine Books. ISBN 978-0-593-49794-4.
==== Transport proteins and membrane translocons ==== After a chloroplast polypeptide is synthesized on a ribosome in the cytosol, an enzyme specific to chloroplast proteins phosphorylates, or adds a phosphate group to many (but not all) of them in their transit sequences. Phosphorylation helps many proteins bind the polypeptide, keeping it from folding prematurely. This is important because it prevents chloroplast proteins from assuming their active form and carrying out their chloroplast functions in the wrong place—the cytosol. At the same time, they have to keep just enough shape so that they can be recognized by the chloroplast. These proteins also help the polypeptide get imported into the chloroplast. From here, chloroplast proteins bound for the stroma must pass through two protein complexes—the TOC complex, or translocon on the outer chloroplast membrane, and the TIC translocon, or translocon on the inner chloroplast membrane translocon. Chloroplast polypeptide chains probably often travel through the two complexes at the same time, but the TIC complex can also retrieve preproteins lost in the intermembrane space.
Sources: en.wikipedia.org
=== Pain Management === Intracerebroventricular injection has also been used for pain management. Several studies of refractory head and facial pain, peripheral nerve injury, and other persistent pain conditions have been completed. In one study, six patients with either refractory trigeminal neuralgia or cluster headaches were treated with an ICV opiate infusion pump. Visual analog scores (VAS) were obtained before and after injection to measure effectiveness. When compared, VAS scores improved from an average of 7.8 to 2.8 after the procedure. Most complications that occurred from this procedure consisted of nausea and drowsiness. These symptoms went away after the pump was adjusted. ICV pumps are typically kept in and replaced every four to five years, making the procedure ideal for patients with chronic pain. The CTK 01512-2 peptide toxin can act as a voltage-gated calcium channel (VGCC) blocker. In previous studies, it was shown to have a prolonged effect on preventing and reducing the processing of harmful stimuli by the central nervous system and peripheral nervous system. To strengthen this finding, the CTK 01512-2 toxin was tested on two models of persistent pain. These models include chronic post-ischemia pain (CPIP) and paclitaxel-induced peripheral neuropathy. Additionally, the peptide was injected using three routes of administration: intravenous, intrathecal, and intracerebroventricular. This approach is beneficial for patients who do not respond to traditional pain management approaches.
This influx of sodium ions, in the right conditions, can cause a depolarization event across the membrane. This opens calcium channels, causing intracellular calcium levels to increase. This increase in the concentration of calcium in the cytosol activates ryanodine receptors on the endoplasmic reticulum which causes the release of more calcium into the cytosol. This increase in calcium causes the secretion of somatostatin by the delta cells. Somatostatin inhibits glucagon secretion through the activation of SSTR2, a membrane bound protein that when activated causes a hyperpolarization of the membrane. This hyperpolarization causes voltage gated calcium channels to close, leading to a decrease in intracellular calcium levels. This causes a decrease in exocytosis. In the case of alpha cells, this causes a decrease in the secretion of glucagon. Serotonin inhibits the secretion of glucagon through its receptors on the plasma membrane of alpha cells. Alpha cells have 5-HT1f receptors which are triggered by the binding of serotonin. Once activated, these receptors suppress the action of adenylyl cyclase, which suppresses the production of cAMP. The inhibition of the production of cAMP in turn suppresses the secretion of glucagon. Serotonin is considered a paracrine signal due to the close proximity of beta cells to alpha cells. Glucose can also have a somewhat direct influence on glucagon secretion as well. This is through the influence of ATP. Cellular concentrations of ATP directly reflects the concentration of glucose in the blood.
The Portuguese Republican Party (Portuguese: Partido Republicano Português, pronounced [pɐɾˈtiðu ʁɛpuβliˈkɐnu puɾtuˈɣeʃ]) was a Portuguese political party formed during the late years of the constitutional monarchy that proposed and later brought about the replacement of the monarchy with the Portuguese First Republic. When the Republic was established on the 5 October 1910 Revolution, the members of the party initially stood together, but soon began splitting into different parties, including the Democratic Party, Republican Union, and Evolutionist Party, some of which themselves later merged or split to form the Democratic Leftwing Republican Party, Reformist Party, Centrist Republican Party, Popular Party, Radical Party, Republican Liberal Party, Liberal Republican Union, Reconstitution Party and Nationalist Republican Party.
Sources: en.wikipedia.org
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.
It is prohibited by the World Anti-Doping Agency as a hormone and metabolic modulator. Athletes who test positive for GW501516 can face sanctions, including suspensions and loss of results.
Cardarine is a common or trade-style name, while GW501516 is the research code for the same chemical entity. Some sources also use Endurobol or GSK-516. The names refer to the same compound, not distinct drugs.
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.