LC-MS/MS 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 2025-10-15. 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.
GW501516 binds and activates PPARδ, a nuclear receptor that influences transcription of genes involved in fatty acid oxidation and energy use. Activation shifts some metabolic pathways in preclinical models, which is why the compound has been studied for lipid disorders and exercise-related endpoints. The exact downstream effects in humans are incompletely mapped. PPARδ is expressed in many tissues, including skeletal muscle, liver, and adipose tissue, so broad activation may have varied consequences. Researchers continue to examine how selective or partial activation might alter the balance between benefits and risks.
Published human data are sparse and mostly come from early-phase trials. Those studies examined short-term changes in lipids, glucose, and exercise capacity, but they were not large enough to establish efficacy or long-term safety. Some animal experiments reported increased running endurance, yet such findings do not prove a performance benefit in people. Anti-doping laboratories detect GW501516 and its metabolites in urine or blood using liquid chromatography-tandem mass spectrometry. Detection windows depend on dose, sample type, and individual metabolism. The method is sensitive enough to identify trace residues in tested samples.
Laboratory handling focuses on identity, purity, and stability. Reference standards are typically stored cold and dry, protected from light, because solutions can degrade over time. Analytical checks may use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Impurities and related substances can be separated chromatographically and compared with a known standard. Because cardarine is not an approved drug, compendial monographs are absent, and laboratories often rely on in-house methods. Reported purity varies among unregulated products and should not be assumed from a label.
| 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 |
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.
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.
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.
In 1968, Culp also made an uncredited cameo appearance as an inebriated Turkish waiter on Get Smart, the spy-spoof comedy series, in an I Spy parody episode titled "Die Spy". In this, secret agent Maxwell Smart played by Don Adams in effect assumes Culp's Kelly Robinson character, as he pretends to be an international table-tennis champion. The episode faithfully recreates the I Spy theme music, montage graphics, and back-and-forth banter between Robinson and Scott, with actor/comedian Stu Gilliam imitating Cosby. In 1971, Culp, Peter Falk, Robert Wagner, and Darren McGavin each stepped in to take turns with Anthony Franciosa's rotation of NBC's series The Name of the Game after Franciosa was fired, alternating a lead role of the lavish, 90-minute show about the magazine business with Gene Barry and Robert Stack. Also in 1971, he portrayed an unemployed actor, the husband of ambitious Angie Dickinson, in the TV movie See the Man Run. Culp played the murderer in three Columbo episodes ("Death Lends a Hand" in 1971, "The Most Crucial Game" in 1972, "Double Exposure" in 1973) and also appeared in the 1990 episode "Columbo Goes to College" as the father of one of two young murderers. He also played the murderer in the pilot episode of Mrs. Columbo starring Kate Mulgrew in the title role. In 1973, Culp almost took the male lead in the sci-fi television series Space: 1999. During negotiations with creator and executive producer Gerry Anderson, Culp expressed himself to be not only an asset as an actor, but also as a director and producer for the proposed series.
In 2016, issues of fairness and the misuse of technology were catapulted into centre stage at machine learning conferences, publications vastly increased, funding became available, and many researchers re-focussed their careers on these issues. The alignment problem became a serious field of academic study. In 2015, AlphaGo, developed by DeepMind, beat the world champion Go player. The program taught only the game's rules and developed a strategy by itself. GPT-3 is a large language model that was released in 2020 by OpenAI and is capable of generating high-quality human-like text. ChatGPT, launched on 30 November 2022, became the fastest-growing consumer software application in history, gaining over 100 million users in two months. It marked what is widely regarded as AI's breakout year, bringing it into the public consciousness. These programs, and others, inspired an aggressive AI boom, where large companies began investing billions of dollars in AI research. According to AI Impacts, about US$50 billion annually was invested in "AI" around 2022 in the U.S. alone and about 20% of the new U.S. computer science PhD graduates have specialised in "AI". About 800,000 "AI"-related U.S. job openings existed in 2022. According to PitchBook research, 22% of newly funded startups in 2024 claimed to be AI companies.
The democratic groups—ON, PÚ, and PVVZ—united in early 1940 and formed the Central Committee of the Home Resistance (Ústřední výbor odboje domácího, ÚVOD). Involved primarily in intelligence gathering, the ÚVOD cooperated with a Soviet intelligence organization in Prague. Following the German invasion of the Soviet Union in June 1941, the democratic groups attempted to create a united front that would include the KSČ. Heydrich's appointment in the fall thwarted these efforts. By mid-1942, the Germans had succeeded in exterminating the most experienced elements of the Czechoslovak resistance forces. Czechoslovak forces regrouped in 1942–1943. The Council of the Three (R3)—in which the communist underground was also represented—emerged as the focal point of the resistance. The R3 prepared to assist the liberating armies of the U.S. and the Soviet Union. In cooperation with Red Army partisan units, the R3 developed a guerrilla structure. Guerrilla activity intensified with a rising number of parachuted units in 1944, leading to the establishment of partisan groups such as 1st Czechoslovak Partisan Brigade of Jan Žižka, Jan Kozina Brigade or Master Jan Hus Brigade, and especially after the formation of a provisional Czechoslovak government in Košice on 4 April 1945. "National committees" took over the administration of towns as the Germans were expelled. More than 4,850 such committees were formed between 1944 and the end of the war under the supervision of the Red Army.
Sources: en.wikipedia.org
==== Isomerization ==== The isomerization of uridine to pseudouridine is the second most common rRNA modification. These pseudouridines are also introduced by the same classes of snoRNPs that participate in methylation. Pseudouridine synthases are the major participating enzymes in the reaction. The H/ACA box snoRNPs introduce guide sequences that are about 14-15 nucleotides long. Pseudouridylation is triggered in numerous places of rRNAs at once to preserve the thermal stability of RNA. Pseudouridine allows for increased hydrogen bonding and alters translation in rRNA and tRNA. It alters translation by increasing the affinity of the ribosome subunit to specific mRNAs.
=== 2008–2011: Black Gives Way to Blue and death of Mike Starr === Blabbermouth.net reported on September 5, 2008, that Alice in Chains would enter the studio that October to begin recording a new album for a summer 2009 release. On September 14, 2008, Alice in Chains performed at halftime during the Seattle Seahawks vs San Francisco 49ers game at the Qwest Field (now named Lumen Field ) in Seattle. The 12-minute performance for a crowd of 67,000 people featured a cover of Led Zeppelin's "Kashmir" accompanied by the Northwest Symphony Orchestra. In October 2008, Alice in Chains began recording its fourth studio album at the Foo Fighters' Studio 606 in Los Angeles with producer Nick Raskulinecz. The band did not have a record label at the time and the album was funded by Jerry Cantrell and Sean Kinney. At the Revolver Golden God Awards, Cantrell said that the group had finished recording on March 18, 2009, and were mixing the album for a September release. The recording process was completed on Cantrell's 43rd birthday and also the same day that William DuVall's son was born. In April 2009, it was reported that the new Alice in Chains album would be released by Virgin/EMI, making it the band's first label change in its 20-plus year career. David Benveniste and his Velvet Hammer Music & Management Group began co-managing the band with Susan Silver, marking the most recent change of management and latest development to date.
=== Atlas Copco (2014-present) === The Atlas Copco Group, a Swedish multinational industrial company, acquires Edwards Vacuum. Edwards purchased Brooks Automation's CTI-Cryogenics and Polycold branded cryopump operations based in Chelmsford and Monterrey for US$675 million in 2018. In 2019, Edwards marked its 100th anniversary. Its new North America Semiconductor Technology Centre in Hillsboro opened in the same year. Edwards joined MIT.nano as a founding member, following its completion in 2018. MIT.nano is a 214,000-square-foot laboratory dedicated to the characterisation and fabrication of nanoscale materials, structures, devices, and processes. In 2020, the company opened a new Service Technology Centre in Dublin. In 2022, Edwards invested in a new facility to manufacture products for the semiconductor industry in Arizona, USA. During the same year, Edwards acquired Ceres Technologies, Inc.. Ceres is a US-based manufacturer and designer of gas and vapour delivery equipment for the semiconductor industry. It also purchased HHV Pumps Pvt Ltd, a designer and manufacturer of vacuum pumps located in Bengalaru, India, for £10.9 million. Atlas Copco also agreed to purchase the assets of Chinese, liquid ring vacuum pump manufacturer Shandong Jinggong Pump Co Ltd, to join the Edwards vacuum pump business.
=== In medicine === Medical use of alkaloid-containing plants has a long history, and, thus, when the first alkaloids were isolated in the 19th century, they immediately found application in clinical practice. Many alkaloids are still used in medicine, usually in the form of salts widely used including the following:
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.
Anti-doping and clinical laboratories commonly use liquid chromatography-tandem mass spectrometry. The method can identify GW501516 and its metabolites in urine or blood. Detection depends on sample timing and the amount present.