The short version of LC-MS/MS fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-11-29 and is reviewed periodically as new material appears.
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.
GW501516 acts as an agonist at the peroxisome proliferator-activated receptor delta, a nuclear receptor that regulates gene expression. Activation shifts transcription toward genes involved in fatty acid uptake, oxidation, and energy expenditure. The compound does not bind the androgen receptor and therefore differs from anabolic steroids and SARMs. In rodent models, this metabolic shift has been linked to increased running endurance and reduced fat accumulation. The exact downstream pathways in humans remain incompletely characterized.
Anti-doping laboratories detect GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be used in some programs. Detection depends on factors such as dose, timing, metabolism, and the sensitivity of the assay. Published methods describe limits of detection in the low nanogram per milliliter range for related compounds. Exact detection windows are not fixed for all situations and remain an area of ongoing study.
Products sold as cardarine have been found to contain incorrect compounds, variable amounts, or no active ingredient at all. Independent testing is required to verify identity and purity. Common analytical approaches include high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance for structural confirmation. These methods can distinguish GW501516 from related PPAR agonists and from unrelated steroids. For regulators and researchers, such verification is central to interpreting both biological results and adverse event reports.
Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.
| 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 |
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.
Regulatory treatment of cardarine differs by context and jurisdiction. In competitive sport, the World Anti-Doping Agency lists PPARδ agonists, including GW501516, as prohibited at all times. Outside sport, it lacks approval as a prescription medicine in major drug markets, and products sold for human consumption may be treated as unapproved drugs. Some countries also restrict importation or sale through general consumer protection and medicines laws. These classifications affect availability, testing, and legal risk without establishing therapeutic value.
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.
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.
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.
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.
==== Dispersive liquid–liquid microextraction (dLLME) ==== Dispersive liquid-liquid microextraction is process used to extract organic compounds from water samples, typically at a smaller scale than LLE using a separatory funnel. In this process, an extraction solvent immiscible with water is mixed with a dispersive solvent. The mixture is injected into the aqueous sample to be extracted, forming a dispersion of small organic droplets in the aqueous sample. The resulting suspension is then centrifuged to coalesce the organic droplets and separate the organic and aqueous layers. The organic phase can then be removed using a microsyringe or other tool. Chlorinated solvents are commonly used as the extractive solvent as their higher density makes them settle to the bottom of centrifuge tubes. Acetone is a common dispersive solvent. dLLME is favored for its relatively low use of organic solvent for a batch extraction process which can reduce costs. The lower solvent usage means dLLME can be considered a "green chemistry" process though common use of chlorinated solvents as the organic phase is typically considered antithetical to green chemistry principles. This process is useful in extraction organic compounds such as organochloride and organophosphorus pesticides, as well as substituted benzene compounds from water samples.
=== General features === Although the tetrahedral intermediates are usually transient intermediates, many compounds of this general structures are known. The reactions of aldehydes, ketones, and their derivatives frequently have a detectable tetrahedral intermediate, while for the reactions of derivatives of carboxylic acids this is not the case. At the oxidation level of carboxylic acid derivatives, the groups such as OR, OAr, NR2, or Cl are conjugated with the carbonyl group, which means that addition to the carbonyl group is thermodynamically less favored than addition to corresponding aldehyde or ketone. Stable tetrahedral intermediates of carboxylic acid derivatives do exist and they usually possess at least one of the following four structural features:
Bush publicly condemned Kim Jong-il of North Korea and identified North Korea as one of three states in an "axis of evil". He said that "the United States of America will not permit the world's most dangerous regimes to threaten us with the world's most destructive weapons." Within months, "both countries had walked away from their respective commitments under the U.S.–DPRK Agreed Framework of October 1994." North Korea's October 9, 2006, detonation of a nuclear device further complicated Bush's foreign policy, which centered for both terms of his presidency on "[preventing] the terrorists and regimes who seek chemical, biological, or nuclear weapons from threatening the United States and the world". Bush condemned North Korea's position, reaffirmed his commitment to "a nuclear-free Korean Peninsula", and said that "transfer of nuclear weapons or material by North Korea to states or non-state entities would be considered a grave threat to the United States", for which North Korea would be held accountable. On May 7, 2007, North Korea agreed to shut down its nuclear reactors immediately pending the release of frozen funds held in a foreign bank account. This was a result of a series of three-way talks initiated by the United States and including China. On September 2, 2007, North Korea agreed to disclose and dismantle all its nuclear programs by the end of 2007. By May 2009, North Korea had restarted its nuclear program and threatened to attack South Korea.
=== Helix structure === In 1948, Pauling discovered that many proteins included helical (see alpha helix) shapes. Pauling had deduced this structure from X-ray patterns and from attempts to physically model the structures. (Pauling was also later to suggest an incorrect three chain helical DNA structure based on Astbury's data.) Even in the initial diffraction data from DNA by Maurice Wilkins, it was evident that the structure involved helices. But this insight was only a beginning. There remained the questions of how many strands came together, whether this number was the same for every helix, whether the bases pointed toward the helical axis or away, and ultimately what were the explicit angles and coordinates of all the bonds and atoms. Such questions motivated the modeling efforts of Watson and Crick.
Sources: en.wikipedia.org
ethylenediamine (en) Nitrilotriacetic acid (NTA) aminopolycarboxylic acids (complexones) Alpha hydroxy acids and other hydroxycarboxylic acids crown ethers phosphonic acids imidazoles and histamines amino acids with polar side-chains nucleotides acetylacetone general Chemical speciation of environmentally significant heavy metals with inorganic ligands. Part 1: The Hg2+–Cl−, OH−, CO2−3, SO2−4, and PO3−4 systems. Chemical speciation of environmentally significant metals with inorganic ligands Part 2: The Cu2+–OH−, Cl−, CO2−3, SO2−4, and PO3−4 aqueous systems Chemical speciation of environmentally significant metals with inorganic ligands Part 3: The Pb2+–OH−, Cl−, CO2−3, SO2−4, and PO3−4 systems Chemical speciation of environmentally significant metals with inorganic ligands. Part 4: The Cd2+–OH−, Cl−, CO2−3, SO2−4, and PO3−4 systems
=== Surface energy measurement === In industrial corona and plasma processes, cost-efficient and rapid analytical methods are required for confirming adequate surface functionality on a given substrate. Measuring the surface energy is an indirect method for confirming the presence of surface functional groups without the need for microscopy or spectroscopy, often expensive and demanding tools. Contact angle measurement (goniometry) can be used to find the surface energy of the treated and non-treated surface. Young's relation can be used to find surface energy assuming the simplification of experimental conditions to a three phase equilibrium (i.e. liquid drop applied to flat rigid solid surface in a controlled atmosphere), yielding
=== Detection in urine === Researchers found that humans who smoked 580 μg of the pure drug had urine salvinorin A concentrations of 2.4–10.9 μg/L during the first hour; the levels fell below the detection limit by 1.5 hours after smoking.
Sources: en.wikipedia.org
== Early life and education == Born in Berlin, to a Jewish family, his family home was located on Reichskanzlerplatz, renamed “Adolf Hitler Platz” after Hitler's ascent to power, and then Theodor Heuss Platz after the Second World War. Both of his parents (Alfred and Kaethe, née Italiener) were physicians. His mother, a pediatrician, was in pre-war times the physician to Harald Quandt, son of Magda Quandt née Rietschel, later Magda Goebbels, wife of the German propaganda minister. The second of three children, Beutler was preceded by an older brother, Frederick (b. October 3, 1926, later a professor of mathematics at the University of Michigan), and followed by a younger sister, Ruth (b. November 23, 1932, later a clinical psychologist; d. July 14, 1993). In 1935, when Beutler was seven years of age, the family emigrated to the United States to escape Nazi persecution. Beutler was raised in Milwaukee, Wisconsin. At 15, Beutler enrolled in a special program at the University of Chicago, founded by Robert Hutchins, then President of the University. He completed his undergraduate, medical school and residency training at the University of Chicago, receiving his doctorate in medicine in 1950 at the age of 21. He was a member of Pi Lambda Phi and the valedictorian of his graduating class.
Cardiovascular: dyslipidemia (e.g., increased LDLTooltip low-density lipoprotein levels, decreased HDLTooltip high-density lipoprotein levels, reduced apo-A1Tooltip apolipoprotein A1 levels), atherosclerosis, elevated hematocrit, hypertension, left ventricular hypertrophy, cardiomyopathy, myocardial hypertrophy, polycythemia/erythrocytosis, arrhythmias, thrombosis (e.g., embolism, stroke), myocardial infarction, sudden death. Hepatic: elevated liver function tests (ASTTooltip aspartate aminotransferase, ALTTooltip alanine aminotransferase, bilirubin, LDHTooltip lactic dehydrogenase, ALPTooltip alkaline phosphatase), hepatotoxicity, jaundice, hepatic steatosis, hepatocellular adenoma, hepatocellular carcinoma, cholestasis, peliosis hepatis; all mostly or exclusively with 17α-alkylated AAS. Renal: renal hypertrophy, nephropathy, acute renal failure (secondary to rhabdomyolysis), focal segmental glomerulosclerosis, renal cell carcinoma. Others: glucose intolerance, insulin resistance, immune dysfunction.
=== 2023 unexcused absences === While participating in a Republican-led walkout in May 2023 Robinson reached the 10 unexcused absence threshold set by measure 113, disqualifying him from running for reelection after his current term ends. In October the Oregon Supreme Court agreed to hear a challenge to the measure. On February 1, 2024, the Court unanimously ruled against the Republican Senators, confirming Robinson's disqualification after the end of his term in January 2025. Robinson was succeeded in the Senate by his son, Noah Robinson.
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.
Legal status varies by country, but cardarine is not approved as a medicine in major jurisdictions. It is often sold as a research chemical, a category that may not be lawful for human use. Buyers should check local laws and product labels carefully.