A practical reference on LC-MS/MS: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-10-04 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.
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.
| 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 |
Quality assessment for cardarine samples usually combines identity, purity, and impurity testing. Nuclear magnetic resonance spectroscopy and mass spectrometry can confirm molecular structure, while high-performance liquid chromatography estimates purity. Certificates of analysis from testing laboratories may list these results, but they do not establish safety or legality. In the absence of approved manufacturing, products sold online may contain the wrong compound, variable amounts, or unlisted contaminants. Independent verification is therefore central to analytical work and to interpreting any reported biological activity.
Laboratory detection of GW501516 commonly uses liquid chromatography coupled with tandem mass spectrometry. The method can identify the parent compound or its metabolites in urine and blood after sample cleanup. Protein precipitation, solid-phase extraction, or enzymatic hydrolysis may precede analysis, depending on the matrix. Reference standards are required for accurate quantification and confirmation. Because the compound is not approved, testing often occurs in anti-doping, forensic, or research settings rather than routine clinical care. Results are reported with limits of detection and quantification.
Stability of GW501516 depends on form, temperature, light exposure, and moisture. Solid reference material is typically stored frozen or refrigerated in a desiccator and protected from light. Solutions in organic solvents such as dimethyl sulfoxide are often kept frozen in aliquots to reduce freeze-thaw cycling. Aqueous solubility is low, so aqueous stock solutions can be difficult to prepare without cosolvents. Degradation may appear as changes in chromatographic purity or mass spectral signal. Stability studies are needed to establish shelf life for any specific preparation.
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.
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.
Because cardarine is not an approved medicine, no pharmacopeial monograph defines its identity, purity, or storage requirements. Laboratories typically rely on in-house methods and reference standards when testing materials labeled as GW501516. Certificates of analysis may report purity and identity for a specific batch, but their scope varies and they do not guarantee safety or legal status. Independent verification can include high-performance liquid chromatography, mass spectrometry, nuclear magnetic resonance, and elemental analysis. The distinction between research chemical labeling and human use is significant because quality standards and oversight differ.
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.
=== Amines === Amines follow nitrogen rule. Odd molecular ion mass-to-charge ratio suggests existence of odd numbers of nitrogens. Nonetheless, molecular ion peaks are weak in aliphatic amines due to the ease of fragmentation next to amines. Alpha-cleavage reactions are the most important fragmentation mode for amines; for 1° n-aliphatic amines, there is an intense peak at m/z 30.
It is typically used to quantify drug, disease, and trial information to aid efficient drug development, regulatory decisions, and rational drug treatment in patients. Pharmacometrics uses models based on pharmacology, physiology, and disease for quantitative analysis of interactions between drugs and patients. This involves Systems pharmacology, pharmacokinetics, pharmacodynamics and disease progression with a focus on populations and variability. Mould and Upton provide an overview of basic concepts in population modeling, simulation, and model-based drug development.
=== Other websites === TikTok is now the dominant social media platform amongst the newer generation. The popularity of TikTok has led various other web services to adopt similar features in order to compete with TikTok. Instagram launched a short, vertical videos section called Instagram Reels to its app in 2020. YouTube followed with the release of YouTube Shorts in 2021. In 2022, Facebook launched a videos tab on its app that shows users a personalized selection of videos. The same year, Twitter announced that it would also be launching a short videos feature and Amazon added a scrolling feed with photos and videos of available products to its mobile app. In 2023, Spotify redesigned its home screen to have a similar scrolling interface to TikTok and Reddit also added a separate video feed to its mobile app.
=== Branched polymers === A monomer with functionality of 3 or more will introduce branching in a polymer and will ultimately form a cross-linked macrostructure or network even at low fractional conversion. The point at which a tree-like topology transits to a network is known as the gel point because it is signalled by an abrupt change in viscosity. One of the earliest so-called thermosets is known as Bakelite. It is not always water that is released in step-growth polymerization: in acyclic diene metathesis or ADMET, dienes polymerize with loss of ethene.
The Soviet Zond spacecraft was not yet ready for piloted circumlunar missions in 1968, after six unsuccessful automated test launches: Kosmos 146 on March 10, 1967; Kosmos 154 on April 8, 1967; Zond 1967A on September 28, 1967; Zond 1967B on November 22, 1967; Zond 1968A on April 23, 1968; and Zond 1968B in July 1968. Zond 4 was launched on March 2, 1968, and successfully made a circumlunar flight, but encountered problems with its Earth reentry on March 9, and was ordered destroyed by an explosive charge 15,000 meters (49,000 ft) over the Gulf of Guinea. The Soviet official announcement said that Zond 4 was an automated test flight which ended with its intentional destruction, due to its recovery trajectory positioning it over the Atlantic Ocean instead of over the USSR. During the summer of 1968, the Apollo program hit another snag: the first pilot-rated Lunar Module (LM) was not ready for orbital tests in time for a December 1968 launch. NASA planners overcame this challenge by changing the mission flight order, delaying the first LM flight until March 1969, and sending Apollo 8 into lunar orbit without the LM in December. This mission was in part motivated by intelligence rumors the Soviet Union might be ready for a piloted Zond flight in late 1968. In September 1968, Zond 5 made a circumlunar flight with tortoises on board and returned safely to Earth, accomplishing the first successful water landing of the Soviet space program in the Indian Ocean.
Sources: en.wikipedia.org
== Signs and symptoms == Rheumatoid arthritis (RA) is a chronic autoimmune disorder that can affect multiple organ systems. It mainly affects fluid filled connections between joints (synovial joints), causing inflammation, pain, and stiffness in the joints. RA also affects other organs in 20–40% of people. RA typically develops slowly and affects both sides of the body. Systemic symptoms such as fatigue, low-grade fevers and weight loss are also seen in RA.
== Toxicity == The short-term lethal dose of melamine is on a par with common table salt, with an LD50 of more than 3 grams per kilogram of bodyweight. U.S. Food and Drug Administration (FDA) scientists explained that when melamine and cyanuric acid are absorbed into the bloodstream, they concentrate and interact in the urine-filled renal tubules, then crystallize and form large numbers of round, yellow crystals, which in turn block and damage the renal cells that line the tubes, causing the kidneys to malfunction and lead to kidney stones, kidney failure, and death. Signs of melamine toxicity can include irritability, blood in the urine, little to no urine, symptoms of kidney infection, or high blood pressure. The European Union set a standard for acceptable human consumption (tolerable daily intake or TDI) of melamine at 0.2 mg per kilogram of body mass (previously 0.5 mg/kg), Canada declared a limit of 0.35 mg/kg, and the US FDA's limit was put at 0.063 mg/kg (previously 0.63 mg/kg). The World Health Organization's food safety director estimated that the amount of melamine a person could stand per day without incurring a bigger health risk, the TDI, was 0.2 mg per kilogram of body mass. Toxicity of melamine can be mediated by intestinal microbiota. In culture, Raoultella terrigena, which rarely colonizes mammalian intestines, was shown to convert melamine to cyanuric acid directly. Rats colonized by R. terrigena showed greater melamine-induced kidney damage compared to those not colonized.
S100 calcium-binding protein A12 (S100A12) is a protein that in humans is encoded by the S100A12 gene. Human S100A12, also known as calgranulin C, was first described in 1995. The protein encoded by this gene is a member of the S100 family of proteins containing 2 EF-hand calcium-binding motifs.
Unstable angina is a type of angina pectoris that is irregular or more easily provoked. It is classified as a type of acute coronary syndrome. It can be difficult to distinguish unstable angina from non-ST elevation (non-Q wave) myocardial infarction. They differ primarily in whether the ischemia is severe enough to cause sufficient damage to the heart's muscular cells to release detectable quantities of a marker of injury, typically troponin T or troponin I. Unstable angina is considered to be present in patients with ischemic symptoms suggestive of an acute coronary syndrome and no change in troponin levels, with or without changes indicative of ischemia (e.g., ST segment depression or transient elevation or new T wave inversion) on electrocardiograms.
=== Prosecution in Panama === Noriega was tried in absentia in Panama for crimes committed during his rule. In October 1993 Noriega and two others were convicted of the murder of Spadafora by the court of the Third Judicial District, and sentenced to 20 years in prison. Panama's Supreme Court confirmed the sentence on December 20, 1995. In 1994, Noriega and Heráclides Sucre, an agent of his secret police, were convicted by a jury of the murder of Giroldi, who had led the 1989 coup attempt against Noriega. Though Noriega was tried in absentia, a judge traveled to the U.S. to question him in December 1993. Noriega and Sucre both received a 20-year sentence, the maximum penalty sought by the prosecutor. Finally, Noriega received a third 20-year sentence in 1996 for his role in the death of nine military officers supporting Giroldi; the group had been executed in a hangar at the Albrook air base after the coup attempt, in an incident that came to be known as the massacre of Albrook. Noriega was also prosecuted over the 1968 disappearances of Luis Antonio Quirós and Everett Clayton Kimble Guerra in Chiriquí, and the 1971 death of Heliodoro Portugal. These cases had not reached a conclusion at the time of his death in 2017.
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.
No. Cardarine has not received approval for human therapeutic use in major jurisdictions. It remains an investigational compound.