LC-MS/MS comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-01-08. Where a claim depends on a specific study, the study is described rather than over-claimed.
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
Cardarine is a common name for GW501516, a synthetic compound studied for its effects on lipid and glucose metabolism. It functions as an agonist at peroxisome proliferator-activated receptor delta, or PPARδ, a nuclear receptor that influences gene expression. The molecule is not a steroid, nor is it a selective androgen receptor modulator. It is also known in research and sports literature as GW-501516 and endurobol. Early laboratory work examined its metabolic activity in cell cultures and animal models.
Activation of PPARδ changes transcription of genes involved in fatty acid transport, mitochondrial function, and skeletal muscle fuel preference. In rodent studies, pharmacological PPARδ activation was associated with increased endurance and altered body composition. These findings generated interest in performance enhancement, but species differences and study designs limit direct extrapolation to humans. Small human trials were conducted in the 2000s and later discontinued. The extent to which cardarine produces similar metabolic or performance effects in people remains an open question.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic PPARδ agonist | Not a steroid or a selective androgen receptor modulator. |
| Common synonyms | Cardarine, GW501516, GW-501516, endurobol | Names vary by supplier and literature source. |
| Appearance | White to off-white powder | Consistent with many small-molecule research chemicals. |
| Solubility | Low in water; soluble in DMSO and ethanol | Often prepared in organic solvent for laboratory work. |
| Primary target | PPARδ (NR1C2) | Nuclear receptor involved in lipid and energy metabolism. |
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.
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.
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.
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.
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.
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.
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.
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.
In their annual violent crime index for the year 2001, the FBI recorded the deaths from the attacks as murder, in separate tables so as not to mix them with other reported crimes for that year. In a disclaimer, the FBI stated that "the number of deaths is so great that combining it with the traditional crime statistics will have an outlier effect that falsely skews all types of measurements in the program's analyses." New York City also did not include the deaths in their annual crime statistics for 2001.
Samples are dissolved or suspended in a "cocktail" containing a solvent (historically aromatic organics such as xylene or toluene, but more recently less hazardous solvents are used), typically some form of a surfactant, and "fluors" or scintillators which produce the light measured by the detector. Scintillators can be divided into primary and secondary phosphors, differing in their luminescence properties. Beta particles emitted from the isotopic sample transfer energy to the solvent molecules: the π cloud of the aromatic ring absorbs the energy of the emitted particle. The energized solvent molecules typically transfer the captured energy back and forth with other solvent molecules until the energy is finally transferred to a primary scintillator. The primary phosphor will emit photons following absorption of the transferred energy. Because that light emission may be at a wavelength that does not allow efficient detection, many cocktails contain secondary phosphors that absorb the fluorescence energy of the primary phosphor and re-emit at a longer wavelength. Two widely used primary and secondary fluors are 2,5-diphenyloxazole (PPO) with an emission maximum of 380 nm and 1,4-bis-2-(5-phenyloxazolyl)benzene (POPOP) with an emission maximum of 420 nm. The radioactive samples and cocktail are placed in small transparent or translucent (often glass or plastic) vials that are loaded into an instrument known as a liquid scintillation counter. Newer machines may use 96-well plates with individual filters in each well.
Nelotanserin (former developmental code name APD-125) is a drug developed by Arena Pharmaceuticals which acts as an inverse agonist on the serotonin receptor subtype 5-HT2A and was under development for the treatment of insomnia. It was shown to be effective and well tolerated in clinical trials, but development was halted in December 2008 because the substance did not meet the trial's effectiveness endpoints. Research continues on newer analogues which may potentially be more successful.
=== Therapeutics === Because it is abundant, of human origin, and easy to grow, L. plantarum has been tested for health effects. It has been identified as a probiotic, which suggests its value for further research and application. L. plantarum has significant antioxidant activities and also helps to maintain intestinal permeability. It is able to suppress the growth of gas-producing bacteria in the intestines and may benefit some patients who suffer from IBS. It helps to create microbe balance and stabilize digestive enzyme patterns. Lactiplantibacillus plantarum has been found in experiments to increase hippocampal brain derived neurotrophic factor, which means L. plantarum may have a beneficial role in the treatment of depression. The ability of L. plantarum to survive in the human gastro-intestinal tract makes it a possible in vivo delivery vehicle for therapeutic compounds or proteins. Lactiplantibacillus plantarum is a constituent in VSL#3. This proprietary, standardized formulation of live bacteria may be used in combination with conventional therapies to treat ulcerative colitis and requires a prescription.
The concept of a "Fortress North America" emerged during the Second World War and persisted into the Cold War to refer to the option of defending Canada and the United States against their enemies if the rest of the world were lost to them. This option was rejected with the formation of NATO and the decision to permanently station troops in Europe. In the summer of 1951, Project Vista started, in which project analysts such as Robert F. Christy looked at how to defend Western Europe from a Soviet invasion. The emerging development of tactical nuclear weapons was looked upon as a means to give Western forces a qualitative advantage over the Soviet numerical supremacy in conventional weapons. Several scares about the increasing ability of the Soviet Union's strategic bomber forces surfaced during the 1950s. The defensive response by the United States was to deploy a fairly strong "layered defense" consisting of interceptor aircraft and anti-aircraft missiles, like the Nike, and guns, like the M51 Skysweeper, near larger cities. However, this was a small response compared to the construction of a huge fleet of nuclear bombers. The principal nuclear strategy was to massively penetrate the Soviet Union. Because such a large area could not be defended against this overwhelming attack in any credible way, the Soviet Union would lose any exchange. This logic became ingrained in American nuclear doctrine and persisted for much of the duration of the Cold War.
Sources: en.wikipedia.org
ASR-2001 (2CB-5PrO) is a propoxy TWEETIO and another notable analogue of 2C-B which is under development for treatment of psychiatric disorders. FLY derivatives of 2C-B like 2C-B-FLY, 2C-B-DRAGONFLY, and 2C-B-BUTTERFLY are analogues in which the methoxy groups of 2C-B on the phenyl ring have been cyclized into furan or other rings to form benzodifuran and other tricyclic compounds. 2-OH-2C-B is the 2-O-desmethylated analogue of 2C-B and shows similar potency as a serotonin 5-HT2A receptor agonist in vitro. Cyclized phenethylamine derivatives of 2C-B in which the side chain has been cyclized in some way include DOB-CR (2C-B-CR), 2CB-Ind, 2C-B-5-hemiFLY-α6 (BNAP), 2CB7 (2C-B-5-hemiFLY-β7), TCB-2 (2CBCB), 2C-B-PYR, 2C-B-3PIP, 2C-B-3PIP-NBOMe, 2C-B-3PIP-POMe, 2CBecca, 2CJP, 2CLisaB, ZC-B, 2C-B-aminorex (2C-B-AR), and 2C-B-morpholine (2C-B-MOR), among others. Other related cyclized compounds, while not technically phenethylamines or 2C-B derivatives, include 2C-B-BZP and 2C-B-PP. A notable positional isomer of 2C-B is the scaline and mescaline analogue 4-bromomescaline (4-Br-3,5-DMPEA). Deuterated isotopologues of 2C-B such as 2CB-2OCD3 (2-trideuteromethoxy-2C-B), 2CB-5OCD3 (5-trideuteromethoxy-2C-B), and hexadeutero-2C-B (2,5-di(trideuteromethoxy)-2C-B) among others have been described.
== Concept and creation == Headcrabs are a race of dog-sized alien creatures that leap at people's heads in order to latch onto them and turn them into zombie-like creatures that move slowly. Headcrab-controlled zombies are suggested to retain the capacity for intelligence and emotion without the ability to properly express it. When they regain control after the Headcrab is killed, they are able to speak before death; for instance, when set on fire, the host can say "I am burning. Please God, kill me. I am burning". Early prototypes for the Headcrabs gave them butts and were colored "faecal brown". The first Half-Life features the standard Headcrab, while Half-Life 2 introduces two new Headcrab variations: the fast Headcrab, which creates fast zombies, and the Poison Headcrab, which creates slower and more durable zombies. When designing Half-Life: Alyx, the team was in two camps, with the ability for a Headcrab to jump at the player's face in virtual reality being the reason some supported it and others opposed it. When designing the Headcrab in this game, it was designed to have a percentage chance for it to miss in its leap, thinking this made them more fun to interact with.
=== Allatostatin A === Allatostatin A (AstA) peptides are found in all arthropods and contain a C-terminus Y/FXFGLamide. In Drosophila, there are 4 AstA peptides (AstA-1, AstA-2, AstA-3, AstA-4) and 2 AstA receptors (AstA-R1 and AstA-R2). The AstA receptor is a GIRK1 channel and is homologous to the mammalian galanin receptor
The way our fellows charged their way along these paths, yelling, makes a lump come into my throat when I think of it even now. It was sheer suicide for the leading group and the whole force faced machine guns up the sides of the slopes above them, on the sides of the features behind them, and even up the trees above them, with snipers behind who let them pass before opening fire. For sheer cold-blooded bravery, I can't believe it has ever been beaten in any other theatre of war; and this went on for three weeks solid. 1RAR spent most of May 1945 building quarters and training before marching the 110 km (68 mi) to Prome in late June; from here they went another 25 km (16 mi) by truck to Gyobingauk. The monsoon conditions took a dreadful toll on operations, making logistics particularly difficult and slow—men found themselves either found themselves knee-deep in mud or slipping around on the surface. From early July 1945 1RAR patrolled around Gyobingauk, repeatedly engaging parties of Japanese and forcing them into the hills. Even after the Japanese commanders in Burma surrendered unconditionally, the Allied troops had to continue patrolling to handle Japanese stragglers who either did know of this or did not believe it. After the Japanese forces in South-East Asia formally surrendered at Singapore on 12 September 1945, active Allied operations in the region were greatly diminished. 1RAR spent about half a year guarding Japanese prisoners in Burma before leaving for home in March 1946. They arrived back in Salisbury on 10 May.
=== Lactones === gamma-Decalactone intense peach flavor gamma-Nonalactone coconut odor, popular in suntan lotions delta-Octalactone creamy note Jasmine lactone powerful fatty-fruity peach and apricot Massoia lactone powerful creamy coconut Wine lactone sweet coconut odor Sotolon (maple syrup, curry, fenugreek)
Sources: en.wikipedia.org
== Clinical significance == Within this section, the function of CK1δ in the occurrence, development and progress of several diseases and disorders mainly on cancers, neurological diseases and metabolic diseases will be discussed.
They were treated for about four years and gained 4-8 cm in adult height. Controversy has arisen as to whether all of these children were truly "short normal" children, since the average IGF1 was low. Approval of HGH for the treatment of this extreme degree of shortness led to an increase in the number of parents seeking its use to make otherwise normal children a little taller.
The party also established various "sectorial organizations", including a student union (Organización Democrática de Estudiantes Antifascistas), a prisoner-support group (Asociación de Familiares y amigos de Presos) and an "antirrepresie" organization (Socorro Rojo). Despite its initial successes, the PCE(r) became increasingly a marginal group after certain key-measures were adopted by the transitional Spanish government. Foremost of these were the 1977 amnesty for political prisoners, the democratic normalization, and the growing success of the newly introduced measures adopted by the Spanish police and the Spanish courts to combat terrorism. After the issuing of a new law concerning political parties in 2002, the Spanish authorities severely curtailed the activities of the PCE(r) in 2003. Currently the party is outlawed, although still exists as a clandestine organization. Historically, the strongholds of the party have been Vigo, Cádiz, A Coruña and El Pozo del Tio Raimundo.
Flies use a modified version of Bloom filters to detect novelty of odors, with additional features including similarity of novel odor to that of previously experienced examples, and time elapsed since previous experience of the same odor.
Sources: en.wikipedia.org
Cardarine is a common name for GW501516, a synthetic PPARδ agonist. It is not a steroid or a selective androgen receptor modulator. It was developed and studied as a research compound for metabolic pathways.
It binds to and activates PPARδ, a nuclear receptor that regulates genes related to fatty acid oxidation and energy use. This activation alters transcription in tissues such as skeletal muscle and liver. The full range of downstream effects in humans is not fully established.
No, cardarine is not known to occur naturally in plants, animals, or humans. It is a synthetic molecule produced for laboratory research. Products labeled as cardarine should therefore be treated as manufactured chemicals with variable purity.
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.