If you have been reading about LC-MS/MS and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-07-24. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 |
|---|---|---|
| Common name | Cardarine | Also called GW501516 and endurobol. |
| Chemical formula | C21H18F3NO3S2 | Molecular weight about 453.5 g/mol. |
| Appearance | White to off-white solid | Form depends on synthesis and purity. |
| Solubility | Soluble in DMSO and ethanol | Low solubility in water. |
| Typical storage | -20 °C, desiccated, protected from light | Common for research chemicals. |
Laboratory detection of cardarine typically involves sample preparation followed by chromatographic separation and mass spectrometric identification. Urine is the most common matrix for anti-doping tests, though blood and hair have also been explored. Methods can target the parent compound or its metabolites, depending on the expected window of detection. Reference standards are required for accurate quantification. Matrix effects and dilution can influence results, so laboratories use internal standards and validation protocols. The exact detection window varies with dose, route, and individual metabolism.
A common misconception is that cardarine has been proven safe for human use. In reality, human clinical data are limited, and long-term animal studies have raised concerns about cancer. Another misconception is that it is a supplement or vitamin-like compound. It is a synthetic research chemical with no approved medical indication. Scientific discussion often focuses on its mechanism and detection rather than therapeutic use. Regulatory and anti-doping literature treats it primarily as a prohibited substance.
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.
Teleosts possess highly developed sensory organs. Nearly all daylight fish have colour vision at least as good as a normal human's. Many fish also have chemoreceptors responsible for acute senses of taste and smell. Most fish have sensitive receptors that form the lateral line system, which detects gentle currents and vibrations, and senses the motion of nearby fish and prey. Fish sense sounds in a variety of ways, using the lateral line, the swim bladder, and in some species the Weberian apparatus. Fish orient themselves using landmarks, and may use mental maps based on multiple landmarks or symbols. Experiments with mazes show that fish possess the spatial memory needed to make such a mental map.
== Pathophysiology == Ketones are primarily produced from free fatty acids in the mitochondria of liver cells. The production of ketones is strongly regulated by insulin and an absolute or relative lack of insulin underlies the pathophysiology of ketoacidosis. Insulin is a potent inhibitor of fatty acid release, so insulin deficiency can cause an uncontrolled release of fatty acids from adipose tissue. Insulin deficiency can also enhance ketone production and inhibit peripheral use of ketones. This can occur during states of complete insulin deficiency (such as untreated diabetes) or relative insulin deficiency in states of elevated glucagon and counter-regulatory hormones (such as starvation, heavy chronic alcohol use or illness). Acetoacetic acid and β-hydroxybutyrate are the most abundant circulating ketone bodies. Ketone bodies are acidic; however, at physiologic concentrations, the body's acid/base buffering system prevents them from changing blood pH.
== History == The concept of the regulation of the internal environment was described by French physiologist Claude Bernard in 1849, and the word homeostasis was coined by Walter Bradford Cannon in 1926. In 1932, Joseph Barcroft, a British physiologist, was the first to say that higher brain function required the most stable internal environment. Thus, to Barcroft homeostasis was not only organized by the brain—homeostasis served the brain. Homeostasis is an almost exclusively biological term, referring to the concepts described by Bernard and Cannon, concerning the constancy of the internal environment in which the cells of the body live and survive. The term cybernetics is applied to technological control systems such as thermostats, which function as homeostatic mechanisms but are often defined much more broadly than the biological term of homeostasis.
Sources: en.wikipedia.org
=== Optic neuritis === HHV-6 induced ocular inflammation has been reported three times. All three were reported in elderly individuals, two during 2007 and one during 2011. The first two were reported in Japan and France, the most recent one in Japan. These were believed to have occurred as a result of a reactivation, as anti-HHV-6 IgM antibody levels were low.
dephosphorylation The removal of a phosphate group, PO3−4, from a chemical compound, protein, or other biomolecule, either spontaneously or by enzymatic catalysis. Dephosphorylation is the opposite of phosphorylation; both reactions are common molecular modifications involved in numerous biochemical pathways and processes, including in metabolism, where high-energy bonds to phosphate groups are used to transfer energy between molecules, and in the post-translational modification of proteins, where the phosphorylation state of particular residues can affect the protein's affinity for other molecules or function as a molecular signal.
=== Effects on human performance === Most reviews conclude that opioids produce minimal impairment of human performance on tests of sensory, motor, or attentional abilities. However, recent studies have been able to show some impairments caused by morphine, which is not surprising, given that morphine is a central nervous system depressant. Morphine has resulted in impaired functioning on critical flicker frequency (a measure of overall CNS arousal) and impaired performance on the Maddox wing test (a measure of the deviation of the visual axes of the eyes). Few studies have investigated the effects of morphine on motor abilities; a high dose of morphine can impair finger tapping and the ability to maintain a low constant level of isometric force (i.e. fine motor control is impaired), though no studies have shown a correlation between morphine and gross motor abilities. In terms of cognitive abilities, one study has shown that morphine may negatively impact anterograde and retrograde memory, but these effects are minimal and transient. Overall, it seems that acute doses of opioids in non-tolerant subjects produce minor effects in some sensory and motor abilities, and perhaps also in attention and cognition. The effects of morphine will likely be more pronounced in opioid-naive subjects than in chronic opioid users. In chronic opioid users, such as those on Chronic Opioid Analgesic Therapy (COAT) for managing severe, chronic pain, behavioural testing has shown normal functioning on perception, cognition, coordination, and behaviour in most cases.
A denturist in the United States and Canada, clinical dental technologist in the United Kingdom and Ireland, dental prosthetist in Australia, or a clinical dental technician in New Zealand is a member of the oral health care team and role as primary oral health care provider who provides an oral health examination, planning treatment, takes impressions of the surrounding oral tissues, constructs and delivers removable oral prosthesis treatment (including dentures and partial dentures) directly to the patient.
Sources: en.wikipedia.org
The survival of paregoric through the centuries, and particularly through recent critical decades, is probably due to keen clinical observation and stubborn adherence to the clinical deduction that paregoric is useful in certain types of cough.
== Chemistry == Bulevirtide is a 47-amino acid long lipopeptide with the following sequence: CH3(CH2)12CO-Gly-Thr-Asn-Leu-Ser-Val-Pro-Asn-Pro-Leu-Gly-Phe-Phe-Pro-Asp-His-Gln-Leu-Asp-Pro-Ala-Phe-Gly-Ala-Asn-Ser-Asn-Asn-Pro-Asp-Trp-Asp-Phe-Asn-Pro-Asn-Lys-Asp-His-Trp-Pro-Glu-Ala-Asn-Lys-Val-Gly-NH2 (C13H27CO-GTNLSVPNPLGFFPDHQLDPAFGANSNNPDWDFNPNKDHWPEANKVG-NH2)
== Distribution among organisms == The large majority of known organisms use catalase in every organ, with particularly high concentrations occurring in the liver in mammals. Catalase is found primarily in peroxisomes and the cytosol of erythrocytes (and sometimes in mitochondria) Almost all aerobic microorganisms use catalase. It is also present in some anaerobic microorganisms, such as Methanosarcina barkeri. Catalase is also universal among plants and occurs in most fungi. One unique use of catalase occurs in the bombardier beetle. This beetle has two sets of liquids that are stored separately in two paired glands. The larger of the pair, the storage chamber or reservoir, contains hydroquinones and hydrogen peroxide, while the smaller, the reaction chamber, contains catalases and peroxidases. To activate the noxious spray, the beetle mixes the contents of the two compartments, causing oxygen to be liberated from hydrogen peroxide. The oxygen oxidizes the hydroquinones and also acts as the propellant. The oxidation reaction is very exothermic (ΔH = −202.8 kJ/mol) and rapidly heats the mixture to the boiling point. Long-lived queens of the termite Reticulitermes speratus have significantly lower oxidative damage to their DNA than non-reproductive individuals (workers and soldiers). Queens have more than two times higher catalase activity and seven times higher expression levels of the catalase gene RsCAT1 than workers. It appears that the efficient antioxidant capability of termite queens can partly explain how they attain longer life.
The algae are a heterogeneous group of mostly photosynthetic organisms that produce oxygen and lack the reproductive features and structural complexity of land plants. This concept includes the cyanobacteria, which are prokaryotes, and all photosynthetic protists, which are eukaryotes. They contain chlorophyll a as their primary photosynthetic pigment, and generally inhabit aquatic environments. However, there are many exceptions to this definition. Many non-photosynthetic protists are included in the study of algae, such as the heterotrophic relatives of euglenophytes or the numerous species of colorless algae that have lost their chlorophyll during evolution (e.g., Prototheca). Some exceptional species of algae tolerate dry terrestrial habitats, such as soil, rocks, or caves hidden from light sources, although they still need enough moisture to become active.
== Physiological effects == The adrenal medulla is a major contributor to total circulating catecholamines (L-DOPA is at a higher concentration in the plasma), though it contributes over 90% of circulating adrenaline. Little adrenaline is found in other tissues, mostly in scattered chromaffin cells and in a small number of neurons that use adrenaline as a neurotransmitter. Following adrenalectomy, adrenaline disappears below the detection limit in the bloodstream. Pharmacological doses of adrenaline stimulate α1, α2, β1, β2, and β3 adrenoceptors of the sympathetic nervous system. Sympathetic nerve receptors are classified as adrenergic, based on their responsiveness to adrenaline. The term "adrenergic" is often misinterpreted in that the main sympathetic neurotransmitter is noradrenaline, rather than adrenaline, as discovered by Ulf von Euler in 1946. Adrenaline has a β2 adrenoceptor-mediated effect on metabolism and the airway, with no direct neural connection from the sympathetic ganglia to the airway. Walter Bradford Cannon originally proposed the concept of the adrenal medulla and the sympathetic nervous system being involved in the flight, fight, and fright response. But the adrenal medulla, in contrast to the adrenal cortex, is not required for survival. In adrenalectomized patients, hemodynamic and metabolic responses to stimuli such as hypoglycemia and exercise remain normal.
Sources: en.wikipedia.org
Cardarine is a common name for the investigational compound GW501516. It acts as a PPARδ agonist and is not approved for human use. It is prohibited in sport.
It activates PPARδ, a nuclear receptor that influences gene expression related to lipid and energy metabolism. Animal studies show changes in endurance and lipid levels. Human effects and risks are not well established.
No, cardarine is not a steroid. It belongs to a different chemical class, the PPARδ agonists. It is also not a selective androgen receptor modulator.
No. Cardarine has not received approval for human therapeutic use in major jurisdictions. It remains an investigational compound.