LC-MS/MS raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-02-05 and is reviewed periodically as new material appears.
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.
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.
In laboratory settings, cardarine is studied as a tool compound for probing PPARδ biology. Published experiments often use cell cultures, rodent models, or isolated tissues. Some investigations focus on metabolic effects, while others assess potential risks such as carcinogenicity observed in long-term animal studies. Because human trials are sparse, most knowledge comes from preclinical work and adverse event reports. Scientific literature frequently notes the gap between animal findings and human outcomes. The compound is not a dietary supplement and is not intended for human consumption.
Cardarine is a common name for GW501516, a synthetic compound developed in the 1990s through research collaborations involving GlaxoSmithKline. It belongs to a class of molecules known as peroxisome proliferator-activated receptor delta agonists. Early studies explored its effects on lipid metabolism and energy expenditure in animal models. The compound was never approved as a human medicine, and clinical development was discontinued. In the years since, it has appeared in fitness and bodybuilding communities as a performance-enhancing substance. Regulatory agencies classify it as an unapproved drug.
| 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. |
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.
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.
Cardarine is explicitly prohibited by the World Anti-Doping Agency under the class of PPARδ agonists. Its presence in urine or blood samples can be detected using mass spectrometry-based methods, often liquid chromatography-tandem mass spectrometry. Athletes who test positive may face sanctions, including bans from competition. The compound is also regulated as a prescription-only or unapproved drug in many countries. Enforcement varies by jurisdiction, and some regions treat it as a controlled substance. Online sales may occur despite these restrictions, creating quality and legal risks.
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.
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.
=== Quality === In the context of a clinical trial, quality typically refers to the absence of errors which can impact decision making, both during the conduct of the trial and in use of the trial results.
== History == BioDuro was founded in 1996 in the United States as a drug discovery services company. In 2009, it was acquired by Pharmaceutical Product Development (PPD), a leading global contract research organization. In 2020, Advent International merged BioDuro with the China-based CRO Sundia to form BioDuro-Sundia, creating a combined CRDMO serving biotech and pharma clients globally. In 2021, the company expanded its U.S. operations in Irvine to support clinical and commercial drug product manufacturing. In 2025, BioDuro announced new investments in China, including a Bengbu process development and scale-up site and an OEB-5 high-potency laboratory for ADC payloads and HPAPIs.
A highly abundant weed species in Papaver somniferum fields was shown to be Papaver rhoeas. Papaver somniferum and Papaver rhoeas are congeners and belong to the same plant family, which impedes the chemical control of this weed species. Therefore, weed management represents a big challenge and requires technological knowledge from the farmer. In order to increase the efficiency of weed control not only chemical weed control should be applied but also mechanical weed control. For P. somniferum, a growth density of 70 to 80 plants per square metre is recommended. Latex-to-biomass yield is greatest under conditions of slight water deficit.
== External links == "Lurbinectedin". NCI Dictionary of Cancer Terms. National Cancer Institute. Clinical trial number NCT02454972 for "Clinical Trial of Lurbinectedin (PM01183) in Selected Advanced Solid Tumors" at ClinicalTrials.gov
==== Insects ==== Serotonin is evolutionarily conserved and appears across the animal kingdom. It is seen in insect processes in roles similar to in the human central nervous system, such as memory, appetite, sleep, and behavior. Some circuits in mushroom bodies are serotonergic. (See specific Drosophila example below, §Dipterans.)
Sources: en.wikipedia.org
== Factor structure == Although Cohen et al. (1983) originally argued the PSS to be a unidimensional measure of perceived stress, the research community generally views the 14- and 10-item forms as two dimensional. The predominant forms consist of positively and negatively phrased items. Under exploratory factor analysis the negatively phrased items have been found to load onto a second factor separate from the positively phrased items, giving the appearance of a method effect. That is, a significant portion of the variability in the responses to a subset of the items is a product of how the items are phrased. However, inspection of the items suggests a substantive difference in the positively phrased items versus the negatively phrased items with the negatively phrased items on their face characterizing perceived helplessness while the positively phrased items may be characterizing perceived self-efficacy. Some support for this conceptualization has emerged. For example, Hewitt et al. (1992) found that the perceived helplessness items tended to predict depression in both men and women while the positively phrased items tended to predict depression in women only. The pattern of differential prediction of depression between genders tends to indicate the negatively phrased items are tapping something substantive rather than a method effect.
Adenine forms adenosine, a nucleoside, when attached to ribose, and deoxyadenosine when attached to deoxyribose. It forms adenosine triphosphate (ATP), a nucleoside triphosphate, when three phosphate groups are added to adenosine. Adenosine triphosphate is used in cellular metabolism as one of the basic methods of transferring chemical energy between chemical reactions. ATP is thus a derivative of adenine, adenosine, cyclic adenosine monophosphate, and adenosine diphosphate.
Somali architecture is a rich and diverse tradition of engineering and design. Spanning the country's ancient, medieval and early modern periods, it also embraces the fusion of Somalo-Islamic architecture with contemporary Western designs. In ancient Somalia, pyramidical structures known in Somali as taalo were a popular burial style, with hundreds of these dry stone monuments scattered around the country today. Houses were built of dressed stone similar to the ones in ancient Egypt. There are also examples of courtyards and large stone walls enclosing settlements, such as the Wargaade Wall. The adoption of Islam in Somalia's early medieval history brought Islamic architectural influences from Arabia and Persia. This stimulated a shift in construction from dry stone and other related materials to coral stone, sun dried bricks, and the widespread use of limestone in Somali architecture. Many of the new architectural designs, such as mosques, were built on the ruins of older structures, a practice that would continue throughout the following centuries.
== Channel mix == In practice, many organizations use a mix of different channels; a direct sales force may call on larger customers. This may be complemented with other agents to cover smaller customers and prospects. When a single organization uses a variety of different channels to reach its markets, this is known as a multi-channel distribution network. In addition, online retailing or e-commerce is leading to disintermediation, the removal of intermediaries from a supply chain. Retailing via smartphone or m-commerce is also a growth area.
He sailed for New York on the RMS Caronia on 19 September 1925, intending to study under Robert Chambers at Cornell University Medical College, but the micromanipulator he required for his research on the blood vessels of the brain was not available, so he arranged to work at the laboratory of Alfred Newton Richards at the University of Pennsylvania. He finally joined Chambers in March 1926. He hoped to be able to return to the UK via Australia and marry Ethel Reed in Adelaide, but in November 1925 he accepted an offer of a research position at London Hospital. The position came with five years' tenure and a salary of £850 per annum (equivalent to £45,000 in 2025), but they wanted him to start immediately. Florey managed to negotiate a delay, but only until May 1926. He returned to the UK on 13 May. Ethel joined him there in September, and they were married at Holy Trinity, Paddington, on 19 October.
Sources: en.wikipedia.org
Isotope masses from: Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001 Half-life, spin, and isomer data selected from the following sources. Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001 National Nuclear Data Center. "NuDat 3.0 database". Brookhaven National Laboratory. Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.
=== In diagnosis === Lactoferrin levels in tear fluid have been shown to decrease in dry eye diseases such as Sjögren's syndrome. A rapid, portable test utilizing microfluidic technology has been developed to enable measurement of lactoferrin levels in human tear fluid at the point-of-care with the aim of improving diagnosis of Sjögren's syndrome and other forms of dry eye disease.
This could provide a pathway from fatty acids to glucose, but whether this actually happens in the human body is controversial. Although most gluconeogenesis occurs in the liver, the relative contribution of gluconeogenesis by the kidney is increased in diabetes and prolonged fasting. The gluconeogenesis pathway is highly endergonic until it is coupled to the hydrolysis of ATP or GTP, effectively making the process exergonic. For example, the pathway leading from pyruvate to glucose-6-phosphate requires 4 molecules of ATP and 2 molecules of GTP to proceed spontaneously. These ATPs are supplied from fatty acid catabolism via beta oxidation.
== Synthesis == The compound was first described in 1935 by Ferdinand Münz, who prepared the compound from ethylenediamine and chloroacetic acid. Today, EDTA is mainly synthesised from ethylenediamine (1,2-diaminoethane), formaldehyde, and sodium cyanide. This route yields the tetrasodium EDTA, which is converted in a subsequent step into the acid forms:
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.
Cardarine is a common name for GW501516, a synthetic PPARδ agonist developed for research. It has not been approved as a medication in any country. It is classified as an unapproved drug and a prohibited substance in sport.