Reference standard 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 2025-12-13. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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 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.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | GW501516; GW-1516; endurobol | GW501516 is the research code |
| Drug class | PPARδ agonist | Not a selective androgen receptor modulator |
| Molecular formula | C21H18F3NO3S2 | Established chemical formula |
| Molar mass | 453.5 g/mol | Calculated from the formula |
| Regulatory status | Prohibited in sport; not approved as medicine | Status varies by country |
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.
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.
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.
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.
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.
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.
=== Breastfeeding === In 2016, estimates suggested that more widespread breastfeeding could prevent about 823,000 deaths annually of children under age 5. In addition to reducing infant deaths, breast milk provides an important source of micronutrients - which are clinically proven to bolster children's immune systems – and provides long-term defenses against non-communicable and allergic diseases. Breastfeeding may improve cognitive abilities in children, and correlates strongly with individual educational achievements. As previously noted, lack of proper breastfeeding is a major factor in child mortality rates, and is a primary determinant of disease development for children. The medical community recommends exclusively breastfeeding infants for 6 months, with nutritional whole food supplementation and continued breastfeeding up to 2 years or older for overall optimal health outcomes. Exclusive breastfeeding is defined as giving an infant only breast milk for six months as a source of food and nutrition. This means no other liquids, including water or semi-solid foods.
Under this state, there was great religious freedom, and alongside the Norman nobles existed a meritocratic bureaucracy of Jews, Muslims and Christians, both Catholic and Eastern Orthodox. The Kingdom of Sicily thus became characterized by Norman, Byzantine, Greek, Arab, Lombard and "native" Sicilian populations living in harmony, and its Norman rulers fostered plans of establishing an empire that would have encompassed Fatimid Egypt as well as the crusader states in the Levant. One of the great geographical treatises of the Middle Ages, the "Tabula Rogeriana", was written by al-Idrisi for King Roger II of Sicily, and entitled "Kitab Rudjdjar" ("The Book of Roger").
=== Physical properties === Elemental magnesium is a gray-white lightweight metal, two-thirds the density of aluminium. Magnesium has the lowest melting (923 K (650 °C)) and the lowest boiling point (1,363 K (1,090 °C)) of all the alkaline earth metals. Pure polycrystalline magnesium is brittle and easily fractures along shear bands. It becomes much more malleable when alloyed with small amounts of other metals, such as 1% aluminium. The malleability of polycrystalline magnesium can also be significantly improved by reducing its grain size to about 1 μm or less.
Sources: en.wikipedia.org
In 1928 he obtained a Rockefeller Travelling Fellowship to visit Europe, where he worked for a while in the Anatomical School at Cambridge University, England, then headed by Professor Wilson, and in the Anatomical School at Utrecht University, the Netherlands, then headed by Professor Boecke. Also in 1928, Oscar Tiegs was awarded the David Syme Research Prize. As a histologist Oscar Tiegs developed an interest in Boecke's suggestion of a double innervation of vertebrate skeletal muscle. From this interest he undertook a physiological investigation of the sympathetic system in the muscle, finding no such action except in blood vessels, all muscular action seemingly being caused by an adrenaline-like substance. Oscar Tiegs in this work corrected errors and ambiguities in the work of others, and showed the validity of some traditional interpretations.
=== Millennium Cybernetics === In 1994, Ayyadurai founded a company called Millennium Cybernetics, which produces email management software originally called Xiva and now called EchoMail. The software analyzes incoming email messages to organizations before either replying automatically or forwarding it to the most relevant department. By 2001, customers included Kmart, American Express, and Calvin Klein, as well as more than thirty U.S. senators to help handle constituent email. EchoMail competed with more established customer relationship management software that had an email component.
== History == Robert Vince and Susan Daluge along with Mei Hua, a visiting scientist from China, developed the medication in the '80s. Abacavir was approved by the US Food and Drug Administration (FDA) in December 1998 and is the fifteenth approved antiretroviral drug in the United States.
== Organization == The LLNL director is supported by a senior executive team consisting of the deputy director, the deputy director for science and technology, principal associate directors, and other senior executives who manage areas/functions directly reporting to the laboratory director. The director's office is organized into these functional areas/offices:
Sources: en.wikipedia.org
No. Cardarine is GW501516, a PPARδ agonist, while SARMs act on androgen receptors. The two classes are often grouped in informal discussions despite different mechanisms.
No. It has no approved medical indication in any country. Regulatory agencies have not cleared it for treatment or prevention of any condition.
Early clinical work stopped after rodent carcinogenicity findings. Those animal results raised concerns about long-term human risk, although direct human evidence is lacking. The human relevance of the tumors remains an open scientific question.
Yes, WADA prohibits cardarine as a PPARδ agonist. It appears on the prohibited list and can be detected in urine or blood. Athletes using it risk sanctions.