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 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
Cardarine is a common name for GW501516, also GW-1516, a synthetic compound developed as a peroxisome proliferator-activated receptor delta (PPARδ) agonist. It belongs to a class of agents that modulate gene transcription related to lipid and energy metabolism. The compound was studied in preclinical and early clinical research for metabolic and cardiovascular conditions, but it did not progress to approved therapeutic use. Its name appears in fitness and sports contexts despite not being approved as a drug.
PPARδ is a nuclear receptor that influences transcription of genes involved in fatty acid oxidation, lipid transport, and energy homeostasis. GW501516 binds and activates this receptor with high selectivity relative to PPARα and PPARγ in laboratory assays. Activation alters expression of target genes in skeletal muscle, liver, and adipose tissue in animal models. The exact clinical consequences of these changes in humans remain incompletely characterized, and observed effects in animals do not establish therapeutic benefit or safety.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | PPARδ agonist | Not an anabolic steroid. |
| Common synonyms | GW501516, GW-1516 | Cardarine is an informal name. |
| Appearance | White to off-white powder | Typical for research-grade solid. |
| Solubility class | Poorly soluble in water; soluble in some organic solvents | Such as DMSO or ethanol in laboratory settings. |
| Typical storage temperature | Cool, dry, protected from light | Specific conditions vary by supplier and form. |
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.
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.
Literature on cardarine often separates receptor pharmacology from toxicology. Mechanistic papers describe PPARδ activation and gene expression changes, while safety assessments focus on carcinogenicity and species differences. Questions remain about whether rodent tumors arise through PPARδ-dependent or off-target mechanisms. Another open area is how human metabolism and exposure compare with those in animal studies. Analytical methods such as liquid chromatography–mass spectrometry are used to confirm identity in biological and product samples.
Cardarine has no approved therapeutic indication and is not marketed as a medicine. The World Anti-Doping Agency lists GW501516 as a prohibited substance at all times, covering both in-competition and out-of-competition periods. National laws vary: some countries treat it as an unapproved drug subject to import controls, while others have specific restrictions on sale for human consumption. It is often sold as a research chemical, a label that does not imply safety or legality. Enforcement actions have targeted online vendors and shipments.
Anti-doping laboratories identify GW501516 and related metabolites using liquid chromatography coupled with tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be analyzed. The method targets the parent compound and phase I and phase II metabolites, which extend the detection window. Because the substance is prohibited at all times, athletes can be tested outside competition. Detection limits and windows depend on the assay, sample type, and individual metabolism.
Cardarine is frequently described as a fat-burning or endurance-enhancing supplement, but these claims exceed the available evidence. The compound is not a hormone, steroid, or selective androgen receptor modulator. Research articles discuss it as a tool compound for studying PPARδ biology, while anti-doping literature focuses on its abuse and detection. Quality of unapproved products is uncertain, and independent analyses have found impurities or incorrect labeling. Open questions include whether human cancer risk resembles that seen in rodents and how often non-athletes use the substance.
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 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.
=== In mines === 222Rn decay products have been classified by the International Agency for Research on Cancer as being carcinogenic to humans, and as a gas that can be inhaled, lung cancer is a particular concern for people exposed to elevated levels of radon for sustained periods. During the 1940s and 1950s, when safety standards requiring expensive ventilation in mines were not widely implemented, radon exposure was linked to lung cancer among non-smoking miners of uranium and other hard rock materials in what is now the Czech Republic, and later among miners from the Southwestern US and South Australia. Despite these hazards being known in the early 1950s, this occupational hazard remained poorly managed in many mines until the 1970s. During this period, several entrepreneurs opened former uranium mines in the US to the general public and advertised alleged health benefits from breathing radon gas underground. Health benefits claimed included relief from pain, sinus problems, asthma, and arthritis, but the government banned such advertisements in 1975, and subsequent works have debated the truth of such claimed health effects, citing the documented ill effects of radiation on the body. Since that time, ventilation and other measures have been used to reduce radon levels in most affected mines that continue to operate. In recent years, the average annual exposure of uranium miners has fallen to levels similar to the concentrations inhaled in some homes.
, which may allow to redefine the distributions as simple functions of the age only. If the flow is steady (but a generalization to non-steady flow is possible) and is conservative, then the exit age distribution and the internal age distribution can be related one to the other:
ADP-ribosylation is the addition of one or more ADP-ribose moieties to a protein. It is a reversible post-translational modification that is involved in many cellular processes, including cell signaling, DNA repair, gene regulation and apoptosis. Improper ADP-ribosylation has been implicated in some forms of cancer. It is also the basis for the toxicity of bacterial compounds such as cholera toxin, diphtheria toxin, and others.
Sources: en.wikipedia.org
A detailed report of the diagnosis, treatment, and follow-up of an individual patient. Case reports also contain some demographic information about the patient (for example, age, gender, ethnic origin). (NCI) Case report form
=== Marriages and children === Galloway has been married four times and has six children. In 1979, he married Elaine Fyffe, with whom he has a daughter. The couple separated in 1987 and divorced in 1999. In 1994, Galloway married Amineh Abu-Zayyad, a Palestinian biologist, in a non-legally binding Islamic ceremony; a legally binding civil ceremony followed in March 2000. Abu-Zayyad was granted a divorce in February 2009, after an estrangement of several years, on the grounds of "unreasonable behaviour"; her petition was not contested. Galloway married Rima Husseini, his former researcher, in a non-legally binding Islamic ceremony in 2005. Galloway had two sons with Husseini, who is from Lebanon. On 31 March 2012 he married his fourth wife, the Dutch–Indonesian anthropologist Putri Gayatri Pertiwi, then 27, in Amsterdam. The initial event was followed by a traditional Javanese wedding ceremony in Sumatra and a civil marriage at the House of Commons in September 2012. Pertiwi worked as a consultant for a Dutch research firm and as a co-presenter of Galloway's TV show Sputnik. The couple have three children.
==== Allosteric regulator ==== Acetyl-CoA serves as an allosteric regulator of pyruvate dehydrogenase kinase (PDK). It regulates through the ratio of acetyl-CoA versus CoA. Increased concentration of acetyl-CoA activates PDK. Acetyl-CoA is also an allosteric activator of pyruvate carboxylase.
Sources: en.wikipedia.org
Meanwhile, General Armada, another of the conspirators, tried to get the king to authorize him to appear on his behalf in the Congress of Deputies, but Juan Carlos I refused. In spite of this, Armada went to the Congress where he met with Tejero, to whom he explained his plan to form a concentration government presided by him and asked him to let him address the deputies. Tejero flatly refused because he wanted a purely military government. At one o'clock in the morning, the king, dressed as Captain General as supreme chief of the Armed Forces, addressed the country condemning the military coup and defending the democratic system. It was "the decisive moment to defeat the coup". Two hours later, Milans del Bosch ordered the withdrawal of his troops and the next morning Tejero surrendered, releasing the government and the deputies. The coup of "23-F" had failed. Shortly after, demonstrations in support of the Constitution and in defense of democracy were called, which were the largest of those held up to that time.
=== Non-physician use === In the United States, it has become more common for non-physician roles to wear white coats in clinical settings, with positions such as mid-level practitioners, nurse administrators, clinical social workers, and other healthcare fields donning the coats. Some nursing schools even provide white coat ceremonies to new nursing students.
== Use in antibody-drug conjugates == A new antibody-drug conjugate (ADC) technology based on α-amanitin has shown activity in therapy-resistant tumor cells, e.g. cells expressing multi-drug resistant transporters, tumor-initiating cells and non-dividing cells at picomolar concentrations. The unique mode of action of α-amanitin seems to make the amanitin-based ADCs a suitable toxic payload. This toxin has a water-soluble structure, resulting in ADCs with low tendency for aggregation. Significant clinical advances occurred in 2025 and 2026 with Heidelberg Pharma’s lead candidate HDP-101 (pamlectabart tismanitin), a BCMA-targeted amanitin-based antibody-drug conjugate (ATAC) for relapsed or refractory multiple myeloma. In the ongoing Phase I/IIa trial (NCT04879043), dose escalation proceeded safely up to 218 µg/kg without reaching a maximum tolerated dose, and the recommended Phase IIa dose was selected in April 2026. The program received FDA Fast Track designation in October 2025. In the higher-dose cohorts (90–140 µg/kg), overall response rates reached 38–57 %, with several heavily pretreated patients, including those who had failed prior BCMA-directed therapies, achieving stringent complete remissions lasting more than one year. The safety profile remained favorable, with mostly mild-to-moderate and manageable adverse events and no clinically relevant hepatotoxicity, ocular toxicity, or renal impairment.
== Causes == Prolidase deficiency is the result of mutations on the PEPD gene which is located on the "q", i.e., long, arm of chromosome 19 at region 1, band 3, sub-band 11 (notated as 19q13.11). This gene codes for the prolidase Enzyme, also known as peptidase-D. At least 19 different mutations in the PEPD gene have been identified in individuals affected by the disorder.
Sources: en.wikipedia.org
Cardarine is commonly known as GW501516 or GW-1516. These names refer to the same synthetic compound. It is not a brand-name approved medicine.
No, cardarine is not a steroid. It is classified as a PPARδ agonist. Its structure and receptor target differ from anabolic steroids.
No regulatory agency has approved cardarine as a medicine. It was investigated in early research but development was discontinued. It is not available as a prescription drug.
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.