The short version of Preclinical research fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-03-27. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
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.
| 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 |
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.
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.
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.
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.
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.
PPARδ is a nuclear receptor that regulates gene expression related to fatty acid oxidation, glucose homeostasis, and mitochondrial function. GW501516 binds to this receptor with high affinity and activates downstream signaling in skeletal muscle and other tissues. Animal studies reported increased endurance and altered fuel preference, but human data remain limited and inconsistent. The precise relationship between receptor activation and observed physiological changes is still an area of active investigation. Researchers have also examined whether the compound affects inflammation or cell proliferation. No approved therapeutic indication exists for cardarine.
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.
== January 18, 1982 (Monday) == A simultaneous crash of four T-38 jets killed the four pilots for the Thunderbirds stunt flying team of the U.S. Air Force, as they were flying in formation at Indian Springs Air Force Auxiliary Field in Nevada in preparation of a flying show set for March. U.S. Army Lieutenant Colonel Charles R. Ray, an assistant military attache in France, was shot and killed, in front of his home in Paris as he was leaving his apartment to drive to his job at the U.S. Embassy. Georges Ibrahim Abdallah, a terrorist from Lebanon who had founded the Lebanese Armed Revolutionary Factions, would be arrested almost three years later in Lyon, convicted of complicity in the murder of Lt. Col. Ray and of the March 31 killing of Israeli diplomat Yacov Barsimantov, and would serve 41 years of a life sentence before being released in 2025. Born: Joanna Newsom, American folk singer; in Grass Valley, California Phạm Phương Thảo, Vietnamese folk singer; in Nghi Lộc district, Nghệ An province Died: Juan O'Gorman, 76, Mexican artist and architect, was found dead from an apparent suicide. Frank C. Baxter, 85, American literature professor and television host of the CBS series Shakespeare on TV and the ABC series Telephone Time, winner of seven Emmy Awards, including Outstanding Male Performer (1954), and 1960 for Outstanding Male Personality (1960). Josef Mai, 94, German fighter ace with 30 victories in World War One; Trent Lehman, 20, former American child actor known for Nanny and the Professor, hanged himself.
== Background == According to Paton, the song is inspired by the sunrise on Blackford Hill in Edinburgh. In a 2012 interview with Hotdisc Television, Paton also stated that at the time, his wife said she had "never seen a daybreak", which also inspired the song.
The King's College Criteria or the King's College Hospital criteria were devised in 1989 to determine if there were any early indices of poor prognosis in patients with acute liver failure. Acute liver failure is defined as the onset of encephalopathy (altered mental status) or coagulopathy (altered bleeding tendencies) within 26 weeks of a patient diagnosed with liver disease. Patients with hepatitis B acquired at birth, Wilson's disease and autoimmune hepatitis are included if their disease was identified within the past 26 weeks. These patients are very ill, and have a very high risk of dying of their illness without adequate treatment which may include liver transplantation. It is important that physicians find ways of identifying patients with acute liver failure early in their course who will do poorly, and may require liver transplantation. The King's College Criteria have consistently shown excellent operating characteristics for determining prognosis in these patients. As liver transplantation becomes a more accessible option for patients with acute liver failure, the King's College Criteria serve a role in determining which patients may require transplantation.
=== Riboswitches === Riboswitches are a type of mRNA structure that help regulate gene expression and often bind a diverse set of ligands. Riboswitches determine how gene expression responds to varying concentrations of small molecules in the cell This motif has been observed in flavin mononucleotide (FMN), cyclic di-AMP (c-di-AMP), and glycine. Riboswitches are said to show pseudoquaternary structure. Several structurally similar regions of a single RNA molecule fold together symmetrically. Because this structure arises from a single molecule and not from multiple separate molecules, it cannot be referred to as true quaternary structure. Depending on where a riboswitch binds and how it is arranged, it can suppress or allow a gene to be expressed Symmetry is an important part of biomolecular three-dimensional configurations. Many proteins are symmetrical on the level of quaternary structure, but RNAs rarely have symmetrical quaternary structures. Even though tertiary structure is variant and essential for all types of RNAs, RNA oligimerization is relatively rare.
Sources: en.wikipedia.org
== External links == Cut-Flower Care — How to Make Your Fresh-Cut Flowers Last by Rose G. Edinger, Brooklyn Botanical Garden, Spring 2003, retrieved October 21, 2006 — What are preserved flowers? Everything you want to know about preserved flowers Archived 2021-01-28 at the Wayback Machine by Floralonly, Albert, published 28, May 2020
=== Proteomics === ETD is widely used in the analysis of protein and large peptides. Important post translational modifications including phosphorylation, glycosylation and disulfide linkages are all analyzed using ETD.
== Function == S100B is glial-specific and is expressed primarily by astrocytes, but not all astrocytes express S100B. It has been shown that S100B is only expressed by a subtype of mature astrocytes that ensheath blood vessels and by NG2-expressing cells. This protein may function in neurite extension, proliferation of melanoma cells, stimulation of Ca2+ fluxes, inhibition of PKC-mediated phosphorylation, astrocytosis and axonal proliferation, and inhibition of microtubule assembly. In the developing CNS it acts as a neurotrophic factor and neuronal survival protein. In the adult organism it is usually elevated due to nervous system damage, which makes it a potential clinical marker.
Sources: en.wikipedia.org
==== Activity-based Profiling ==== To achieve functional degradomics, the enzymatic activity of proteases must be analyzed. Methods have been developed to distinguish the proteolytic activity of different enzymes in biological samples and separate active proteases from their inactive forms, namely zymogen precursors and those proteases bound by inhibitors. Two techniques are activity-based probes (ABPs) and Proteolytic Signature Peptides (PSPs). ABP molecules serve as probes to irreversibly bind only to active proteases and ignore their zymogen precursors and inhibited proteases. Placing a reactive group and a recognizable tag feature on the same molecule using a linker moiety gives an ABP molecule its structure. The reactive molecule, designed after protease inhibitor mechanisms, lends ABPs their specificity towards targeting active proteases. Once bound, the reactive group acts much like an irreversible inhibitor to the protease. Depending on the nature of the tag moiety, the ABP-protease complex can then be visualized or retrieved from biological samples for further studies of localization and quantification. Limitations including difficult production, specificity, stability, and toxicity hamper ABP development but these probes have proved useful in revealing protease biological activity and remain a promising avenue in degradomic technology. PSPs do not depend on targeting active proteases with tagged compounds but rather on quantitative proteomics using stable isotope labeled standard peptides.
=== Setup of experiments === Cold fusion setups utilize an input power source (to ostensibly provide activation energy), a platinum group electrode, a deuterium or hydrogen source, a calorimeter, and, at times, detectors to look for byproducts such as helium or neutrons. Critics have variously taken issue with each of these aspects and have asserted that there has not yet been a consistent reproduction of claimed cold fusion results in either energy output or byproducts. Some cold fusion researchers who claim that they can consistently measure an excess heat effect have argued that the apparent lack of reproducibility might be attributable to a lack of quality control in the electrode metal or the amount of hydrogen or deuterium loaded in the system. Critics have further taken issue with what they describe as mistakes or errors of interpretation that cold fusion researchers have made in calorimetry analyses and energy budgets.
The People's Liberation Army's rations are of two types: Instant Meal Individual (three-item menu) and Self-Heating Individual (twelve-item menu) (Type 13 and 09). Sets of rations issued since 2018 consist of pre-packaged single-person meals sealed in hard plastic retort pouches. A typical Chinese breakfast ration contains roughly 1,000 kcal (4,200 kJ) and includes a compressed food packet, an energy bar, an egg roll with pork, pickled mustard tuber, and a powdered beverage pack. Each Self-Heating Individual comes with an insulated flameless heater that is activated by water.
Diverse perspectives on well-being are found in religious and other traditional belief systems, where well-being often serves as a goal of spiritual practice. In various traditional forms of Hinduism, the highest kind of well-being is not determined by objective external conditions. Instead, it depends primarily on experiential knowledge of the self, brought about through practices like self-inquiry and meditation. Buddhism identifies suffering as a central aspect of all existence. It aims to produce well-being by eliminating the causes of suffering, such as desire and ignorance, achieved through the practice of Buddhist virtues, like compassion, loving-kindness, and equanimity. From the perspective of Confucianism, well-being consists in virtuous activity as a process leading to sagehood and is associated with harmonious relationships and social responsibility. According to Taoism, a life high in well-being is characterized by effortless action that is in harmony with the Tao—the natural way of the universe—and guided by spontaneous dispositions. The Christian tradition holds that the personal connection to God is a central factor of well-being, which may manifest in virtuous activity or contemplation of God. According to the teachings of Islam, well-being is achieved by dedicating one's life as much as possible to worshiping Allah and fulfilling His will, as expressed in the Quran. Well-being is also a topic in various biological sciences with a focus on physiological factors. Research from twin studies suggests that genetic composition is an impactful determinant.
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.
No. Major drug regulators have not approved GW501516 for treating any medical condition. Products sold as cardarine are typically unapproved research chemicals or supplements, so their contents and safety are not assured.