A practical reference on Preclinical research: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-10-15. 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.
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.
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 |
|---|---|---|
| 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 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.
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.
Published studies have examined GW501516 in animal models of obesity, insulin resistance, and exercise endurance. Early human trials reportedly ended, and development was discontinued after preclinical findings raised concerns about cancer in some rodent studies. Regulatory agencies have not approved cardarine for any medical use. Its availability through non-pharmaceutical channels raises questions about identity, purity, and legal status that are separate from its laboratory pharmacology. Those questions are often addressed through analytical testing rather than assumptions about product labels.
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.
During the Revolutions of 1848, the Austrian Chancellor Prince Klemens von Metternich resigned (March–April 1848). The young archduke was widely expected to soon succeed his uncle on the throne. While he was appointed Governor of Bohemia on 6 April 1848, he never took up the post. Sent instead to the front in Italy, he joined Field Marshal Radetzky on campaign on 29 April, receiving his baptism of fire on 5 May at Santa Lucia. By all accounts, he handled his first military experience calmly and with dignity. Around the same time, the imperial family fled revolutionary Vienna for the calmer setting of Innsbruck, in Tyrol. Called back from Italy, the archduke joined the rest of his family at Innsbruck by mid-June. It was here that Franz Joseph first met his cousin and future bride, Elisabeth, then a girl of 10, but apparently this meeting made little impression. Following Austria's victory over the Italians at Custoza in late July 1848, the court felt it safe to return to Vienna, and Franz Joseph travelled with them. But within a few weeks, Vienna again appeared unsafe, and in September, the court left once more, this time for Olmütz in Moravia. By now, Alfred I, Prince of Windisch-Grätz, an influential military commander in Bohemia, was determined to see the young archduke soon put on the throne. It was thought that a new ruler would not be bound by the oaths to respect constitutional government to which Ferdinand had been forced to agree, and that it was necessary to find a young, energetic emperor to replace the kindly but mentally unfit Ferdinand.
==== Belief systems ==== Several different and sometimes conflicting belief systems emerged regarding acupuncture. This may have been the result of competing schools of thought. Some ancient texts referred to using acupuncture to cause bleeding, while others mixed the ideas of blood-letting and spiritual qi energy. Over time, the focus shifted from blood to the concept of puncturing specific points on the body, and eventually to balancing Yin and Yang energies as well. According to David Ramey, no single "method or theory" was ever predominantly adopted as the standard. At the time, scientific knowledge of medicine was not yet developed, especially because in China dissection of the deceased was forbidden, preventing the development of basic anatomical knowledge. It is not certain when specific acupuncture points were introduced, but the autobiography of Bian Que from around 400–500 BC references inserting needles at designated areas. Bian Que believed there was a single acupuncture point at the top of one's skull that he called the point "of the hundred meetings." Texts dated to be from 156 to 186 BC document early beliefs in channels of life force energy called meridians that would later be an element in early acupuncture beliefs. Ramey and Buell said the "practice and theoretical underpinnings" of modern acupuncture were introduced in The Yellow Emperor's Classic (Huangdi Neijing) around 100 BC. It introduced the concept of using acupuncture to manipulate the flow of life energy (qi) in a network of meridian (channels) in the body.
Plastic Pasteur pipettes, also referred to as transfer pipettes, have their stems and bulbs in the form of a single piece made of soft plastic such as polyethylene. The bulb portion is thinner and therefore "squeezable", while the pipette portion is thick enough to be rigid. They commonly come in 1, 2, 3, and 5 ml which comes with a specific drop size of 10, 20, 25, 35, and 50 μL. The volumes are usually marked on the stem, though the markings are rather crude and are not particularly accurate. A plastic dropper is relatively inexpensive and disposable, so they are often used to avoid cross-contamination. In a solution containing cells or protein, it reduces the loss of cell or protein that binds to glass. Some plastic pipettes include a long flexible tube that can be bent for drawing solution from small volume tubes. Plastic Pasteur pipettes are often used in biology where most media are aqueous and solvent resistance is not important. (Most organic solvents, such as hexane and acetone cannot be used in plastic Pasteur pipettes as the solvent can dissolve the plastic.) The pipettes are also hard to wash and are usually discarded with other biohazard waste after one use. Plastic bulb pipettes are generally not precise enough to be used for exact measurements, whereas their glass counterparts can be extremely precise.
Although a further tiny energy gain could be extracted by synthesizing 62Ni, which has a marginally higher binding energy than 56Fe, conditions in stars are unsuitable for this process. Element production in supernovas greatly favor iron over nickel, and in any case, 56Fe still has a lower mass per nucleon than 62Ni due to its higher fraction of lighter protons. Hence, elements heavier than iron require a supernova for their formation, involving rapid neutron capture by starting 56Fe nuclei. In the far future of the universe, assuming that proton decay does not occur, cold fusion occurring via quantum tunnelling would cause the light nuclei in ordinary matter to fuse into 56Fe nuclei. Fission and alpha-particle emission would then make heavy nuclei decay into iron, converting all stellar-mass objects to cold spheres of pure iron.
Sources: en.wikipedia.org
== External links == Parathyroid+Hormone+Receptors at the U.S. National Library of Medicine Medical Subject Headings (MeSH) "Parathyroid Hormone Receptors". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology.
==== Cardiovascular tissues ==== Cardiovascular regenerative medicine focuses on repairing damaged myocardial tissue, heart valves, and peripheral blood vessels, primarily targeting ischemic heart disease and congenital heart defects. Because adult mammalian cardiomyocytes possess highly restricted proliferative capacity, therapeutic strategies utilize engineered cardiac patches, cell-seeded hydrogels, and decellularized extracellular matrix (ECM) components to stimulate localized myocardial repair after a myocardial infarction. Clinical and pre-clinical research focuses heavily on using induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and vascular endothelial cells embedded within porous, biomimetic polymeric scaffolds to ensure functional electrical coupling and host tissue integration. Additionally, tissue-engineered vascular grafts (TEVGs) are investigated as synthetic or bio-resorbable alternatives for coronary artery bypass surgery, where scaffold porosity is precisely tuned to allow host cell infiltration, smooth muscle cell remodeling, and functional neovascularization without inducing thrombosis.
However, there have also been pleas to take a more nuanced approach to judging the distribution skewness of the impact factor. Ludo Waltman and Vincent Antonio Traag, in their 2021 paper, ran numerous simulations and concluded that "statistical objections against the use of the IF at the level of individual articles are not convincing", and that "the IF may be a more accurate indicator of the value of an article than the number of citations of the article".
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.
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.