If you have been reading about Nuclear receptor and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-12-24. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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 |
|---|---|---|
| CAS Registry Number | 317318-70-0 | Unique identifier for the compound. |
| Chemical class | PPARδ agonist | Synthetic ligand for peroxisome proliferator-activated receptor delta. |
| Appearance | White to off-white solid | Typical form of research-grade material. |
| Solubility | Soluble in DMSO and ethanol | Poorly soluble in water. |
| Typical storage | -20°C | Recommended for long-term storage of stock solutions. |
Regulatory bodies treat GW501516 as a prohibited substance in competitive sport. The World Anti-Doping Agency added it to the prohibited list, and it falls under classes covering metabolic modulators and hormone-related agents. It is not approved by drug regulators for human use, and it is not a lawful dietary supplement. Products sold under the cardarine name may contain unlisted ingredients or different compounds. Because no approved product exists, quality and identity are not guaranteed by pharmaceutical manufacturing standards.
Cardarine is a common name for the investigational chemical GW501516, also written GW-1516. It was developed as a peroxisome proliferator-activated receptor delta agonist for metabolic conditions such as dyslipidemia. Early research focused on lipid handling and energy use in skeletal muscle and other tissues. The compound was never approved as a medicine. In public discussion, it is often grouped with performance-enhancing substances, although its receptor target differs from that of anabolic steroids or selective androgen receptor modulators. Regulatory and health authorities have issued warnings about its use.
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.
Using these techniques, a model of human metabolism has now been produced, which will guide future drug discovery and biochemical research. These models are now used in network analysis, to classify human diseases into groups that share common proteins or metabolites. Bacterial metabolic networks are a striking example of bow-tie organization, an architecture able to input a wide range of nutrients and produce a large variety of products and complex macromolecules using a relatively few intermediate common currencies. A major technological application of this information is metabolic engineering. Here, organisms such as yeast, plants or bacteria are genetically modified to make them more useful in red biotechnology and aid the production of drugs such as antibiotics or industrial chemicals such as 1,3-propanediol and shikimic acid. These genetic modifications usually aim to reduce the amount of energy used to produce the product, increase yields and reduce the production of wastes.
== History == Emoxypine was first synthesized by L.D. Smirnov and K.M. Dumayev, then studied and developed in the Russian Institute of Pharmacology, Russian Academy of Medical Sciences and Russian Scientific Center of Bioactive Substances Safety. Its research and use has been largely isolated to former Soviet states, with little interest from other countries.
== History == Canakinumab was being developed by Novartis for the treatment of rheumatoid arthritis, but this trial was completed in October 2009. Canakinumab is also in phase I clinical trials as a possible treatment for chronic obstructive pulmonary disease, gout, and coronary artery disease (the CANTOS trial). It is also in trials for schizophrenia. In gout, it may result in better outcomes than a low dose of a steroid, but costs five thousand times more. The U.S. Food and Drug Administration (FDA) approved canakinumab for CAPS in June 2009, followed by the European Medicines Agency (EMA) in October. In August 2017, the results of the CANTOS trial were announced at the European Society of Cardiology. Those treated in CANTOS had a 15% reduction in deaths from heart attacks, stroke and cardiovascular disease combined. However, CANTOS reported serious side-effects and no statistically significant overall survival benefit.
The xanthoproteic reaction (xanthoprotic test) is a method that can be used to detect a presence of protein soluble in a solution, using concentrated nitric acid. The test gives a positive result in amino acids carrying aromatic groups, especially in the presence of tyrosine. If the test is positive the proof is neutralized with an alkali, turning dark yellow. The yellow colour is due to xanthoproteic acid which is formed due to nitration of certain amino acids, most common examples being tyrosine and tryptophan. This chemical reaction is a qualitative test, determining the presence or absence of proteins.
Sources: en.wikipedia.org
== Ecology == Cercopagis pengoi is eurythermal and euryhaline, being able to tolerate a wide range of temperature and salinity. It is a pelagic species, found in a higher abundance further from the shore and from the bottom. It is a generalist feeder which preys on various species in both micro- and mesozooplankton (i.e. cladocerans, copepods, rotifers). The size of prey ranges from its own body size to seventeen times smaller. Prey is captured using thoracopods I, then retained by thoracopods II-IV, and crushed by its cuticle by mandibles, finally C. pengoi sucks the prey body contents. Fishhook waterfleas reproduce asexually during the summer, which produces a quick rise in population. When conditions are inhospitable, C. pengoi will undergo sexual reproduction, producing resting eggs that can over-winter and repopulate the lake quickly in the spring. Resting eggs can withstand desiccation (extreme dryness), freeze-drying, and ingestion by fish.
== Taxonomy == The first scientific description of Vanilla planifolia was published by Henry Charles Andrews in the eighth volume of his The Botanist's Repository. In his description he credits Charles Plumier with publishing a description of it in 1703 as the third species of the genus Vanilla. Andrews created the drawing in his book from a specimen that bloomed in a hothouse belonging to Charles Greville.
=== January 2004 === January 3: Marwan Hassoun and his cousin Zaydun Al-Samarrai are taken from their broken-down truck at about curfew time and forced to jump from the Tharthar dam into the Tigris River; the latter drowns. First Lt. Jack M. Saville and Sgt. 1st Class Tracy E. Perkins were charged on 2004 June 7 with manslaughter, assault, conspiracy, making false statements, and obstruction of justice. Sgt. Reggie Martinez was charged three weeks later with manslaughter and for making false statements, and Spec. Terry Bowman with assault and making false statements. Martinez' and Bowman's charges were dropped; Perkins got six months in jail. Saville was jailed (45 days) and fined $12,000 for assault but he remained on active duty until his military obligation was fulfilled.
=== Presymbiosis === To form an ectomycorrhizal connection, the fungal hyphae must first grow towards the plant's roots. Then they must envelope and penetrate the root cap cells and infect them, allowing the symbiotic Hartig net and associated structures to form. Both partners (plant and fungus) must follow a precise sequence of gene expression for this to be successful. There is evidence that communication between the partners in the early stage of ectomycorrhiza occurs in some cases via volatile organic compounds produced only during the interaction phase, and that genes involved in secretory, apical growth, and infection processes show changes in expression early in the pre-contact phase. Thus, a complex set of molecular changes appears to take place even before the fungus and host plant make contact. The plant hosts release metabolites into the rhizosphere that can trigger basidiospore germination, growth of hyphae towards the root, and the early steps of EcM formation. These include flavonoids, diterpenes, cytokinins, hormones and other nutrients. Some host-released metabolites have been shown to stimulate fungal growth in Pisolithus, modify the branching angle of hyphae, and cause other changes in the fungus. Some fungal genes appear to be expressed before plant contact, suggesting that signals in the soil may induce important fungal genes at a distance from the plant.
=== Lebanon === On 6 November 2023, in response to the killing of four civilians in southern Lebanon, Prime Minister Najib Mikati announced that his government would submit an urgent complaint to the UN Security Council against Israel saying that its "targeting of civilians in its aggression against Lebanon" was a "heinous crime". Samir Geagea, the leader of a main Christian political party, blamed Hezbollah for attacking Israel and said that it harmed Lebanon while having no impact on Israel's Gaza offensive.
Sources: en.wikipedia.org
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.
No. Cardarine is not an anabolic steroid; it belongs to a different chemical class that targets PPARδ. Steroids act primarily through androgen receptors, while cardarine acts through a nuclear receptor involved in metabolism.
Some rodent studies reported increased endurance and changes in fat metabolism after cardarine exposure. Long-term studies in animals also raised concerns about cancer in certain tissues. Human trial data are limited, so these findings cannot be directly translated to people.
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.