Everything below concerns Nuclear receptor. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-04-10. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
The pharmacological interest in cardarine centers on PPARδ activation and its downstream effects on lipid handling and mitochondrial function. In animal studies, PPARδ agonists have been associated with changes in exercise endurance and fatty acid utilization, though results vary by model and protocol. Human data remain sparse, and the absence of large controlled trials limits conclusions about efficacy. Researchers often describe the compound as a tool for probing PPARδ biology rather than a proven therapeutic agent.
Safety discussions about cardarine frequently cite rodent carcinogenicity findings reported in the 2000s. In those studies, treated animals developed tumors at multiple sites, leading sponsors to discontinue clinical development. The relevance of these findings to humans has not been resolved, but they are a major reason the compound is not approved. Current literature emphasizes uncertainty about long-term effects and the risks of unregulated use. Regulators and health agencies have not established a safe human exposure level.
| 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. |
Anti-doping laboratories identify GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the usual matrix, and detection can occur after the parent compound has cleared from blood. The exact detection window depends on dose, formulation, individual metabolism, and assay sensitivity. Because the compound is prohibited at all times, athletes are subject to testing in and out of competition. Analytical methods continue to improve as new metabolites and designer analogs are characterized.
GW501516 acts as a ligand for PPAR delta, a nuclear receptor that regulates transcription of genes involved in fatty acid oxidation and energy use. Activation of this receptor in skeletal muscle shifts metabolism toward fat burning in animal models. The compound does not burn fat directly; it changes gene expression over hours to days. Researchers study it to understand metabolic flexibility and exercise adaptation. Effects observed in rodents are not automatically expected in humans.
Preclinical research reported that GW501516 increased running endurance in mice and improved lipid profiles in some animal species. Early human trials explored effects on high-density lipoprotein cholesterol, triglycerides, and glucose handling, but the program was discontinued. Published human data are sparse and do not establish efficacy for any condition. Studies also examined PPAR delta in cancer biology, with conflicting findings across models. The relationship between receptor activation, tissue context, and disease risk remains an active area of investigation.
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.
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.
The Don Cossacks were revived in the early 1990s and were officially recognised by the Russian Government in 1997, its Ataman holding the rank, insignia and uniform of a full Marshal. In 1992 they joined the separatist forces during the Transnistria War. Don Cossacks volunteered by hundreds to fight in South Ossetia during the 2008 Russo-Georgian war. In 2009, the Ukrainian Security Service banned a leader of the Don Cossacks from entering Ukraine in order to prevent the creation of an illegal parliamentary formation on Ukrainian territory. Since 2014, members of Don Cossacks have participated in the war in Eastern Ukraine as independent volunteers for the pro-Russian Donbass militias. Reportedly several military formations were formed though most of these groups were subsequently disbanded and integrated into the armed forces of the DPR and LPR.
level 1 – sensory cells or internal cells; and level 2 – interconnected ganglion cells connected via synapse to epithelial or motor cells. Some have only two sheets of neurons. It also has been described that there are three major networks extending throughout Hydra's entire body. They are activated selectively during longitudinal contractions, elongations in response to light, and radial contractions; the additional network near the hypostome, the dome-shaped jut surrounding the mouth aperture, is activated during nodding (the gentle swaying of the hypostome and its tentacles to one side).
== Mechanism == As an aspartic protease, the dimerized HIV-1 PR functions through the aspartyl group complex, in order to perform hydrolysis. Of the two Asp25 residues on the combined catalytic active site of HIV-1 PR, one is deprotonated while the other is protonated, due to pKa differences from the micro-environment. In a general aspartic protease mechanism, once the substrate is properly bound to the active site of the enzyme, the deprotonated Asp25 catalytic amino acid undergoes base catalysis, rendering the incoming water molecule a better nucleophile by deprotonating it. The resulting hydroxyl ion attacks the carbonyl carbon of the peptide bond, forming an intermediate with a transient oxyanion, which is stabilized by the initially protonated Asp25. The oxyanion re-forms a double bond, leading to the cleavage of the peptide bond between the two amino acids, while the initially deprotonated Asp25 undergoes acid catalysis to donate its proton to the amino group, making the amino group a better leaving group for complete peptide bond cleavage and returning to its original deprotonated state. While HIV-1 PR shares many of the same characteristics as a non-viral aspartic protease, some evidence has shown that HIV-1 PR catalyzes hydrolysis in a concerted manner; in other words, the nucleophilic water molecule and the protonated Asp25 simultaneously attack the scissile peptide bond during catalysis.
Under Omani Arabs, Zanzibar became East Africa's main slave port, with as many as 50,000 African slaves passing through every year during the 19th century. Some historians estimate that between 11 and 18 million African slaves crossed the Red Sea, Indian Ocean, and Sahara Desert from 650 to 1900 AD. Eduard Rüppell described the losses of Nuba slaves from Southern sudan being transported on foot to Egypt: "after the Daftardar bey's 1822 campaign in the southern Nuba mountains, nearly 40,000 slaves were captured. However, through bad treatment, disease and desert travel barely 5,000 made it to Egypt." W.A. Veenhoven wrote: "The German doctor, Gustav Nachtigal, an eye-witness, believed that for every slave who arrived at a market three or four died on the way ... Keltie (The Partition of Africa, London, 1920) believes that for every slave the Arabs brought to the coast at least six died on the way or during the slavers' raid. Livingstone puts the figure as high as ten to one." Systems of servitude and slavery were common in parts of Africa, as they were in much of the ancient world. In many African societies where slavery was prevalent, the slaves were not treated as chattel slaves and were given certain rights in a system similar to indentured servitude elsewhere in the world. The forms of slavery in Africa were closely related to kinship structures. In many African communities, where land could not be owned, enslavement of individuals was used as a means to increase the influence a person had and expand connections.
Sources: en.wikipedia.org
=== Financial issues and conflicts of interest === Ethical considerations in financial include accurate billing practices and clearly defined financial relationships. Doctors have both a professional duty and obligation under the justice principle to ensure that patients are provided the same care regardless of status or ability to pay. However, informal copayment forgiveness may have legal ramifications and the providing professional courtesy may have negatively impact care. Dotors must disclose all possible conflicts of interest including financial relationships, investments, research and referral relationships, and any other instances that may subjugate or give the appearance of subjugating patient care to self-interest.
Oligonucleotide phosphorothioates (OPS) are modified oligonucleotides where one of the oxygen atoms in the phosphate moiety is replaced by sulfur. Synthesis of OPS is very similar to that of natural oligonucleotides. The difference is that the oxidation step is replaced by sulfur transfer reaction (sulfurization) and that the capping step is performed after the sulfurization.
It is available as the following salts, in approximate descending order of frequency of use: bitartrate, phosphate, hydrochloride, tartrate, hydroiodide, methyliodide, hydrobromide, sulfate, and thiocyanate. The salt to free base conversion factors are 0.67 for the bitartrate, 0.73 for the phosphate, and 0.89 for the hydrochloride. Dihydrocodeine is the parent drug of a series of moderately strong narcotics including, among others, hydrocodone, nicocodeine, nicodicodeine, thebaine and acetyldihydrocodeine. It is an original member and chemical base of a number of similar semi-synthetic opioids such as acetyldihydrocodeine, dihydrocodeinone enol acetate, dihydroisocodeine, nicocodeine, and nicodicodeine. Whereas converting codeine to morphine is a difficult and unrewarding task, dihydrocodeine can be converted to dihydromorphine with very high yields (over 95%). Dihydromorphine is widely used in Japan. The dihydromorphine can be quantitatively converted to hydromorphone using potassium tert butoxide. Dihydrocodeine can be presumptively detected by the Froehde reagent.
=== Knudsen effect === Aerogels may have a thermal conductivity smaller than that of the gas they contain. This is caused by the Knudsen effect, a reduction of thermal conductivity in gases when the size of the cavity encompassing the gas becomes comparable to the mean free path. Effectively, the cavity restricts the movement of the gas particles, decreasing the thermal conductivity in addition to eliminating convection. For example, thermal conductivity of air is about 25 mW·m−1·K−1 at standard temperature and pressure (STP) and in a large container, but decreases to about 5 mW·m−1·K−1 in a pore 30 nanometers in diameter.
Telithromycin is the first ketolide antibiotic to enter clinical use and is sold under the brand name of Ketek. It is used to treat community acquired pneumonia of mild to moderate severity. After significant safety concerns, the US Food and Drug Administration sharply curtailed the approved uses of the drug in early 2007. Telithromycin is a semi-synthetic erythromycin derivative. It is created by substituting a ketogroup for the cladinose sugar and adding a carbamate ring in the lactone ring. An alkyl-aryl moiety is attached to this carbamate ring. Furthermore, the oxygen at the 6 position is methylated, as is the case with clarithromycin, to achieve better acid-stability. It was patented in 1994 and approved for medical use in 2001.
Sources: en.wikipedia.org
== Awards == Advance for Medical Laboratory Professionals received the Corporate Recognition Award from the Pennsylvania chapter of the American Society for Clinical Laboratory Science. In 2006, the trade journal's editor, Matthew Patton, won an award in the Awards for Publication Excellence in the Editorial and Advocacy Writing category
==== Reversibility and irreversibility ==== In many cases, denaturation is reversible (the proteins can regain their native state when the denaturing influence is removed). This process can be called renaturation. This understanding has led to the notion that all the information needed for proteins to assume their native state was encoded in the primary structure of the protein, and hence in the DNA that codes for the protein, the so-called "Anfinsen's thermodynamic hypothesis". Denaturation can also be irreversible. This irreversibility is typically a kinetic, not thermodynamic irreversibility, as a folded protein generally has lower free energy than when it is unfolded. Through kinetic irreversibility, the fact that the protein is stuck in a local minimum can stop it from ever refolding after it has been irreversibly denatured.
== Medical uses == Phenibut is used in Russia, Ukraine, Belarus and Latvia as a pharmaceutical drug to treat anxiety and to improve sleep (e.g., in the treatment of insomnia). It is also used for various other indications, including the treatment of asthenia, depression, alcoholism, alcohol withdrawal syndrome, post-traumatic stress disorder, stuttering, tics, vestibular disorders, Ménière's disease, dizziness, for the prevention of motion sickness, and for the prevention of anxiety before or after surgical procedures or painful diagnostic tests.
== Actions in the brain == DAO acts in the brain to oxidize specific D-amino acids using the FAD region (flavin adenine dinucleotide region) and is commonly thought to be produced in the hindbrain, although there is new evidence of DAO expression in the forebrain as well. The DAO present in the forebrain seems to be inactive, however, causing speculation on the topic of DAO function in the forebrain as opposed to the hindbrain where the function is more well-known. The consensus is that DAO is produced and is active in glial cells, most specifically in cerebellar type-1 and type-2 astrocytes, and the D-serine amino acid that is produced by DAO in these cells has been shown to increase synaptic NMDA receptor activity.
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.
Cardarine is an investigational synthetic compound that acts as a PPARδ agonist. It is also known as GW501516 and has been studied mainly in preclinical research. It is not an approved medicine.