A practical reference on Nuclear receptor: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-11-20. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| 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 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.
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 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.
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.
Cardarine is a synthetic compound also known as GW501516, GW-501516, and sometimes endurobol. It was developed as a selective agonist of peroxisome proliferator-activated receptor delta, a nuclear receptor involved in fatty acid oxidation and energy metabolism. The compound was studied in preclinical models for metabolic and cardiovascular conditions, but it did not become a marketed human medicine. In regulatory and anti-doping contexts, it is treated as a prohibited substance rather than a licensed medicine.
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.
Jung's acquaintance with alchemy came between 1928 and 1930 when he was introduced to a manuscript of The Secret of the Golden Flower, translated by Richard Wilhelm. The work and writings of Jung from the 1930s onwards shifted to a focus on the psychological significance of alchemy. In 1944, Jung published Psychology and Alchemy, in which he analyzed the alchemical symbols and came to the conclusion that there is a direct relationship between them and the psychoanalytical process. He argued that the alchemical process was the transformation of the impure soul (lead) to perfected soul (gold), and a metaphor for the individuation process. In 1963, Mysterium Coniunctionis first appeared in English as part of The Collected Works of C. G. Jung. Mysterium Coniunctionis was Jung's last major book and focused on the "Mysterium Coniunctionis" archetype, known as the sacred marriage between the sun and moon. Jung argued that the stages of the alchemists, the blackening, the whitening, the reddening, and the yellowing, could be taken as symbolic of individuation—his chosen term for personal growth (75).
=== U.S. Department of Agriculture === In 1905, Pennington worked for the U.S. Department of Agriculture Bureau of Chemistry, which later became the U.S. Food and Drug Administration. Her director at the Bureau of Chemistry, Harvey W. Wiley, encouraged her to apply for a position as chief of the newly created Food Research Laboratory, which had been established to enforce the Pure Food and Drug Act of 1906. She was submitted to the position under the name M.E. Pennington in order to hide her gender. She accepted the position in 1907 and became the first female lab chief. One of her major accomplishments was the development of standards for the safe processing of chickens raised for human consumption. She also served as head of an investigation of refrigerated boxcar design and served on Herbert Hoover's War Food Administration during World War I.
Art to be viewed from space – The Nazca Lines were created by the ancient Nazca culture in modern-day Peru. The Nazca built these artworks, which could only be viewed from the sky or from space. It was as if the Nazca were building monuments, which only their gods could view from up in the sky. Some of these artworks, otherwise known as the Nazca Lines, could only be viewed from the sky and each one of these works of Nazca art spans several miles across in size and dimension in the Sechura Desert. Aqueducts – The ancient Andean cultures, such as Chimu, Moche and Nazca, lived in dry environments, yet they sustained large scale agriculture consisting of a wide variety of crops by employing aqueducts connecting various freshwater sources, such as mountain streams and lakes to their agricultural fields which were sometimes injecting pressure with the aid of puquios (wind-based water pumps). The Inca later expanded on these previously constructed aqueducts and built a more complex and large aqueduct system in the Inca Empire. The Mesoamerican Aztecs also constructed complex, dual-pipe aqueducts to supply their vast city of Tenochtitlan. Aspirin – Indigenous Americans have been using willow tree bark for thousands of years to reduce fever and pain as were the peoples of Assyria, Sumer, Ancient Egypt and Ancient Greece. When chemists analyzed willows in the last century, they discovered salicylic acid; the basis of the modern drug aspirin.
Sources: en.wikipedia.org
==== Affinity selection ==== A generalized AS-MS workflow begins with the pre-incubation of purified protein solutions (i.e. target proteins) with chemical libraries in microplates. Assays can be designed to contain sufficiently high protein concentrations to prevent competition for binding sites between structural analogs, ensuring that hits across a range of affinities can be identified; inversely, assays can contain low protein concentrations to allow for distinction between high and low affinity analogs and to inform structure-activity relationships. The choice of a chemical library is less stringent than other high-throughput screening strategies owing to the lack of functional readouts, which would otherwise require deconvolution of the source compound that generates biological activity. Thus, the typical range for AS-MS is 400-3,000 compounds per pool. Other considerations for screening are more practical, such as a need to balance desired compound concentration, which is usually in the micromolar range, with the fact that compound stock solutions are typically stored as 10 millimolar solutions, effectively capping the number of compounds screened in the thousands. After appropriate test compounds and targets are selected and incubated, ligand-protein complexes can be separated by a variety of means.
Insect burrow fossils can sometimes be distinguished from real egg fossils by the presence of "scratch marks" on their surface left by the insect during the burrow's original excavation. Fossil insect pupae can also resemble eggs. After death and burial, the decomposition of a deceased pupa would leave a gap in the sediment that could be filled with minerals carried by groundwater, forming an egg-like cast. These pseudo-eggs can be recognized by their small size (usually not much longer than a centimeter or two) and lack of an eggshell with its typical anatomy. Stones: The erosive effects of water can sometimes round rocks into egg-like shapes.
is the mass generation rate of the substance - assumed to be a constant, i.e. not a function of time (equal to zero for exogenous (foreign) substances/drugs) [mmol/min] or [mol/s] t is dialysis time or time since injection of the substance/drug [min] or [s] V is the volume of distribution or total body water [L] or [m3] K is the clearance [mL/min] or [m3/s] C is the concentration [mmol/L] or [mol/m3] (in the United States often [mg/mL]) From the above definitions it follows that
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.
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.