This is a working overview of nuclear receptor, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-06-17. Anything still debated is marked as such rather than presented as settled.
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.
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.
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 |
|---|---|---|
| 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 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.
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.
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.
=== Neutering status in animals === In veterinary medicine, AMH measurements are used to determine neutering status in male and female dogs and cats. AMH levels can also be used to diagnose cases of ovarian remnant syndrome.
Infliximab works by binding to TNF, stopping its inflammatory effects. It was initially used for the treatment of Crohn's disease and it became the first FDA approved TNF inhibitor in 1998. Infliximab as well as other TNF inhibitors like adalimumab, certolizumab, and golimumab are currently the most common biologics used in the treatment of both Crohn's disease and ulcerative colitis. The other main categories of biologics that treat IBD are integrin receptor antagonists such as vedolizumab and natalizumab and interleukin antagonists like ustekinumab.
=== Regulation === Translation is one of the key energy consumers in cells, hence it is strictly regulated. Numerous mechanisms have evolved that control and regulate translation in eukaryotes as well as prokaryotes. Regulation of translation can impact the global rate of protein synthesis which is closely coupled to the metabolic and proliferative state of a cell. To study this process, scientists have used a wide variety of methods such as structural biology, analytical chemistry (mass-spectrometry based), imaging of reporter mRNA translation (in which the translation of a mRNA is linked to an output, such as luminescence or fluorescence), detecting it via radioactive amino acid incorporation, and next-generation sequencing based methods. Other methods such as toeprinting assay can also be used to determine the location of ribosomes of a particular mRNA in vitro, and footprints of other proteins regulating translation. To delve deeper into this intricate process, scientists typically use a technique known as ribosome profiling. This method enables researchers to take a snapshot of the translatome, showing which parts of the mRNA are being translated into proteins by ribosomes at a given time. Ribosome profiling provides valuable insights into translation dynamics, revealing the complex interplay between gene sequence, mRNA structure, and translation regulation. Expanding on this concept, single-cell ribosome profiling, is a technique that allows the study of the translation process at the resolution of individual cells.
== Materials used == Injectable fillers are composed of a wide range of natural and synthetic biomaterials, which can be categorized as resorbable or non-resorbable polymers. Injectable fillers are frequently formulated as hydrogels composed of hydrophilic polymer networks that can retain large amounts of water while maintaining structural integrity. Common materials include naturally derived polymers such as hyaluronic acid, gelatin, collagen, chitosan, alginate, and polysaccharides, as well as synthetic polymers like polyethylene glycol (PEG), poly(lactic acid), poly(methyl methacrylate), polyacrylamide, and dextran. These materials are often selected for their biocompatibility and structural similarity to the extracellular matrix, enabling integration with surrounding tissues. To enable in situ gelation, polymers are typically functionalized with reactive groups such as phenols, amines, or glutamine residues, allowing controlled crosslinking after injection. In advanced formulations, these hydrogel matrices may also serve as carriers for therapeutic fillers, including cells, proteins, or drugs, expanding their functionality beyond structural augmentation. Hyaluronic acid
Sources: en.wikipedia.org
==== Excess compensation ==== Effective in 2026, certain tax-exempt organizations must pay an excise tax on compensation exceeding $1 million paid to any current and former employee, rather than only to its top five most highly compensated employees for current and prior years.
=== Graphic content === In June 2021, TikTok made an apology after a shock video, showing a girl dancing which then cuts to a graphic scene of a man being beheaded by a saw, went viral. The video has been put on TikTok's blacklist, which detects it before being uploaded. TikTok has previously worked to remove graphic content from its platform, including a suicide video that circulated in September 2020, which had appeared among the recommended clips of TikTok's For You section.
== Medical uses == Total parenteral nutrition (TPN) is provided when the gastrointestinal tract is nonfunctional because of an interruption in its continuity (it is blocked, or has a leak – a fistula) or because its absorptive capacity is impaired. It has been used for comatose patients, although enteral feeding is usually preferable, and less prone to complications. Parenteral nutrition is used to prevent malnutrition in patients who are unable to obtain adequate nutrients by oral or enteral routes. The Society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition recommends waiting until the seventh day of hospital care to administer parenteral nutrition.
Glucagon receptor Glucagon-like peptide 1 receptor Glucagon-like peptide 2 receptor Gastric inhibitory polypeptide receptor The first three receptors bind closely related peptide hormones (glucagon, glucagon-like peptide-1, glucagon-like peptide-2) derived from the proglucagon polypeptide. The last receptor binds gastric inhibitory polypeptide.
== Functions == The integumentary system has multiple roles in maintaining the body's equilibrium. All body systems work in an interconnected manner to maintain the internal conditions essential to the function of the body. The skin has an important job of protecting the body and acts as the body's first line of defense against infection, temperature change, and other challenges to homeostasis. Its main functions include:
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.