Nuclear receptor raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-02-09 and is reviewed periodically as new material appears.
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.
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.
GW501516 acts on PPARδ, a nuclear receptor that helps regulate fatty acid oxidation and energy homeostasis. In animal studies, activation of this receptor was associated with increased endurance and changes in lipid metabolism. Human trials examined effects on blood lipids and other metabolic markers, but the compound did not advance to approval. Rodent studies later reported tumors in multiple tissues at doses used in those experiments. Whether those findings translate to human risk remains uncertain, and the clinical relevance of the animal data is still debated.
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.
| 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. |
GW501516 binds and activates PPARδ, a nuclear receptor that influences transcription of genes involved in fatty acid oxidation and energy use. Activation shifts some metabolic pathways in preclinical models, which is why the compound has been studied for lipid disorders and exercise-related endpoints. The exact downstream effects in humans are incompletely mapped. PPARδ is expressed in many tissues, including skeletal muscle, liver, and adipose tissue, so broad activation may have varied consequences. Researchers continue to examine how selective or partial activation might alter the balance between benefits and risks.
Published human data are sparse and mostly come from early-phase trials. Those studies examined short-term changes in lipids, glucose, and exercise capacity, but they were not large enough to establish efficacy or long-term safety. Some animal experiments reported increased running endurance, yet such findings do not prove a performance benefit in people. Anti-doping laboratories detect GW501516 and its metabolites in urine or blood using liquid chromatography-tandem mass spectrometry. Detection windows depend on dose, sample type, and individual metabolism. The method is sensitive enough to identify trace residues in tested samples.
Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.
Anti-doping laboratories detect GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be used in some programs. Detection depends on factors such as dose, timing, metabolism, and the sensitivity of the assay. Published methods describe limits of detection in the low nanogram per milliliter range for related compounds. Exact detection windows are not fixed for all situations and remain an area of ongoing study.
== Quality of living == Bangkok was ranked 129th of 230 (1=best quality of living, 230=worst quality of living) cities worldwide in Mercer's 2016 Quality of Living survey rankings. Vienna was ranked number 1, Baghdad last. Singapore (26) is the highest-ranked Asian city. Behind Singapore, the second highest-ranked city in Southeast Asia is Kuala Lumpur (86). Manila is ranked 136 and Jakarta 142. On the "personal safety" component of the ranking, Bangkok was ranked 173rd, due to political unrest and terrorist attacks.
=== Idiopathic === Recurrent apthous stomatitis (RAS): Recurrent ulceration found in the mouth with a wide variety of predisposing factors. However, the aetiology remains unclear. There are three forms of RAS: minor, major, and herpetiform. RAS is usually found in non-smokers and those from high socioeconomic background.
== Further research == As lenticule extraction techniques evolve, there is a possibility that extracted lenticules can be cryogenically preserved either for future donation, or re-implantation. Proof of concept has been carried out on primates where lenticules were extracted from monkeys and allogenically transplanted into other monkeys with positive results.
Sources: en.wikipedia.org
=== Red blood cell production === Erythropoietin is an essential hormone for red blood cell production. Without it, definitive erythropoiesis does not take place. Under hypoxic conditions, the kidney will produce and secrete erythropoietin to increase the production of red blood cells by targeting CFU-E, proerythroblast and basophilic erythroblast subsets in the differentiation. Erythropoietin has its primary effect on red blood cell progenitors and precursors (which are found in the bone marrow in humans) by promoting their survival through protecting these cells from apoptosis, or cell death. Erythropoietin is the primary erythropoietic factor that cooperates with various other growth factors (e.g., IL-3, IL-6, glucocorticoids, and SCF) involved in the development of erythroid lineage from multipotent progenitors. The burst-forming unit-erythroid (BFU-E) cells start erythropoietin receptor expression and are sensitive to erythropoietin. Subsequent stage, the colony-forming unit-erythroid (CFU-E), expresses maximal erythropoietin receptor density and is completely dependent on erythropoietin for further differentiation. Precursors of red cells, the proerythroblasts and basophilic erythroblasts also express erythropoietin receptor and are therefore affected by it.
Walthard cell rests, sometimes called Walthard cell nests, are a benign cluster of epithelial cells most commonly found in the connective tissue of the fallopian tubes, but also seen in the mesovarium, mesosalpinx and ovarian hilus.
== Diagnosis == A diagnosis of postinflammatory hyperpigmentation is established based upon its clinical presentation coupled with a recent history of inflammation over the same area. Diagnostic tests are not required, but can rule out some other conditions, such as Addison's disease or systemic lupus erythematosus. Wood’s lamp evaluation can be used in the diagnosis as well.
Sources: en.wikipedia.org
York Chow, the health secretary of Hong Kong, said he thought animal feeds might be the source of the contamination and announced that the Hong Kong Centre for Food Safety would henceforward be testing all mainland Chinese pork, farmed fish, animal feed, chicken meat, eggs, and offal products for melamine. As of July 2010, Chinese authorities were still reporting some seizures of melamine-contaminated dairy product in some provinces, though it was unclear whether these new contaminations constituted wholly new adulterations or were the result of illegal reuse of material from the 2008 adulterations. On characterization and treatment of urinary stones in affected infants, The New England Journal of Medicine printed an editorial in March 2009, along with reports on cases from Beijing, Hong Kong and Taipei. Urinary calculi specimens were collected from 15 cases treated in Beijing and were analyzed as unknown objects for their components at Beijing Institute of Microchemistry using infrared spectroscopy, nuclear magnetic resonance, and high performance liquid chromatography. The result of the analysis showed that the calculus was composed of melamine and uric acid, and the molecular ratio of uric acid to melamine was around 2:1.
== History == Prior to 1960, the thymus gland, which lies in the cervical thoracic area, was thought to be of little importance. In adult animals, the thymus is almost non-existent because it atrophies as animals reach adulthood. It was observed, however, that when pre-adolescent animals are thymectomized, they experience a variety of maladies including increased incidence of infection, failure to grow, neuromuscular disorders, cancer, etc., collectively known as “wasting disease”. The greater susceptibility to infection was shown to be directly attributable to a dramatic decrease in peripheral blood lymphocytes in thymectomized animals. By 1964 it had been demonstrated that regulatory factors extracted from the thymus gland could prevent many of the manifestations of wasting disease. This suggested that the thymus produces substances important in the development of immunity. It was not until 1971 that it was discovered that thymus-derived lymphocytes (T-cells) were important regulators of bone-marrow-derived antibody-producing lymphocytes (B-cells). After the discovery that the thymus was producing profound regulatory factors, several groups of scientists began trying to extract and purify this factor from thymus glands in much the same manner that insulin was prepared from the pancreas for therapeutic use in diabetes. The difficulty was that the thymus is a very small gland and produces very small quantities of the factor. Thus, purification techniques did not allow appropriate pure fractions to be produced in sufficient quantities.
A variety of LSD analogues are known. Many of them retain psychedelic effects similarly to LSD, although most have reduced potency and none are notably more potent than LSD. Examples include ergine (lysergic acid amide; LSA), isoergine (iso-LSA), lysergic acid hydroxyethylamide (LSH), ergonovine (ergometrine), methylergonovine (methylergometrine), methysergide, ETH-LAD, PRO-LAD, AL-LAD, 1-methyl-LSD (MLD-41), MiPLA, and LA-SS-Az (LSZ), among many others. Presumed or known prodrugs of LSD, including 1A-LSD (ALD-52), 1P-LSD, and 1V-LSD, have been developed or encountered. Some non-hallucinogenic LSD analogues, such as lisuride and 2-bromo-LSD (BOL-148), are known as well. They are lower-efficacy serotonin 5-HT2A receptor partial agonists and can notably act as hallucinogen antagonists against LSD. In addition to lysergamide derivatives, simplified or "partial" LSD analogues or seco-LSD compounds, such as NDTDI (8,10-seco-LSD), UCD0179 (3,5-seco-LSD), 10,11-seco-LSD (UCD0121), and N-DEAOP-NMT, are known. A notable bioisostere of LSD is JRT, the isotryptamine analogue of LSD and a psychedelic and psychoplastogen which is under investigation for the potential treatment of schizophrenia. Another notable analogue of LSD is LSD-Quinoline, in which the indole ring within the ergoline ring system is replaced with a quinoline ring.
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.
No. Cardarine is a PPARδ agonist, while selective androgen receptor modulators act on androgen receptors. The two classes differ in receptor target and downstream effects.