Nuclear receptor comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-05-29. Where a claim depends on a specific study, the study is described rather than over-claimed.
Activation of PPARδ changes transcription of genes involved in fatty acid transport, mitochondrial function, and skeletal muscle fuel preference. In rodent studies, pharmacological PPARδ activation was associated with increased endurance and altered body composition. These findings generated interest in performance enhancement, but species differences and study designs limit direct extrapolation to humans. Small human trials were conducted in the 2000s and later discontinued. The extent to which cardarine produces similar metabolic or performance effects in people remains an open question.
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
Cardarine is a common name for GW501516, an investigational compound developed in the 1990s for metabolic conditions. It acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in lipid and energy metabolism. The compound is frequently mislabeled as a selective androgen receptor modulator, or SARM, but its molecular target is different. GW501516 reached early clinical testing before development was discontinued. It has no approved therapeutic use in any country. The name cardarine is not a formal international nonproprietary name.
Regulatory treatment varies, but cardarine is not approved as a medicine. Sports authorities list GW501516 as a prohibited substance, and it is banned at all times under the World Anti-Doping Agency code. Many countries restrict sales for human consumption, while online vendors market it as a research chemical. Such products may lack purity data, and their actual contents can differ from the label. Purchasing or possessing cardarine may carry legal consequences depending on jurisdiction. The compound is not a dietary supplement ingredient in regulated markets.
Clinical development stopped after rodent studies showed tumors at multiple sites. Whether those findings predict human cancer risk remains an open question, but they led sponsors to discontinue programs. Human safety data are limited to small, short-term studies that were not designed to assess cancer risk. Reported effects in those studies included changes in blood lipids, but the evidence is insufficient for medical use. Long-term consequences of nonmedical use are not well characterized. Questions about dose, duration, and individual susceptibility remain unresolved.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic PPARδ agonist | Not a steroid or a selective androgen receptor modulator. |
| Common synonyms | Cardarine, GW501516, GW-501516, endurobol | Names vary by supplier and literature source. |
| Appearance | White to off-white powder | Consistent with many small-molecule research chemicals. |
| Solubility | Low in water; soluble in DMSO and ethanol | Often prepared in organic solvent for laboratory work. |
| Primary target | PPARδ (NR1C2) | Nuclear receptor involved in lipid and energy metabolism. |
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.
GW501516 acts as an agonist at the peroxisome proliferator-activated receptor delta, a nuclear receptor that regulates gene expression. Activation shifts transcription toward genes involved in fatty acid uptake, oxidation, and energy expenditure. The compound does not bind the androgen receptor and therefore differs from anabolic steroids and SARMs. In rodent models, this metabolic shift has been linked to increased running endurance and reduced fat accumulation. The exact downstream pathways in humans remain incompletely characterized.
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.
Laboratory detection of GW501516 commonly uses liquid chromatography coupled with tandem mass spectrometry. The method can identify the parent compound or its metabolites in urine and blood after sample cleanup. Protein precipitation, solid-phase extraction, or enzymatic hydrolysis may precede analysis, depending on the matrix. Reference standards are required for accurate quantification and confirmation. Because the compound is not approved, testing often occurs in anti-doping, forensic, or research settings rather than routine clinical care. Results are reported with limits of detection and quantification.
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.
The division had been so rushed to get this brigade to the battlefront that it ignored individual deployment criteria. Paratroopers who had just returned from Vietnam now found themselves suddenly going back. The howl of soldier complaints was so vehement that the Department of the Army was soon forced to give each trooper who had deployed to Vietnam with the 3d Brigade the option of returning to Fort Bragg or remaining with the unit. To compensate for the abrupt departures from home for those who elected to stay with the unit, the Army authorized a month leave at the soldiers' own expense or a two-week leave with government aircraft provided for special flights back to North Carolina. Of the 3,650 paratroopers who had deployed from Fort Bragg, 2,513 elected to return to the United States at once. MACV had no paratroopers to replace them, and overnight the brigade was transformed into a separate light infantry brigade, airborne in name only.
=== Examples === In Belews Lake North Carolina, 19 species of fish were eliminated from the lake due to 150–200 μg Se/L wastewater discharged from 1974 to 1986 from a Duke Energy coal-fired power plant. At the Kesterson National Wildlife Refuge in California, thousands of fish and waterbirds were poisoned by selenium in agricultural irrigation drainage.
== Market == As of 2012, the pharmaceutical industry had expressed strong interest in developing botanical drugs, with more than 500 applications pending at the FDA. Part of the interest stems from a desire to address the Chinese market, where herbal medicines remain widely used and had $13 billion in sales in 2011.
Sources: en.wikipedia.org
ACAM2000 is a smallpox vaccine manufactured by Emergent Biosolutions. It provides protection against smallpox for people determined to be at high risk for smallpox infection. ACAM2000 is a live replicating vaccinia virus vaccine. Like other smallpox vaccines, it also works as a vaccine for mpox and was approved for this purpose in 2024.
The Legion of Merit is a decoration of the United States and is awarded to foreign military personnel in four grades and to U.S. military personnel without distinction of degree. The following are notable recipients within the award.
==== College of Interdisciplinary and Continuing Studies ==== The College of Interdisciplinary and Continuing Studies provides degree programs to learners with previously earned college credits but no degree, affording the opportunity of degree completion. The interdisciplinary nature of the programs allows students to draw from expertise and resources across campus to design a program of study aligned with local, national and global workforce opportunities.
, is a quantity that may be measured in experimental physics. It bears significance because the electron mass me is difficult to measure directly, and is instead derived from measurements of the elementary charge e and
Sources: en.wikipedia.org
== Awards == In 2008, Horsley was a regional finalist in the Blavatnik Awards for Young Scientists. In 2012, Horsley received the Presidential Early Career Award for Scientists and Engineers for her research of skin cell generation. Also in 2012, she was one of two recipients and received the Rosalind Franklin Young Investigator Award, presented every three years by the Genetics Society of America and the American Society of Human Genetics to two top women scientists in the field of genetics. In 2016, Horsley received the Montagna Lecture Award from the Society of Investigative Dermatology. In 2018, Horsley received the Graduate Division in Biomedical and Biological Sciences Distinguished Alumnus award from Emory University. Horsley's work and lab are supported by federal funding from the National Institutes of Health.
== Excess == Elevated HbA2 levels that surpass 3.5%, indicate a potential mutation in the beta-globin genes. This potential mutation typically occurs in the -87 and -88 promoter region, which affects the proximal CACCC box. Another factor leading to increased HbA2 levels involves the deletion of bases that are placed adjacent to the beta-globin genes. This deletion results in a heightened HbA2 levels due to removing the locus control regions in the beta promoter. This specific promoter is crucial for gene interactions with both gamma and beta globin genes, which also enables both genes to be expressed.
During a match against Borussia Mönchengladbach in 1996, Wenger presided over Rice's caretaker duties at Arsenal, and ordered the team to switch from their preferred 3–5–2 formation to 4–4–2. The tactical change did not have its desired effect, as Arsenal lost the game having led before Wenger's half-time instruction. For much of the 1996–97 season, Arsenal continued to play 3–5–2 as it was the only formation the defenders were comfortable with, as well as injuries unsettling the side. In Wenger's second season at the club, he reinstated 4–4–2 and focused on strengthening the front six, by signing wingers Overmars and Luís Boa Morte and partnering Vieira with Petit. According to Jonathan Wilson, the system was similar to 4–3–3, as Overmars often pushed higher up the field and Parlour played alongside Vieira and Petit to solidify the midfield. Needing to compensate deficiencies in attack the following season, Wenger relied on his experienced defence to direct games, which conceded 17 goals in 38 league matches. From then on, Wenger deployed an unconventional 4–4–2 with a greater emphasis on attack and movement; his teams between 2001 and 2004 were dominant on the left flank. By the 2005–06 season, clubs in England were increasingly in favour of using the 4–5–1 system. Wenger, having earlier suggested he would never resort to a negative system, later adopted the formation for Champions League matches. The decision to pack the midfield and play a lone striker resulted in Arsenal reaching the final.
== Early political career == He transitioned into politics in 1977, when he served one term on the East Hartford Board of Education. He then served two terms on the East Hartford Town Council. In 1982, Larson was elected to the Connecticut State Senate from the 3rd district, based in East Hartford. He served six terms in that body, the last four as president pro tempore. In 1994, Larson left the state senate and sought the Democratic nomination for governor of Connecticut, losing to Bill Curry in the primary. After being defeated for governor, Larson entered private business for several years but was able to maintain his political credentials.
FAD-dependent proteins function in a large variety of metabolic pathways including electron transport, DNA repair, nucleotide biosynthesis, beta-oxidation of fatty acids, amino acid catabolism, as well as synthesis of other cofactors such as CoA, CoQ and heme groups. One well-known reaction is part of the citric acid cycle (also known as the TCA or Krebs cycle); succinate dehydrogenase (complex II in the electron transport chain) requires covalently bound FAD to catalyze the oxidation of succinate to fumarate by coupling it with the reduction of ubiquinone to ubiquinol. The high-energy electrons from this oxidation are stored momentarily by reducing FAD to FADH2. FADH2 then reverts to FAD, sending its two high-energy electrons through the electron transport chain; the energy in FADH2 is enough to produce 1.5 equivalents of ATP by oxidative phosphorylation. Some redox flavoproteins non-covalently bind to FAD like Acetyl-CoA-dehydrogenases which are involved in beta-oxidation of fatty acids and catabolism of amino acids like leucine (isovaleryl-CoA dehydrogenase), isoleucine, (short/branched-chain acyl-CoA dehydrogenase), valine (isobutyryl-CoA dehydrogenase), and lysine (glutaryl-CoA dehydrogenase). Additional examples of FAD-dependent enzymes that regulate metabolism are glycerol-3-phosphate dehydrogenase (triglyceride synthesis) and xanthine oxidase involved in purine nucleotide catabolism.
Sources: en.wikipedia.org
Cardarine is a common name for GW501516, a synthetic PPARδ agonist. It is not a steroid or a selective androgen receptor modulator. It was developed and studied as a research compound for metabolic pathways.
It binds to and activates PPARδ, a nuclear receptor that regulates genes related to fatty acid oxidation and energy use. This activation alters transcription in tissues such as skeletal muscle and liver. The full range of downstream effects in humans is not fully established.
No, cardarine is not known to occur naturally in plants, animals, or humans. It is a synthetic molecule produced for laboratory research. Products labeled as cardarine should therefore be treated as manufactured chemicals with variable purity.
No. Cardarine is GW501516, a PPARδ agonist, while SARMs act on androgen receptors. The two classes are often grouped in informal discussions despite different mechanisms.