nuclear receptor is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-03-09. Numbers and descriptions here follow the published literature rather than marketing material.
Regulatory treatment of SR9009 varies by country and region. It is not approved as a pharmaceutical, and several jurisdictions restrict its sale for human consumption. Some authorities classify it as a research chemical, a prescription-only substance, or a prohibited performance-enhancing agent in sport. Purchasers may encounter certificates of analysis, but these documents do not guarantee identity, purity, or legality. In research settings, institutional safety reviews and controlled procurement help ensure that materials are handled under appropriate oversight. The absence of harmonized rules means that legal status can change and requires verification.
Analytical identification of SR9009 typically relies on liquid chromatography coupled with tandem mass spectrometry. In biological samples, researchers first separate the compound from matrix components using protein precipitation, liquid-liquid extraction, or solid-phase extraction. High-performance liquid chromatography with ultraviolet detection and nuclear magnetic resonance spectroscopy can support structural confirmation of reference materials. Because SR9009 is a small, relatively lipophilic molecule, reverse-phase columns and acidic mobile phases are common. Laboratories often include isotope-labeled internal standards to improve quantification and to correct for ion suppression.
Mechanistically, SR9009 binds the ligand-binding domain of REV-ERBα/β and enhances recruitment of corepressor complexes. This represses target genes rather than activating them. Because REV-ERB proteins normally compete with ROR proteins at shared response elements, the net effect depends on tissue and timing. Researchers use SR9009 to probe how nuclear receptor signaling links the clock to metabolism, inflammation, and muscle biology. Findings are largely preclinical, and the precise contribution of each receptor subtype remains under study.
SR9009 is frequently discussed in fitness and research-chemical contexts, yet it has no approved medical indication. Regulatory agencies have not authorized it for human use, and it is not a standard prescription drug. Some sports organizations list it as a prohibited substance because of its potential performance-enhancing properties. Published human data are sparse, so claims about its effects in people often rely on animal models or anecdotal reports. Quality and identity of online materials can vary widely.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | SR9009; Stenabolic | Nickname is not a chemical name. |
| Typical analytical method | LC-MS/MS | Often with isotope-labeled internal standard. |
| Storage temperature | -20 °C | Desiccated and protected from light. |
| Solution stability | DMSO stock; avoid freeze-thaw | Store at -20 to -80 °C. |
| Regulatory status | Not approved; varies by country | May be restricted as research chemical. |
SR9009 is a synthetic small molecule studied as an agonist of REV-ERB nuclear receptors. REV-ERB alpha and REV-ERB beta help regulate circadian rhythms and metabolic gene expression. In laboratory research, SR9009 has been used to probe how these receptors affect skeletal muscle, liver, and adipose tissue. The compound was identified in academic drug-discovery work and is often described in scientific literature by its chemical name and research code. It is not an approved medicine, and human clinical data remain limited or absent.
SR9009 binds REV-ERB receptors and alters their repressive activity on target genes. This action can change transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. In rodent studies, treated animals have shown changes in muscle oxidative capacity and exercise performance, though effects vary by dose, duration, and model. The precise molecular steps connecting receptor binding to whole-body outcomes are still an active area of investigation. Findings in animals do not automatically translate to humans.
Analytical chemists detect SR9009 with liquid chromatography-tandem mass spectrometry, commonly abbreviated LC-MS/MS. Sample preparation may involve protein precipitation, liquid-liquid extraction, or solid-phase extraction before analysis. Laboratories can target the parent compound or its metabolites, depending on the matrix and the purpose of testing. Anti-doping methods require sensitive and specific assays because concentrations in biological samples can be low. Reference standards and validated methods are essential for reliable identification and quantification.
Regulatory agencies have not approved SR9009 for human therapeutic use. It is typically sold as a research chemical with labels stating that it is not for human consumption. The World Anti-Doping Agency prohibits the substance in sport, generally under the category of non-approved substances. Customs and national laws may restrict importation, sale, or possession. Product quality and legal status can vary by country and vendor, and therapeutic claims are not permitted in regulated advertising because the compound lacks approval.
Several misconceptions surround SR9009. It is often described as a SARM, a steroid, or an exercise pill, but its known target is the REV-ERB receptor family. Rodent studies have examined exercise capacity and metabolic markers, yet human outcomes remain unproven. Oral bioavailability appears low in animals, and human pharmacokinetics are not well characterized. Online products may contain impurities or different compounds, so identity and purity testing are important for research use.
REV-ERB proteins typically suppress gene expression by recruiting corepressor complexes to DNA response elements. SR9009 binds these receptors and strengthens that repressive action in cell-based assays. Studies in rodents have reported changes in lipid handling, mitochondrial function, and exercise capacity after treatment. Such findings are often cited as evidence for metabolic effects, but species differences and limited pharmacokinetic data make direct translation to humans uncertain. Researchers continue to examine which effects are robust and which depend on specific experimental conditions.
SR9009 is frequently discussed alongside other REV-ERB ligands, including synthetic agonists and natural heme-related molecules. Its selectivity for REV-ERB over related nuclear receptors has been measured in binding and reporter assays, though off-target activity at higher concentrations is possible. The compound is prohibited in sport by the World Anti-Doping Agency, and it is not approved for any medical use in major jurisdictions. Products sold online may be labeled as research chemicals, and their identity and purity are not guaranteed by regulatory review.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. These receptors help regulate circadian rhythms, lipid metabolism, and inflammatory gene expression. In cell and animal experiments, SR9009 alters transcription of clock-controlled genes and metabolic pathways. The compound is not a hormone and does not resemble classical steroid structures. Its activity depends on binding to the ligand-binding domain of REV-ERB, where it can modify corepressor recruitment.
Research interest in SR9009 grew from studies of circadian biology and metabolic disease. Preclinical reports describe effects on exercise capacity, muscle metabolism, and blood lipid levels in rodents, but these findings come from controlled laboratory settings. The compound has low oral bioavailability in animals, which limits systemic exposure after swallowing. Investigators often use injected routes in experiments to achieve measurable plasma concentrations. Human clinical data are sparse, no approved therapeutic product exists, and whether animal effects translate to humans remains an open question.
Regulatory and sporting contexts treat SR9009 as a prohibited substance in many elite competitions. Its presence on banned lists reflects concerns about performance enhancement and unknown long-term safety. Analytical chemists have developed methods to detect the parent compound and its metabolites in urine and blood. Literature discussions distinguish between in vitro potency, animal pharmacology, and anecdotal human reports. The latter are difficult to verify because products sold online may lack purity or contain different compounds.
Just like the GT-X, the engine power of the European market GT-R was also lowered to produce 185 PS (136 kW; 182 hp). As per the first GT-X, 300 units special version of GT-R were produced known as GT-Ae. These shared the power output of the GT-R, but were 30 kg (66 lb) lighter, fitted with closer ratio gearboxes, and featured a larger top spoiler with a gap between the hatch and the spoiler to direct air to the new lower spoiler. The wiring for ABS, air conditioning, power mirrors, power windows, power locks, and sunroof was removed. Instead of using the GT-R's leather interior, the lighter cloth interior of the GT-X was used.
== Non-specific DNA-protein interactions == Structural proteins that bind DNA are well-understood examples of non-specific DNA-protein interactions. Within chromosomes, DNA is held in complexes with structural proteins. These proteins organize the DNA into a compact structure called chromatin. In eukaryotes, this structure involves DNA binding to a complex of small basic proteins called histones. In prokaryotes, multiple types of proteins are involved. The histones form a disk-shaped complex called a nucleosome, which contains two complete turns of double-stranded DNA wrapped around its surface. These non-specific interactions are formed through basic residues in the histones making ionic bonds to the acidic sugar-phosphate backbone of the DNA, and are therefore largely independent of the base sequence. Chemical modifications of these basic amino acid residues include methylation, phosphorylation and acetylation. These chemical changes alter the strength of the interaction between the DNA and the histones, making the DNA more or less accessible to transcription factors and changing the rate of transcription. Other non-specific DNA-binding proteins in chromatin include the high-mobility group (HMG) proteins, which bind to bent or distorted DNA. Biophysical studies show that these architectural HMG proteins bind, bend and loop DNA to perform its biological functions. These proteins are important in bending arrays of nucleosomes and arranging them into the larger structures that form chromosomes.
In June 2026, progressive political commentator Ta-Nehisi Coates published a Vanity Fair article entitled Did Kamala Harris's Silence on Gaza Cost Her the White House? He argued the US adhered to a "survivalist theory of democracy" and that there was a "bipartisan acceptance of innocent death as the cost of doing business in the Muslim and Arab world," including with respect to the Gaza war and genocide. He said this led to a "casual contempt" for Democrat leaders. He also referenced how the Democratic Party had refused to allow a Palestinian American to speak at the 2024 Democratic National Convention. He also argued the election was a matter of lesser-evil voting. Journalist Joy Reid claimed many African Americans could not connect with Harris due to "her sort of political inability to speak directly to the genocide."
The first of China's nuclear weapons tests took place in 1964, and its first hydrogen bomb test occurred in 1967 at Lop Nur. Tests continued until 1996, when the country signed the Comprehensive Nuclear-Test-Ban Treaty (CTBT), but did not ratify it. The number of nuclear warheads in China's arsenal remains a state secret. There are varying estimates of the size of China's arsenal. The Bulletin of the Atomic Scientists and Federation of American Scientists estimated in 2024 that China has a stockpile of approximately 438 nuclear warheads, while the United States Department of Defense put the estimate at more than 500 operational nuclear warheads, making it the third-largest in the world. China's policy has traditionally been one of no first use while maintaining a deterrent retaliatory force targeted for countervalue targets. According to a 2023 study by the National Defense University, China's nuclear doctrine has historically leaned toward maintaining a secure second-strike capability.
Sources: en.wikipedia.org
=== Anemia === Anemia can be a combined outcome caused by myelosuppressive chemotherapy, and possible cancer-related causes such as bleeding, blood cell destruction (hemolysis), hereditary disease, kidney dysfunction, nutritional deficiencies or anemia of chronic disease. Treatments to mitigate anemia include hormones to boost blood production (erythropoietin), iron supplements, and blood transfusions. Myelosuppressive therapy can cause a tendency to bleed easily, leading to anemia. Medications that kill rapidly dividing cells or blood cells can reduce the number of platelets in the blood, which can result in bruises and bleeding. Extremely low platelet counts may be temporarily boosted through platelet transfusions and new drugs to increase platelet counts during chemotherapy are being developed. Sometimes, chemotherapy treatments are postponed to allow platelet counts to recover. Fatigue may be a consequence of the cancer or its treatment, and can last for months to years after treatment. One physiological cause of fatigue is anemia, which can be caused by chemotherapy, surgery, radiotherapy, primary and metastatic disease or nutritional depletion. Aerobic exercise has been found to be beneficial in reducing fatigue in people with solid tumours.
== Background == The monoisotopic mass is not used frequently in fields outside of mass spectrometry because other fields cannot distinguish molecules of different isotopic composition. For this reason, mostly the average molecular mass or even more commonly the molar mass is used. For most purposes such as weighing out bulk chemicals only the molar mass is relevant since what one is weighing is a statistical distribution of varying isotopic compositions. This concept is most helpful in mass spectrometry because individual molecules (or atoms, as in ICP-MS) are measured, and not their statistical average as a whole. Since mass spectrometry is often used for quantifying trace-level compounds, maximizing the sensitivity of the analysis is usually desired. By choosing to look for the most abundant isotopic version of a molecule, the analysis is likely to be most sensitive, which enables even smaller amounts of the target compounds to be quantified. Therefore, the concept is very useful to analysts looking for trace-level residues of organic molecules, such as pesticide residue in foods and agricultural products. Isotopic masses can play an important role in physics, but physics less often deals with molecules. Molecules differing by an isotope are sometimes distinguished from one another in molecular spectroscopy or related fields; however, it is usually a single isotope change on a larger molecule that can be observed rather than the isotopic composition of an entire molecule.
=== Intra-articular injection === It is used to treat knee pain in patients with osteoarthritis who have not received relief from other treatments. It is injected into the joint capsule, to act as both a shock absorber and a lubricant for the joint. Thus sodium hyaluronate is used as a viscosupplement, administered through a series of injections into the knee, increasing the viscosity of the synovial fluid, which helps lubricate, cushion and reduce pain in the joint. It is generally used as a last resort before surgery and provides symptomatic relief, by recovering the viscoelasticity of the articular fluid, and by stimulating new production of synovial fluid. Use of sodium hyaluronate may reduce the need for joint replacement. Injections appear to increase in effectiveness over the course of four weeks, reaching a peak at eight weeks and retaining some effectiveness at six months, with greater benefit for osteoarthritis than oral analgesics. It may also be effective when used with the ankle joint.
Sources: en.wikipedia.org
The most common approach is liquid chromatography-tandem mass spectrometry, often after extraction from blood, urine, or tissue. Ultraviolet detection and nuclear magnetic resonance spectroscopy are used mainly for reference material characterization. Isotope-labeled internal standards improve accuracy.
Solid material is usually kept at -20 °C, desiccated, and protected from light. Dimethyl sulfoxide stocks should be stored cold and subjected to minimal freeze-thaw cycles. Aqueous solutions are generally less stable and should be prepared fresh when possible.
Legality depends on the country and the intended use. It is not an approved medicine, and some places restrict or ban sales for human consumption. Buyers should verify local rules and product documentation before procurement.
SR9009 is a synthetic compound investigated as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is used in preclinical research on circadian rhythm and metabolism. It is not an approved drug.