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.
Last reviewed on 2026-01-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Stability depends on physical form, temperature, light exposure, and solvent. Solid SR9009 is generally stored cold and dry, with protection from light to limit degradation. Dimethyl sulfoxide stocks are common for laboratory work, but repeated freeze-thaw cycles can reduce compound integrity. Aqueous solutions may be less stable than organic stocks, and the ethyl ester in the structure can be susceptible to hydrolysis under certain conditions. Researchers typically validate storage conditions and recheck purity before quantitative experiments, especially when using archived 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.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Not approved for human use | Research-use-only status in many markets |
| WADA status | Prohibited in sport | Generally listed as a non-approved substance |
| Detection technique | LC-MS/MS | Common for urine and blood analysis |
| Common alias | Stenabolic | Informal market nickname, not a pharmacopoeial name |
| Purity check | HPLC or LC-UV | Independent certificate of analysis is typical |
SR9009 is a synthetic small molecule that acts on the nuclear receptors REV-ERBα and REV-ERBβ. These receptors are part of the circadian clock machinery and normally repress transcription of certain target genes. In laboratory research, SR9009 is used as a chemical tool to study how REV-ERB activity influences metabolism, inflammation, and daily biological rhythms. The compound is not an approved medicine, and its effects in humans remain largely uncharacterized. It is often described as an investigational agent rather than a therapeutic product.
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 a synthetic small molecule studied as a REV-ERB agonist. REV-ERBα and REV-ERBβ are nuclear receptors that help regulate circadian rhythms and metabolic gene expression. The compound was identified in academic screening efforts to find synthetic ligands for these receptors. In cell and animal studies, SR9009 alters transcription of genes involved in lipid and glucose metabolism, and it can shift circadian behavior. It is not an approved therapeutic agent.
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.
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.
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.
In rail transport, the Single European Railway Directive 2012 requires that ownership of tracks and operating companies are separated to prevent conflicts of interest and pricing, particularly to ensure that trains can run from one member state to another. Most European railways are publicly owned, and each train enterprise must have separate accounts and member states should run railways 'at the lowest possible cost for the quality of service required'. The Rail Passenger Rights Regulation 2007 article 17 states that 25% of a ticket price should be refunded if there is a one-hour delay, and 50% over two hours, with a threshold of €4 to claim. Passengers have a right to take bicycles on trains where they are not overcrowded, there must be clear information on tickets, and there are rights to make reservations. Finally, in air transport, under the Flight Compensation Regulation (EC) No 261/2004 there is a minimum right of €250 compensation for 2 hour delay on 1500 km flight, €400 compensation for 3 hour delay or more on a 1500–3500 km flight, and €600 for 4 hours in flights over 3500 km flight, plus the right to refreshments, hotels, and alternative transport. There are not yet duties on airline companies to invest in research for clean fuels, and eliminate unnecessary flight paths when clean land transport alternatives (such as high-speed rail) exist. Finally, the 'right to housing assistance' is a basic part of EU law. House prices are affected by monetary policy (above), but otherwise the EU's involvement is so far limited to minimal environmental standards.
National Security Council spokesman John Kirby responded by accusing Lula of "parroting Russian and Chinese propaganda", describing his comments as "simply misguided" and "suggesting the United States and Europe are somehow not interested in peace, or that we share responsibility for the war." On 19 May 2023, Lula said he was "upset" after Ukrainian president Volodymyr Zelesnkyy did not attend a meeting between both on the sidelines of the G7 Summit in Hiroshima. On 22 May, Danish foreign minister Lars Løkke Rasmussen said that Denmark was interested in hosting a summit aimed at "finding peace between Ukraine and Russia". but "it is necessary to build interest and involvement from countries like India, Brazil and China." In September 2023, Lula and Ukrainian president Volodymyr Zelenskyy met on the sidelines of the 78th United National General Assembly (UNGA), in New York; Lula pledged to maintain an open dialogue between their countries to end the war.
== Research == Aceclidine has been a subject of clinical and pharmacological research since the 1960s. Early studies in the 1970s compared its efficacy for glaucoma to that of pilocarpine, finding it produced a similar reduction in intraocular pressure with a lesser effect on accommodation. Research in the 1980s on its optical isomers determined the (+)-enantiomer was the primary source of its cholinergic activity. In the 2010s, research refocused on aceclidine as a potential treatment for presbyopia due to its pupil-selective mechanism. Under the development code PRX-100, Lenz Therapeutics conducted the Clarity 1, 2, and 3 clinical trials. Clarity 1 and 2 were Phase III trials that evaluated aceclidine 1.44 % in adults with presbyopia and met all primary and secondary endpoints for improving near visual acuity. Clarity 3 was a long-term study that confirmed the drug's safety and tolerability over a six-month period. The results of these trials formed the basis for its FDA approval in 2025.
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 appear in the genetic code of life. Amino acids can be classified according to the locations of the core structural functional groups (alpha- (α-), beta- (β-), gamma- (γ-) amino acids, etc.); other categories relate to polarity, ionization, and side-chain group type (aliphatic, acyclic, aromatic, polar, etc.). In the form of proteins, amino-acid residues form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling life on Earth and its emergence. Amino acids are formally named by the IUPAC-IUBMB Joint Commission on Biochemical Nomenclature in terms of the fictitious "neutral" structure shown in the illustration. For example, the systematic name of alanine is 2-aminopropanoic acid, based on the formula CH3−CH(NH2)−COOH. The Commission justified this approach as follows:
Sources: en.wikipedia.org
== Formation and decay == The sum of the atomic mass of the two atoms produced by the fission of one fissile atom is always less than the atomic mass of the original atom. This is because some of the mass is lost as free neutrons, and once kinetic energy of the fission products has been removed (i.e., the products have been cooled to extract the heat provided by the reaction), then the mass associated with this energy is lost to the system also, and thus appears to be "missing" from the cooled fission products. Since the nuclei that can readily undergo fission are particularly neutron-rich (e.g. 61% of the nucleons in uranium-235 are neutrons), the initial fission products are often more neutron-rich than stable nuclei of the same mass as the fission product (e.g. stable zirconium-90 is 56% neutrons compared to unstable strontium-90 at 58%). The initial fission products therefore may be unstable and typically undergo beta decay to move towards a stable configuration, converting a neutron to a proton with each beta emission. (Most fission products do not decay via alpha decay.) A few neutron-rich and short-lived initial fission products decay by ordinary beta decay (this is the source of perceptible half-life, typically a few tenths of a second to a few seconds), followed by immediate emission of a neutron by the excited daughter-product. This process is the source of so-called delayed neutrons, which play an important role in control of a nuclear reactor. The first beta decays are rapid and may release high energy beta particles or gamma radiation.
== Medical uses == Lobeglitazone is used to assist regulation of blood glucose level of diabetes mellitus type 2 patients. It can be used alone or in combination with metformin. Lobeglitazone was approved by the Ministry of Food and Drug Safety (Korea) in 2013, and the postmarketing surveillance is on progress until 2019.
== Diet == There is no one food or nutrient capable of providing adequate bone health on its own. Instead, a balanced diet sufficient in fruits and vegetables for their vitamins, minerals, and alkalinizing substrates is thought to be most beneficial. High protein diets supply larger amounts of amino acids that could be degraded to acidic compounds. Protein consumption above the Recommended Dietary Allowance is also known to be beneficial to calcium utilization. Overall, it is understood that high-protein diets have a net benefit for bone health because changes in IGF-I and PTH concentrations outweigh the negative effects of metabolic acid production. The source of protein, plant or animal, does not matter in terms of acid produced from amino acid metabolism. Any differences in methionine and cysteine content is not significant to affect the overall potential renal acid load (PRAL) of the food. In addition to their acid precursor protein content, plants also contain significant amounts of base precursors. Potassium bicarbonate, a basic salt, is produced via the metabolism of other organic potassium salts: citrate, malate, and gluconate, which are substantial in plants. The discrepancy observed in PRAL is accounted for by differences in base precursor content.
Sources: en.wikipedia.org
Many new features for tandem mass analysis were gradually revealed by using the digital ion trap. Ions can be selectively removed from the ion trap by boundary ejection simply by varying the duty cycle of the digital waveform, instead of applying the conventional "resolving DC" voltage. Since rectangular waveforms are employed in the DIT, electrons can be injected into the trap during one of the voltage level without being accelerated up by the varying electric field. This enabled Electron-capture dissociation, which needs very low energy electron beam to interact with the trapped ions, achieved in the digital ion trap, without assistance of a magnetic field. Other forms of digital ion trap were also developed, including the linear ion trap constructed using printed circuit boards and the rods structure linear ion guide/trap. Two sets of switch circuitry were normally used to generate 2 phases of rectangular pulse waveform for two pairs of rods in case of the linear digital ion trap.
In 2015, they collaborated with the electronics company HTC to develop the HTC Vive, a virtual reality headset released in 2016. Valve's president, Gabe Newell, aimed for Valve to become more like Nintendo, which develops games in tandem with hardware, allowing them to create innovative games such as Super Mario 64 (1996). In 2016, Valve released The Lab, a collection of VR minigames, and recognized that many players wanted a more ambitious VR AAA game. Walker wondered if they could develop a VR "killer app" equivalent to the influential FPS Doom in 1993.
In boosted fission weapons a mix of 2H and 3H is heated until there is thermonuclear fusion to produce helium and free neutrons. These fast neutrons then cause further fission, creating "boosting". In 1951, in Operation Greenhouse, a prototype named George, validated the proof of concept for such a weapon. However, the first true boosted fission bomb, Greenhouse Item, was successfully tested in 1952, giving a 45.5-kiloton yield, nearly double that of an unboosted bomb. The United States stopped producing tritium in nuclear reactors in 1988, but nuclear tests in the 1950s added large spikes of radionuclides to the air, especially carbon-14 and 3H. This complicated measurements for geologists using carbon dating. However, some oceanographers benefited from the 3H increase, using the signal in the water to trace physical mixing of water masses.
Sources: en.wikipedia.org
Legality depends on the country and the intended use. In many places it is not approved as a medicine and may be sold only as a research chemical. Importation or possession can be restricted, and sports organizations prohibit it.
Anti-doping laboratories typically use LC-MS/MS to detect SR9009 or its metabolites in urine or blood. The exact assay depends on the laboratory and the testing program. Detection can be challenging because the compound may be rapidly metabolized and present at low levels.
Stenabolic is an informal nickname used in online fitness and research-chemical markets, not an official drug name. It likely references reported effects on endurance in rodent studies. The nickname does not imply approval or proven human benefit.
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.