If you have been reading about NR1D2 and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-08-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
SR9009 is a synthetic small molecule developed as an agonist of the nuclear receptors REV-ERBα (NR1D1) and REV-ERBβ (NR1D2). These receptors help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, SR9009 alters transcription of genes involved in lipid metabolism, inflammation, and mitochondrial function. It is not an approved medicine, and its pharmacological profile in humans remains largely uncharacterized. The compound is frequently discussed in the context of circadian biology and metabolic research rather than clinical use.
Preclinical reports have linked SR9009 to improved endurance and altered energy expenditure in rodents. Such findings have prompted interest in whether REV-ERB activation can influence skeletal muscle metabolism. However, the reported effects depend on dose, route, and experimental model, and replication across laboratories is limited. Human trials have not established comparable outcomes, so claims about exercise performance remain speculative. The absence of controlled human data is a central limitation in interpreting these observations.
The mechanism of action involves binding to REV-ERB receptors and recruiting corepressor complexes, which represses target gene transcription. This contrasts with many nuclear receptor agonists that activate transcription. Downstream effects may include changes in autophagy, mitochondrial biogenesis, and lipid handling, but the precise pathways remain an active area of study. Whether these molecular events translate into meaningful physiological effects in humans is unresolved. Most evidence comes from cultured cells and rodent models rather than human participants.
SR9009 is supplied as a solid research chemical, often in milligram quantities. Laboratories typically weigh it in a controlled environment because fine powders can disperse. Stock solutions are commonly prepared in dimethyl sulfoxide and stored in small aliquots to reduce freeze-thaw cycles. Personal protective equipment and chemical fume hoods are standard when handling unknown or potent compounds. These practices address laboratory safety rather than human use.
Identity and purity of SR9009 samples are usually checked with chromatographic and spectrometric methods. High-performance liquid chromatography can separate the compound from related impurities, while mass spectrometry provides molecular mass confirmation. Nuclear magnetic resonance spectroscopy may be used for structural verification in research settings. No single method proves biological activity, and certificates of analysis should be reviewed alongside raw data. Independent testing is often needed because online products vary widely.
SR9009 stability depends on temperature, moisture, light, and solvent. Solid material is generally kept cool and dry, while solutions may require protection from repeated warming and cooling. Degradation can appear as color changes, precipitate, or new chromatographic peaks. Researchers should follow supplier instructions and their own stability data. Long-term storage conditions for human use have not been established because the compound lacks approved clinical formulation.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic REV-ERB agonist | Small molecule; not a steroid or peptide. |
| Primary targets | NR1D1 and NR1D2 | Also known as REV-ERBα and REV-ERBβ. |
| Studied routes | Intraperitoneal in rodents | Oral bioavailability in humans is not established. |
| Human approval | No approved therapeutic indication | No recognized clinical use. |
| Key uncertainty | Human physiological effects | Preclinical findings may not translate. |
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.
SR9009 is not approved as a medicine by major regulatory agencies. It is commonly sold as a research chemical, a category that may fall outside customary drug approval and quality rules. In sports, the World Anti-Doping Agency lists SR9009 as a prohibited substance. Athletes who use it can face sanctions if it is detected in a sample. Legal status varies by country, and importation may be restricted. Enforcement practices differ across borders.
Detection of SR9009 in biological samples usually employs liquid chromatography coupled with tandem mass spectrometry. This method can identify the parent compound and sometimes metabolites in urine or blood. Because exposure can be low and clearance may be rapid, sample timing and limits of detection matter. Laboratories validate assays for sensitivity and specificity. Results are interpreted alongside chain-of-custody and quality-control records. Urine is the common matrix for anti-doping analysis, while blood may be used in research settings.
Handling recommendations for SR9009 in a laboratory setting include storing the solid at low temperature, protected from light and moisture. The compound is often dissolved in dimethyl sulfoxide or ethanol for experiments. Solutions should be prepared with appropriate personal protective equipment and disposed of according to local rules. Stability data for long-term storage are limited, so stock solutions are typically kept cold and used within defined periods. Records of preparation date and concentration support reproducibility.
Israel and the US asserted that the ceasefire did not include Lebanon, contradicting the Pakistani mediators and Iran. Hezbollah said it had halted attacks on Israel and on Israeli soldiers in Lebanon. Despite the ceasefire, Israel launched "Operation Eternal Darkness", which, according to Israeli forces, included targeting all Hezbollah's command and control centers in southern Lebanon, Beirut and the Beqaa Valley. Local observers disputed this, saying the attacks were not targeted. These were the largest attacks since the start of the war, killing at least 357 people and injuring more than 1,200. In Beirut alone, 92 people were killed and at least 740 injured. In response, Iran threatened to attack Israel "if the aggressions against dear Lebanon are not brought to an immediate end". Iran paused Strait of Hormuz traffic over Israeli attacks in Lebanon. Hezbollah claimed responsibility for launching rockets towards northern Israel as a response to "ceasefire violations". On 11 April, Trump said that American forces had started "clearing" the Strait of Hormuz. Iran claimed that an American ship on its way to the strait turned back after being warned. The Wall Street Journal reported US Navy destroyers entered the strait for the first time since the war began. The Iranian government reportedly threatened to attack the ships, accusing the US of a ceasefire violation. US Central Command said the ships were minesweeping.
(2026) study the morphology of hominin limb bones from the Salawusu site (China), finding no evidence of diagnostic features of the Neanderthal lineage, and reporting morphological evidence consistent with affinities with modern humans. Li et al. (2026) report evidence from the study of the palynological record from the East China Sea continental shelf spanning the past 71,000 years indicative of presence of a cool, dry temperate grassland biome during the lowstand intervals (including the Last Glacial Maximum), as well as evidence of presence of an open-forest landscape during the milder conditions of the Marine Isotope Stage 3, and interpret their findings as supporting the interpretation of the exposed East China Sea continental shelf as a habitat facilitating the initial dispersal of early modern humans into East Asia. Zhang et al. (2026) study the features of stone tools from the Nwya Devu site (China), reporting evidence of differences from stone tool assemblages from northern Initial Upper Paleolithic sites, and interpret tools from the Nwya Devu site as either representing a regional variant of Initial Upper Paleolithic technology or resulting from a separate dispersal of blade technologies into East Asia. Totsuka et al. (2026) reconstruct the chronology of early Upper Paleolithic sites in Japan, and report evidence of rapid increase in the number of sites between 36,000 and 34,000 years ago that was likely linked to growth of the human population size. Oktaviana et al.
Further contributions of Gil-Av and associates are concerned with the use of chiral mobile phase additives (CMPAs) in liquid chromatography (LC), enantiomeric separation of helicenes by supramolecular LC, the temperature-dependent reversal of enantioselectivity by enthalpy-entropy compensation and non-linear effects leading to enantiomeric enrichment during chromatography on achiral stationary phases.
Sources: en.wikipedia.org
The human NDUFB4 gene codes for a subunit of Complex I of the respiratory chain, which transfers electrons from NADH to ubiquinone. However, NDUFB4 is an accessory subunit of the complex that is believed not to be involved in catalysis. Mammalian complex I is composed of 45 different subunits. It locates at the mitochondrial inner membrane. This protein complex has NADH dehydrogenase activity and oxidoreductase activity. It transfers electrons from NADH to the respiratory chain. The immediate electron acceptor for the enzyme is believed to be ubiquinone. Initially, NADH binds to Complex I and transfers two electrons to the isoalloxazine ring of the flavin mononucleotide (FMN) prosthetic arm to form FMNH2. The electrons are transferred through a series of iron-sulfur (Fe-S) clusters in the prosthetic arm and finally to coenzyme Q10 (CoQ), which is reduced to ubiquinol (CoQH2). The flow of electrons changes the redox state of the protein, resulting in a conformational change and pK shift of the ionizable side chain, which pumps four hydrogen ions out of the mitochondrial matrix.
The purpose of radiological emergency preparedness is to protect people from the effects of radiation exposure after a nuclear accident or bomb. Evacuation is the most effective protective measure. However, if evacuation is impossible or even uncertain, then local fallout shelters and other measures provide the best protection.
1 by the Minister, after consultation with such bodies representative of those interests as he may think fit, to represent the interests of persons (other than the British Transport Commission and any Executive) who are holders of A or B licences (within the meaning of Part IV of this Act) carrying on business within the London Traffic Area:† 1 by the Minister, after consultation with such bodies representative of those interests as he may think fit, to represent the interests of persons who are holders of C licences (within the meaning of Part IV of this Act) carrying on business within the London Traffic Area:† 1 by the Minister, after consultation with such bodies representative of those interests as he may think fit, to represent the interests of persons (other than the British Transport Commission and any Executive) who are the holders of licences authorising them to operate public service vehicles within the London Traffic Area: 1 by the Minister, after consultation with such bodies representative of those interests as he may think fit, to represent the interests of persons (other than the British Transport Commission and any Executive) providing or using horse-drawn road vehicles within the London Traffic Area. 1 by the Minister, after consultation with such bodies representative of those interests as he may think fit, to represent the interests of the taxi-cab industry within the London Traffic Area.
When a significant region around a crack tip has undergone plastic deformation, other approaches can be used to determine the possibility of further crack extension and the direction of crack growth and branching. A simple technique that is easily incorporated into numerical calculations is the cohesive zone model method which is based on concepts proposed independently by Barenblatt and Dugdale in the early 1960s. The relationship between the Dugdale-Barenblatt models and Griffith's theory was first discussed by Willis in 1967. The equivalence of the two approaches in the context of brittle fracture was shown by Rice in 1968.
Sources: en.wikipedia.org
== Genetic coding == In 1993, the gene sequence of CK1δ was initially described by Graves et al. who isolated the cDNA from testicles of rats. After sequencing and characterization of the gene, the construct was described as a 1284 nucleotide sequence resulting in a protein consisting of 428 amino acids after transcription. The molecular weight of the according protein was published as 49 kDa. Three years later, the same gene was identified in humans. The human CSNK1D contains 1245 nucleotides and is transcribed into a protein consisting of 415 amino acids. Ever since, CK1δ was investigated and described in various animals, plants, as well as parasites (Caenorhabditis elegans, 1998; Drosophila melanogaster, 1998; Mus musculus, 2002; Xenopus laevis, 2002.)
=== Epstein–Barr virus === Spironolactone has been found to block Epstein–Barr virus (EBV) production and that of other human herpesviruses by inhibiting the function of an EBV protein SM, which is essential for infectious virus production. This effect of spironolactone was determined to be independent of its antimineralocorticoid actions.
He also accused the Russian military of laying mines targeting his personnel as they retreated. The governor of Russia's Bryansk Oblast claimed that Ukrainian forces shelled a village along the international border, destroying a house. Two people were reportedly killed and two others injured when Ukrainian forces shelled a road in Maslova Pristan, Belgorod Oblast, while the Freedom of Russia Legion claimed responsibility for an attack on the village of Novaya Tavolzhanka and claimed that Russian government forces had killed two civilians after mistaking their vehicle for that of the legion. Long-range drones hit two towns in Smolensk Oblast, while an explosion was reported in a forest in Kaluga Oblast. Officials claimed that buildings were damaged in Bryansk and Kursk by Ukrainian shelling and a nighttime drone attack. Russian Deputy Prime Minister Viktoria Abramchenko said Russia sowed winter crops for the year's harvest in the territories it annexed during the invasion, providing state support worth 3 billion rubles ($37.1 million) to farmers in the occupied regions and harvesting grain, beans and rapeseed on 1.3 million hectares. The Chairman of the US Joint Chiefs of Staff General Mark Milley announced that Ukrainian soldiers had begun training in the use of M1 Abrams tanks pledged to Ukraine by the West. The United States approached Japan for supplies of TNT to be used in 155 mm caliber shells for Ukraine. According to Reuters, the Japanese government allowed the US government to purchase industrial TNT as it is not a military product.
Sources: en.wikipedia.org
It is a synthetic compound that acts as an agonist at REV-ERBα and REV-ERBβ. It is used mainly as a research chemical to study circadian and metabolic pathways. It is not approved for human therapeutic use.
REV-ERB receptors generally repress transcription when bound by natural heme. SR9009 is described as an agonist that enhances this repressive activity. The result is altered expression of clock and metabolic genes.
Published controlled human trials are lacking. Some sources cite limited or unofficial reports, but these do not establish safety or efficacy. Claims about human performance effects remain unverified.
Laboratories commonly use liquid chromatography coupled with mass spectrometry to detect SR9009. The method can identify the compound and estimate concentration in a sample. Detection limits depend on the matrix and instrument.