This is a working overview of NR1D2, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-11-14 and is reviewed periodically as new material appears.
Analytical identification and purity assessment often use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Liquid chromatography–tandem mass spectrometry is used to detect and quantify SR9009 in biological matrices, including urine and blood, for anti-doping or pharmacokinetic studies. Nuclear magnetic resonance spectroscopy can confirm molecular structure. Stability depends on form and storage: the solid is generally more stable than solutions, and repeated freeze–thaw cycles may degrade samples. Purity is typically reported as a percentage from a certificate of analysis.
Regulatory treatment of SR9009 varies by country and context. It is not approved as a therapeutic drug by agencies such as the United States Food and Drug Administration or the European Medicines Agency. Sports authorities list it as a prohibited substance; the World Anti-Doping Agency classifies it among hormone and metabolic modulators. Legal status for personal possession or sale differs across jurisdictions, and some countries may restrict it under analog or research chemical laws. Buyers who seek verified material often rely on independent laboratory testing because online product labels may not match contents.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Common supplier description |
| Solubility | Soluble in DMSO and ethanol | Low solubility in water |
| Typical storage | −20 °C, desiccated, dark | For research samples |
| Analytical method | LC-MS/MS | Used for detection and quantification |
| Regulatory status | Prohibited in sport | WADA metabolic modulator class |
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 a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is not an approved medicine and has no established human therapeutic use. The compound appears in scientific literature as a tool for probing circadian and metabolic regulation. Online sellers often label it as a research chemical, sometimes using the nickname Stenabolic. Its chemical identity is distinct from selective androgen receptor modulators, stimulants, and peroxisome proliferator-activated receptor delta agonists. Researchers use it mainly in cell and animal experiments.
At the molecular level, SR9009 binds REV-ERBα and REV-ERBβ and alters their repressive activity on target genes. These nuclear receptors help regulate the circadian clock, lipid synthesis, glucose metabolism, and inflammatory pathways. By changing transcription, the compound can shift the timing or magnitude of downstream metabolic processes in model systems. It does not act through androgen receptors or adenosine receptors, which distinguishes it from several substances sold for athletic performance. Whether the same transcriptional changes occur in humans at tolerable exposures remains an open question because controlled human studies are lacking.
Regulatory treatment of SR9009 reflects its investigational status. The compound has no approved human therapeutic indication, and sports authorities prohibit its use. It appears on anti-doping lists as a non-approved substance or metabolic modulator, depending on the list version. Products sold online as research chemicals are not quality-controlled medicines, so their identity and purity can differ from the label. Such products may also contain unlisted compounds, which complicates both testing and safety assessment.
Scientific discussion of SR9009 often separates animal evidence from human anecdote. Rodent studies provide controlled data on endurance, metabolism, and gene expression, but they use specific strains, doses, and treatment durations. Human reports are mostly uncontrolled and cannot establish cause and effect. Open questions include oral bioavailability, tissue distribution, metabolic stability, and long-term effects. Review articles generally call for more rigorous pharmacokinetic and safety research before any clinical use could be considered.
In the name NAD+, the superscripted plus sign indicates the positive formal charge on one of its nitrogen atoms. Some NAD is converted into the coenzyme nicotinamide adenine dinucleotide phosphate (NADP), whose chemistry largely parallels that of NAD, though its predominant role is as a coenzyme in anabolic metabolism. NADP is a reducing agent in anabolic reactions like the Calvin cycle and lipid and nucleic acid syntheses. NADP exists in two forms: NADP+, the oxidized form, and NADPH, the reduced form. NADP is similar to nicotinamide adenine dinucleotide (NAD), but NADP has a phosphate group at the C-2′ position of the adenosyl.
=== Guided mode manipulations === Metamaterials can be integrated with optical waveguides to tailor guided electromagnetic waves (meta-waveguide). Subwavelength structures like metamaterials can be integrated with for instance silicon waveguides to develop and polarization beam splitters and optical couplers, adding new degrees of freedom of controlling light propagation at nanoscale for integrated photonic devices. Other applications such as integrated mode converters, polarization (de)multiplexers, structured light generation, and on-chip bio-sensors can be developed.
=== 13 January === At least 120 people were killed by shelling in western Omdurman. The Merowe Dam power station was damaged by RSF drones, causing a fire at the facility and power outages as far as Shendi, Port Sudan, Atbara and Omdurman. The SAF retook Karkaraia and Hajar al-Jawad, on the road between Dalang and Kadugli in South Kordofan, from the SPLM-N (al-Hilu). Thirteen people were killed by the SAF and allied militias in an attack on the informal settlement of Kambo Tayba in Gezira State.
Sources: en.wikipedia.org
=== Metabolic actions === Several SIRT2 deacetylation targets play important roles in metabolic homeostasis. SIRT2 inhibits adipogenesis by deacetylating FOXO1 and thus may protect against insulin resistance. SIRT2 sensitizes cells to the action of insulin by physically interacting with and activating Akt and downstream targets. SIRT2 mediates mitochondrial biogenesis by deacetylating PGC-1α, upregulates antioxidant enzyme expression by deacetylating FOXO3a, and thereby reduces ROS levels. Also, Sirt2 can reactivate the inactive G6PD by removing the acetyaltion at K403.
This helps maintain the required plasma and tissue drug levels in the body, thereby preventing any damage to the healthy tissue via the drug. The drug delivery system is highly integrated and requires various disciplines, such as chemists, biologists, and engineers, to join forces to optimize this system.
=== Croatia === Croatia finished accession (membership) negotiations on 30 June 2011 and signed the Treaty of Accession on 9 December 2011, setting it on course to become the bloc's 28th member state. A referendum on the EU accession of the Republic of Croatia was held on 22 January 2012. The EU accession referendum passed with 66.27% votes cast in support, 33.13% against the proposed joining of the EU and 0.60% invalid or blank votes; it also passed in all Croatian counties. The ratification process was concluded on 21 June 2013, and entry into force and accession of Croatia to the EU took place on 1 July 2013.
Sources: en.wikipedia.org
== Terminology == ICD-10 coding reflects both impaired-peristalsis senses and mechanical-obstruction senses of the term as modified by various adjectives. Some authors have argued for trying to reserve the term for the impaired-peristalsis senses, under which prescription certain older terms such as "gallstone ileus" and "meconium ileus", although now technically misnomers, are still accepted as correct owing to their long-established usage.
For x = 1 and y = 2 the empirical formula H2S2O7 for disulfuric (pyrosulfuric) acid is obtained. Pure disulfuric acid is a solid at room temperature, melting at 36 °C and rarely used either in the laboratory or industrial processes — although some research indicates that pure disulfuric acid has never been isolated yet.
Cell membranes are generally impermeable to charged or large, polar molecules because of the lipophilic fatty acyl chains comprising their interior. Many biologically important molecules, including a number of pharmaceutical agents, are organic weak acids that can cross the membrane in their protonated, uncharged form but not in their charged form (i.e., as the conjugate base). For this reason the activity of many drugs can be enhanced or inhibited by the use of antacids or acidic foods. The charged form, however, is often more soluble in blood and cytosol, both aqueous environments. When the extracellular environment is more acidic than the neutral pH within the cell, certain acids will exist in their neutral form and will be membrane soluble, allowing them to cross the phospholipid bilayer. Acids that lose a proton at the intracellular pH will exist in their soluble, charged form and are thus able to diffuse through the cytosol to their target. Ibuprofen, aspirin and penicillin are examples of drugs that are weak acids.
Sources: en.wikipedia.org
Legality depends on the country and the intended use. In many places it is sold as a research chemical, but sports and medicine regulations restrict it.
Detection commonly uses liquid chromatography–tandem mass spectrometry. This method can identify the compound in urine or blood at low concentrations.
Typical guidance is −20 °C, dry, and protected from light. Solutions should be aliquoted and limited freeze–thaw cycles should be used.
Its legal status depends on the country and intended use. It is not an approved medicine in major jurisdictions. In sport, it is prohibited by anti-doping rules.