A practical reference on nuclear receptor: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-03-14 and is reviewed periodically as new material appears.
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.
Because REV-ERB receptors are core clock components, SR9009 has been examined for effects on daily rhythms as well as metabolism. Research has explored whether the compound can shift or reinforce circadian gene expression in tissues such as liver and muscle. Some studies report improved metabolic markers in obese or diabetic mice, while others show context-dependent responses. Questions remain about which effects are direct, which are secondary to timing, and how they might differ across species.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic REV-ERB agonist | Small-molecule nuclear receptor ligand |
| Appearance | Off-white to pale yellow solid | Typical for research-grade powder |
| Solubility class | Soluble in DMSO; low water solubility | Common stock solutions use organic solvent |
| Typical stock solvent | Dimethyl sulfoxide | Used for laboratory assays |
| Common analytical method | HPLC with UV or mass detection | Used for identity and purity checks |
In laboratory settings, SR9009 is typically characterized by liquid chromatography–mass spectrometry (LC-MS) or high-performance liquid chromatography with ultraviolet detection (HPLC-UV). These methods can confirm identity and estimate purity, but they require reference standards for accurate quantification. Because SR9009 is not a licensed pharmaceutical, no harmonized pharmacopeial monograph exists. Laboratories often validate in-house methods for matrices such as plasma, urine, or cell culture media. Sample preparation may involve protein precipitation or liquid-liquid extraction before analysis.
Physicochemical behavior influences handling. SR9009 is described as a solid with limited aqueous solubility, so organic solvents such as dimethyl sulfoxide or ethanol are common in research stock solutions. Aqueous dilution can produce precipitates if the organic content is too low. Light, heat, and repeated freeze-thaw cycles may affect stability. Storage recommendations usually specify a desiccated freezer environment protected from light, but exact stability data depend on the formulation and matrix.
Detection in biological samples can be complicated by rapid metabolism and low circulating concentrations. Some studies report phase I and phase II metabolites, and analytical methods may need to target those species in addition to the parent compound. Immunoassays are not broadly available, so mass spectrometry remains the main confirmatory approach. For anti-doping testing, laboratories look for SR9009 and its metabolites using validated LC-MS methods. Open questions include how long metabolites remain detectable and how different routes of administration alter detection windows.
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.
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.
For long-term storage, SR9009 is typically kept as a solid at low temperature, protected from moisture and light. Desiccated conditions limit hydrolysis, while opaque containers reduce photochemical breakdown. Solutions are less stable than solids and are often stored frozen in aliquots to avoid repeated freeze-thaw cycles. Stability data are not standardized across all suppliers, so users should rely on certificate-of-analysis information when available. Degradation may appear as color change, precipitate, or decreased chromatographic purity.
Laboratory identification of SR9009 typically relies on chromatographic separation coupled to mass spectrometry, often with ultraviolet detection as a secondary check. Nuclear magnetic resonance spectroscopy can confirm molecular structure when a reference standard is available. Because many suppliers sell the compound as a research chemical, independent identity testing is important for experimental reproducibility. A single retention time is not sufficient proof of identity, especially when related compounds may be present. Purity assessments usually report a percentage based on area normalization.
SR9009 is generally described as poorly soluble in water and more soluble in organic solvents such as dimethyl sulfoxide and ethanol. Stock solutions are commonly prepared in an organic solvent before dilution into an aqueous buffer or vehicle. Precipitation can occur if the organic fraction is reduced too quickly or if the final concentration exceeds the compound's solubility limit. Sonication or gentle warming may aid dissolution in some protocols, but excessive heat can promote degradation. Container material and pH can also influence observed solubility.
Reprocessed uranium is also mainly 238U, with about as much uranium-235 as natural uranium, a comparable proportion of uranium-236, and much smaller amounts of other isotopes of uranium such as uranium-234, uranium-233, and uranium-232.
Dipeptidyl peptidase-4 inhibitors inhibit dipeptidyl peptidase-4 and thus reduce glucagon and blood glucose levels. DPP-4 inhibitors combined with metformin include a sitagliptin/metformin combination (Janumet), a saxagliptin/metformin combination (Kombiglyze XR, Komboglyze), and an alogliptin/metformin combination (Kazano, Vipdomet). Linagliptin combined with metformin hydrochloride is sold under the brand name Jentadueto. As of August 2021, linagliptin/metformin is available as a generic medicine in the US.
=== Toxicity === Today nicotine is less commonly used in agricultural insecticides, which was a main source of poisoning. More recent cases of poisoning typically appear to be in the form of Green Tobacco Sickness (GTS), accidental ingestion of tobacco or tobacco products, or ingestion of nicotine-containing plants. People who harvest or cultivate tobacco may experience GTS, a type of nicotine poisoning caused by dermal exposure to wet tobacco leaves. This occurs most commonly in young, inexperienced tobacco harvesters who do not consume tobacco. People can be exposed to nicotine in the workplace by breathing it in, skin absorption, swallowing it, or eye contact. The Occupational Safety and Health Administration (OSHA) has set the legal limit (permissible exposure limit) for nicotine exposure in the workplace as 0.5 mg/m3 skin exposure over an 8-hour workday. The US National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 0.5 mg/m3 skin exposure over an 8-hour workday. At environmental levels of 5 mg/m3, nicotine is immediately dangerous to life and health.
=== Treatment and prevention === Treatment and prevention of periwound issues are becoming increasingly important as research continues to confirm the role of periwound in wound healing. The shared objective of treatment and prevention is maintenance and/or restoration of the integrity and healthy functionality of skin surrounding the wound. Main treatment and prevention strategies include the following:
Sources: en.wikipedia.org
Louisiana governor Jeff Landry requested the deployment of the National Guard for large upcoming events: the Bayou Classic college football event November 27–29, New Year Eve and Day celebrations, and Mardi Gras celebrations in February. The New Orleans police superintendent said, "We are working together and planning their deployment." New Orleans had been the site of the January 1, 2025, terrorism attack in which 14 persons lost their lives and at least 57 persons were injured.
The nasolabial flap can be either superiorly based or inferiorly based; of which the superiorly based flap is the more practical rhinoplastic application, because it has a more versatile arc of rotation, and the donor-site scar is inconspicuous. Depending upon how the defect lay upon the nose, the flap pedicle-base can be incorporated either solely to the nasal reconstruction, or it can be divided into a second stage procedure. The blood supply for the flap pedicle are the transverse branches of the contralateral angular artery (the facial artery terminus parallel to the nose), and by a confluence of blood vessels from the angular artery and from the supraorbital artery in the medial canthus, (the angles formed by the meeting of the upper and lower eyelids). Therefore, the incisions for harvesting the nasolabial flap do not continue superiorly beyond the medial canthal tendon. The nasolabial flap is a random flap that is emplaced with the proximal (near) portion resting upon the lateral wall of the nose, and the distal (far) portion resting upon the cheek, which contains the main angular artery, and so is perfused with retrograde arterial flow.
== Problems == Problems with the electrical systems in the Warrior IFV have caused the weapon to fire without warning several times, resulting in the army issuing a safety notice. In at least one incident, this has resulted in injury to a British soldier and in others injuries to civilians. The MoD denied the problem initially. Additionally, the Challenger 2 mounting of the weapon cannot be accurately aimed using the main sight below a minimum range of 200 meters, which has led to at least one death from "friendly fire".
Sources: en.wikipedia.org
=== Design for specificity === The design of protein–protein interactions must be highly specific because proteins can interact with a large number of proteins; successful design requires selective binders. Thus, protein design algorithms must be able to distinguish between on-target (or positive design) and off-target binding (or negative design). One of the most prominent examples of design for specificity is the design of specific bZIP-binding peptides by Amy Keating and coworkers for 19 out of the 20 bZIP families; 8 of these peptides were specific for their intended partner over competing peptides. Further, positive and negative design was also used by Anderson and coworkers to predict mutations in the active site of a drug target that conferred resistance to a new drug; positive design was used to maintain wild-type activity, while negative design was used to disrupt binding of the drug. Recent computational redesign by Costas Maranas and coworkers was also capable of experimentally switching the cofactor specificity of Candida boidinii xylose reductase from NADPH to NADH.
=== Abuse === In 1924, the United States banned the sale and importation of opium for the manufacture of heroin, an opioid pain medication which was being abused. See Anti-Heroin Act of 1924. Beginning in the 1990s, prescription opioid drug abuse has been a prevalent public health issue of concern. Since 2013, with greatly increasing morbidity and deaths from overdoses of synthetic opioids, such as oxycodone, tramadol, and fentanyl, this issue has developed into a full-fledged epidemic. This has led to several other public health issues, including the spread of diseases like hepatitis C and human immunodeficiency virus (HIV). In the United States, as of 2013 more than 12 million people abused opioid drugs at least once a year. In 2010, 16,652 deaths were related to opiate overdose, in 2015 this number increased to 33,091. In September 2013, new FDA labeling guidelines for long-acting and extended-release opioids required manufacturers to remove moderate pain as use indication, reserving the drug for "pain severe enough to require daily, around-the-clock, long-term opioid treatment" however it did not restrict physicians from prescribing opioids for moderate, "as needed" usage. In January 2013, the Centers for Disease Control and Prevention (CDC) reported an illness associated with intravenous (IV) abuse of oral Opana ER (oxymorphone) in Tennessee. The syndrome resembled that of thrombotic thrombocytopenic purpura (TTP). Initial therapy included therapeutic plasma exchange, as for TTP.
=== Addiction === Selegiline has been evaluated for smoking cessation both as a monotherapy and in combination with nicotine replacement therapy in five clinical studies. However, it is limitedly or not effective for this use. It was also evaluated for treatment of cocaine dependence in one study, but was similarly not effective. Studies are mixed on whether selegiline, at MAO-B-selective doses, reduces the effects of cocaine in humans. Selegiline, also at an MAO-B-selective dosage, did not modify or potentiate the pharmacological effects of intravenous methamphetamine in a small clinical study.
== Bibliography == Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties". Chinese Physics C. 41 (3). 030001. Bibcode:2017ChPhC..41c0001A. doi:10.1088/1674-1137/41/3/030001. Beiser, A. (2003). Concepts of modern physics (6th ed.). McGraw-Hill. ISBN 978-0-07-244848-1. OCLC 48965418. Hoffman, D. C.; Ghiorso, A.; Seaborg, G. T. (2000). The Transuranium People: The Inside Story. World Scientific. ISBN 978-1-78-326244-1. Kragh, H. (2018). From Transuranic to Superheavy Elements: A Story of Dispute and Creation. Springer. ISBN 978-3-319-75813-8. Zagrebaev, Valeriy; Karpov, Alexander; Greiner, Walter (2013). "Future of superheavy element research: Which nuclei could be synthesized within the next few years?" (PDF). 11th International Conference on Nucleus-Nucleus Collisions (NN2012). Journal of Physics: Conference Series. Vol. 420. IOP Publishing. doi:10.1088/1742-6596/420/1/012001. Retrieved 20 August 2013.
Sources: en.wikipedia.org
SR9009 is a synthetic research compound that acts on REV-ERB nuclear receptors. It is not approved for human use and is sold only as a research chemical. Its effects have been studied mainly in cells and rodents.
It binds REV-ERB alpha and REV-ERB beta and changes the expression of genes tied to metabolism and circadian rhythm. These changes can affect mitochondria and energy use in animal models. The exact chain from receptor binding to physiological outcome is still being mapped.
No reliable human trials show that SR9009 improves athletic performance. Some rodent studies report endurance changes, but these results are not proof of human benefit. Its use in sport is prohibited, and quality and safety data are lacking.
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.