If you have been reading about circadian rhythm 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 2025-12-11. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| 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 |
Identity and purity testing for SR9009 commonly uses liquid chromatography coupled with tandem mass spectrometry. This method separates the compound from matrix components and detects it by mass-to-charge transitions, providing sensitive and specific confirmation. Nuclear magnetic resonance spectroscopy can support structural identification, while high-performance liquid chromatography with ultraviolet detection may estimate purity. Because online products labeled as SR9009 may contain other substances or no active compound at all, independent verification is important in research settings. Certificates of analysis are useful but not a substitute for in-house testing.
Laboratory samples of SR9009 are typically supplied as a white to off-white powder. The compound dissolves readily in organic solvents such as dimethyl sulfoxide and ethanol, while its solubility in water is low. Because of this solubility profile, researchers often prepare concentrated stock solutions in an organic solvent before diluting them into aqueous assay buffers. Light exposure, moisture, and repeated freeze-thaw cycles can degrade many small molecules, so handling procedures usually aim to minimize these factors. Purity is commonly checked before use.
Regulatory status varies by country and intended use. Major drug agencies have not granted marketing authorization for SR9009 as a medicine, and it is not listed as a controlled substance in many jurisdictions. It is often sold as a research chemical, a category that may fall outside pharmaceutical manufacturing rules. Buyers should verify local laws and supplier documentation, including certificates of analysis. The lack of standardized quality controls raises concerns about identity, purity, and actual content in products marketed online.
In laboratory settings, SR9009 is commonly identified by its molecular structure and its interaction with REV-ERB receptors. Vendors may list it under synonyms such as Stenabolic or REV-ERB agonist, but those names do not define purity or identity. Analytical confirmation typically uses high-performance liquid chromatography with ultraviolet detection or liquid chromatography–mass spectrometry. A reference standard is needed to compare retention time and mass spectrum, because the compound can be confused with related research chemicals.
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.
Analytical methods for SR9009 typically rely on liquid chromatography coupled with tandem mass spectrometry. The technique can separate the parent compound from related substances and detect low concentrations in biological matrices. Urine and blood are common samples in anti-doping testing, while in vitro studies may use cell culture media. Rapid metabolism and low expected concentrations make method validation important for reliable identification. Exact metabolite patterns can vary by species and are not fully mapped.
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.
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.
== External links == The MEROPS online database for peptidases and their inhibitors: I04.023 alpha-2+Antiplasmin at the U.S. National Library of Medicine Medical Subject Headings (MeSH) SERPINF2+protein,+human at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Human SERPINF2 genome location and SERPINF2 gene details page in the UCSC Genome Browser.
DisplayPort cables and ports may have either a "full-size" connector or a "mini" connector. These connectors differ only in physical shape—the capabilities of DisplayPort are the same regardless of which connector is used. Using a Mini DisplayPort connector does not affect performance or feature support of the connection.
Male sex Plus three of the following in the first two years of disease: Erythrocyte sedimentation rate (ESR) >30 mm/h Unresponsive to NSAIDs Limitation of lumbar spine range of motion Sausage-like fingers or toes Oligoarthritis Onset <16 years old
The white pulp of the cupuaçu has an odour described as a mix of chocolate and pineapple and is frequently used in desserts, juices and sweets. The juice tastes primarily like pear, banana, passion fruit, and melon. Chocolate made from cupuaçu, very similar to that made from cocoa, is called cupulate.
Sources: en.wikipedia.org
Abdul Basit, senior associate fellow at the International Centre for Political Violence and Terrorism Research (ICPVTR), stressed that the concern was not the drones' sophistication, but their presence in Pakistan's capital. Taliban drones forced airspace closures and targeted deep within the country, escalating the threat both horizontally and vertically. Hammad Waleed, a research associate at Pakistan's Strategic Vision Institute, stated that while Pakistan's air defense could counter numbered drone projectiles, it would struggle against drone swarms.
On 18 October, the Brazilian government took a resolution to the UN Security Council that dealt with the Israel-Hamas conflict. In the proposal, plans to provide basic supplies to civilians in conflict situations, such as water and medicine, as well as calls for the release of Israelis held hostage by Hamas, creation a humanitarian corridor and protection of the physical integrity of civilians were some of the topics discussed; the resolution received 12 votes in favour, but was vetoed due to the opposing vote by the United States.
== Philanthropy == In 2017, Springer founded the 501(c)(3) organization Institute for Protein Innovation, which advances open antibody and protein tools for the scientific community, and funded it with a $10 million foundational grant. He also serves on the Board of Trustees of the Marine Biological Laboratory (MBL). Springer has endowed professorships at Harvard Medical School, Boston Children's Hospital, and Berkeley.
=== Aliens: Colonial Marines === Aliens: Colonial Marines was a result of Gearbox's exploration into working on licensed film properties in 2007, and was developed under license from 20th Century Fox, who held the film rights, and Sega, who held the game publishing rights to the franchise. Aliens: Colonial Marines was planned as a first-person shooter, both single-player and multiplayer, with players as members of human squads facing the franchises titular xenomorphs in settings based on the films. Gearbox did initial development on the game, but as the studio started working on Borderlands and Duke Nukem Forever, they drew developers off Aliens though still collected full payments from Sega. Sega and 2K discovered the discrepancy on Gearbox's allocation of its staff on its projects, which lead to a round of layoffs in 2008. After Gearbox released Borderlands to critical acclaim in 2009, it began work on its sequel rather than re-allocating developers to Aliens. Instead, the studio outsourced the work to third parties, including Demiurge Studios, Nerve Software, and TimeGate Studios. By 2012, Gearbox took over full development of the game as it neared its planned release in February 2013, but due to the heavily outsourced process, the game's state was haphazard, forcing Gearbox to cancel a planned beta period and rush the game through the final stages of production, certification, and distribution.
=== Halide addition === Ethylene oxide readily reacts with aqueous solutions of hydrochloric, hydrobromic, and hydroiodic acids to form halohydrins. The reaction occurs easier with the last two acids:
Sources: en.wikipedia.org
== Later life == Dayhoff's Atlas became a template for many indispensable tools in large portions of DNA or protein-related biomedical research. In spite of this significant contribution, Dayhoff was marginalized by the community of sequencers. The contract to manage GenBank (a technology directly related to her research), awarded in 1983 by the NIH, went to Walter Goad at the Los Alamos National Laboratory. The reason for this attitude was unknown, with theories ranging from sexism to a clash of values with the experimental science community. Despite the success of Dayhoff's Atlas, experimental scientists and researchers considered their sequence information very valuable and were often reluctant to submit it to such a publicly available database. During the last few years of her life, she focused on obtaining stable, adequate, long-term funding to support the maintenance and further development of her Protein Information Resource. She envisioned an online system of computer programs and databases, accessible by scientists all over the world, for identifying protein from sequence or amino acid composition data, for making predictions based on sequences, and for browsing the known information. Less than a week before she died, she submitted a proposal to the Division of Research Resources at NIH for a Protein Identification Resource. After her death, her colleagues worked to make her vision a reality, and the protein database was fully operational by the middle of 1984.
This shows that when the reaction is exothermic (ΔHo, the standard enthalpy change, is negative), then K decreases with increasing temperature, in accordance with Le Châtelier's principle. The approximation involved is that the standard enthalpy change, ΔHo, is independent of temperature, which is a good approximation only over a small temperature range. Thermodynamic arguments can be used to show that
Geckos, skinks, and some other lizards that are captured by the tail will shed part of the tail structure through a process called autotomy and thus be able to flee. The detached tail will continue to thrash, creating a deceptive sense of continued struggle and distracting the predator's attention from the fleeing prey animal. The detached tails of leopard geckos can wiggle for up to 20 minutes. The tail grows back in most species, but some, like crested geckos, lose their tails for the rest of their lives. In many species the tails are of a separate and dramatically more intense color than the rest of the body so as to encourage potential predators to strike for the tail first. In the shingleback skink and some species of geckos, the tail is short and broad and resembles the head, so that the predators may attack it rather than the more vulnerable front part. Reptiles that are capable of shedding their tails can partially regenerate them over a period of weeks. The new section will however contain cartilage rather than bone, and will never grow to the same length as the original tail. It is often also distinctly discolored compared to the rest of the body and may lack some of the external sculpting features seen in the original tail.
=== Brand names === Dutasteride is sold primarily under the brand name Avodart, but also in combination with tamsulosin under the brand names Combodart, Duodart, and Jalyn. Dutasteride is also available in India in combination with alfuzosin under the brand names Alfusin-D and Dutalfa.
=== Drug design === The Gβγ subunit plays a variety of roles in cell signalling processes and as such researchers are now examining its potential as a therapeutic drug target for the treatment of many medical conditions. However, it is recognized that there are a number of considerations to keep in mind when designing a drug which targets the Gβγ subunit:
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.
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.