nuclear receptor comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-03-19. Where a claim depends on a specific study, the study is described rather than over-claimed.
SR9009 is frequently discussed alongside other REV-ERB ligands, including synthetic agonists and natural heme-related molecules. Its selectivity for REV-ERB over related nuclear receptors has been measured in binding and reporter assays, though off-target activity at higher concentrations is possible. The compound is prohibited in sport by the World Anti-Doping Agency, and it is not approved for any medical use in major jurisdictions. Products sold online may be labeled as research chemicals, and their identity and purity are not guaranteed by regulatory review.
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.
At the molecular level, SR9009 binds the ligand-binding domain of REV-ERB and strengthens recruitment of corepressor proteins such as NCoR and HDAC3. This increases repression of target genes, including Bmal1 and other clock-controlled and metabolic genes. In rodent studies, such changes have been linked to altered lipid handling, glucose metabolism, and energy expenditure. The precise chain of events between receptor binding and whole-body effects remains an active area of research. Findings in animals do not automatically translate to humans.
Laboratory studies often administer SR9009 by injection because oral absorption appears poor in rodents. Reported pharmacokinetic properties include rapid metabolism and low systemic exposure after oral dosing. Human pharmacokinetic data are sparse, so absorption, distribution, metabolism, and excretion in people are not well defined. Some research explores related REV-ERB compounds with improved drug-like properties. Regulatory approval for any REV-ERB agonist as a human medicine has not been granted to date.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ, also called NR1D1 and NR1D2. These receptors help regulate circadian rhythms and metabolic gene programs. The compound was developed for laboratory research, not as an approved therapeutic. Its identity is distinct from steroid hormones and selective androgen receptor modulators. Scientific interest centers on how REV-ERB activation changes gene expression in cells and animal models.
| Property | Value | Notes |
|---|---|---|
| Common name | SR9009 | Also marketed informally as Stenabolic |
| Chemical class | Synthetic REV-ERB agonist | Binds REV-ERBα and REV-ERBβ |
| Molecular formula | C24H30ClN3O4S | Approximate molecular weight 492 g/mol |
| CAS Registry Number | 1379686-30-2 | Identifier for the parent compound |
| Regulatory status | Not approved for human use | Prohibited in sport by WADA |
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is not a steroid, peptide, or natural hormone. In scientific literature, it appears under the code SR9009 and in non-scientific contexts as Stenabolic. The compound was identified through chemical screening efforts aimed at targeting circadian clock components. Its status remains investigational, and no regulatory agency has approved it as a human medicine.
REV-ERB proteins help regulate daily cycles in gene expression, including genes tied to lipid and glucose metabolism. SR9009 binds these receptors and alters their activity in cell and animal experiments. Consequences observed in rodents include changes in skeletal muscle oxidative capacity, blood lipid levels, and exercise performance. The precise chain from receptor occupancy to whole-body effects is still an active area of study. Human responses cannot be assumed from rodent data.
Handling practices for SR9009 focus on minimizing degradation and contamination. The solid is generally stored desiccated at or below -20 °C, protected from light and moisture. Stock solutions are often prepared in dimethyl sulfoxide or ethanol, then aliquoted to avoid repeated freeze–thaw cycles. Aqueous solubility is low, so formulations for animal studies may require cosolvents or suspending agents. Personnel should follow institutional chemical safety procedures, because toxicological data for humans are incomplete.
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.
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.
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.
==== Thick-client ==== A thick-client LIMS is a more traditional client/server architecture, with some of the system residing on the computer or workstation of the user (the client) and the rest on the server. The LIMS software is installed on the client computer, which does all of the data processing. Later it passes information to the server, which has the primary purpose of data storage. Most changes, upgrades, and other modifications will happen on the client side. This was one of the first architectures implemented into a LIMS, having the advantage of providing higher processing speeds (because processing is done on the client and not the server). Additionally, thick-client systems have also provided more interactivity and customization, though often at a greater learning curve. The disadvantages of client-side LIMS include the need for more robust client computers and more time-consuming upgrades, as well as a lack of base functionality through a web browser. The thick-client LIMS can become web-enabled through an add-on component. Although there is a claim of improved security through the use of a thick-client LIMS, this is based on the misconception that "only users with the client application installed on their PC can access server side information". This secrecy-of-design reliance is known as security through obscurity and ignores an adversary's ability to mimic client-server interaction through, for example, reverse engineering, network traffic interception, or simply purchasing a thick-client license.
where Ep is potential energy, q is the charge of the particle, and U is the electric potential difference (also known as voltage). When the charged particle is accelerated into time-of-flight tube (TOF tube or flight tube) by the voltage U, its potential energy is converted to kinetic energy. The kinetic energy of any mass is:
== Natural occurrence == Myristicin can be found in the essential oil of nutmeg, black pepper, kawakawa, and many members of the Umbelliferae family, including anise, carrots, parsley, celery, dill, and parsnip. Trace amounts have also been isolated from a variety of plant species including Ridolfia segetum (harvest fennel), species of the Oenanthe genus (water dropworts), some species of the Lamiaceae family (mint family), Cinnamomum glanduliferum (Nepal camphor tree), and Piper mullesua ("Hill Pepper"). Depending on the conditions of growth and storage of the plant, a high quality nutmeg (Myristica fragrans) seed can contain up to 13 mg of myristicin per 1 gram.
=== Dietary === In the United States, many people's diets are excessively high in calories, often due to fast food and sugary beverages. Individuals with obesity may consume more calories before feeling full, experience hunger more quickly, or eat in response to stress or anxiety. Per the USDA's Dietary Guidelines for Americans, 2020-2025, most Americans do not follow a healthy dietary pattern. Few individuals being tested for nutrient levels would be able to meet them without the use of fortification or enrichment. Americans eat an abundance of fast food. 36.6% of adults consume fast food on a given day and 2 out of 3 people consume fast food at least once a week. While the negative effects of fast food, such as lack of nutritional value and high amounts of calories, are widely known, fast food remains popular for its convenience, specifically because it is time-efficient and cheap. Quantity of food consumption plays an important role as well. A study shows a significant increase in food portion sizes of marketplace products since the 1970s that exceed the federal standards for dietary guidance. Reasons for this increase include the expansion of the food industry since the seventies, marketing strategies, and customer demand. Extreme differences in portion sizes between the same menu items of the same franchises have also been observed. In some instances, American food portion sizes are as much as double the size of their British counterparts.
Sources: en.wikipedia.org
Librarian Ainsworth Rand Spofford, who directed the Library of Congress from 1865 to 1897, built broad bipartisan support to develop it as a national library and a legislative resource. He was aided by expansion of the federal government after the war and a favorable political climate. He began comprehensively collecting Americana and American literature, led the construction of a new building to house the library, and transformed the librarian of Congress position into one of strength and independence. Between 1865 and 1870, Congress appropriated funds for the construction of the Thomas Jefferson Building, placed all copyright registration and deposit activities under the library's control, and restored the international book exchange. The library also acquired the vast libraries of the Smithsonian and of historian Peter Force, strengthening its scientific and Americana collections significantly. By 1876, the Library of Congress had 300,000 volumes; it was tied with the Boston Public Library as the nation's largest library. It moved from the Capitol building to its new headquarters in 1897 with more than 840,000 volumes, 40 percent of which had been acquired through copyright deposit. A year before the library's relocation, the Joint Library Committee held hearings to assess the condition of the library and plan for its future growth and possible reorganization. Spofford and six experts sent by the American Library Association testified that the library should continue its expansion to become a true national library.
Replacing natural polyunsaturated fatty acids (PUFA) with deuterated PUFA (dPUFA), which have deuterium in place of the bis-allylic hydrogens, can prevent cell death induced by erastin or RSL3. These deuterated PUFAs effectively inhibit ferroptosis and various chronic degenerative diseases associated with ferroptosis. Live-cell imaging has been used to observe the morphological changes that cells undergo during ferroptosis. Initially the cell contracts and then begins to swell. Perinuclear lipid assembly is observed immediately before ferroptosis occurs. After the process is complete, lipid droplets are redistributed throughout the cell (see GIF on right side).
=== Small RNA molecules regulate gene expression by post-transcriptional gene silencing === Another previously unknown mechanism by which RNA molecules are involved in genetic regulation was discovered in the 1990s. Small RNA molecules termed microRNA (miRNA) and small interfering RNA (siRNA) are abundant in eukaryotic cells and exert post-transcriptional control over mRNA expression. They function by binding to specific sites within the mRNA and inducing cleavage of the mRNA via a specific silencing-associated RNA degradation pathway.
Sources: en.wikipedia.org
On 15 September 2022, during a speech commemorating El Salvador's 201st anniversary of independence, Bukele announced that he would run for re-election in 2024. According to Bukele, "developed countries have re-election, and thanks to the new configuration of the democratic institution of our country, now El Salvador will too". Constitutional lawyers criticized his announcement, saying that presidential re-election violates "at least" four articles of the El Salvador constitution.
As an expansion pack for Half-Life, Opposing Force is a first-person shooter. The overall gameplay of Opposing Force does not significantly differ from that of Half-Life. Players navigate through levels, fight hostile non-player characters and solve a variety of puzzles to advance. The game continues Half-Life's methods of an unbroken narrative. The player sees everything through the first person perspective of the protagonist and remains in control of the player character for almost all of the game. Story events are conveyed through the use of scripted sequences rather than cut scenes. Progress through the world is continuous; although the game is divided up into chapters, the only significant pauses are when the game needs to load the next part of an environment. Opposing Force also features an extended multiplayer, incorporating the various new environments and weapons into the original deathmatch mode used in Half-Life. After release, a new capture the flag mode with additional levels, items and powerups, was created by Gearbox. For the most part the player battles through the single-player game alone, but is occasionally assisted by friendly non-player characters. Security guards and scientists will occasionally help the player in reaching new areas and convey relevant plot information. However, Opposing Force also features fellow U.S. Marines who will assist the player in combat to a far greater degree than security guards.
== Research == Oxyntomodulin could be a potential candidate for treating obesity because of its ability to suppress appetite. In a 4 week study, healthy overweight and obese volunteers were given either saline or oxyntomodulin injections. Their body weight, energy intake, and the levels of adipose hormones were taken prior to the treatment. The volunteers maintained their usual diets and daily activities and self-administered the injections three times daily, 30 minutes before their meals. In the course of 4 weeks, volunteers treated with oxyntomodulin injections had an average weight loss of 2.3±0.4 kg compared to those treated with saline who had an average of 0.5±0.5 kg, indicating oxyntomodulin was successful in weight loss.
A diplomatic crisis began in 2025 when the Donald Trump's second presidency of the United States administration sought to annex Greenland, an autonomous territory of the Danish Realm—a treaty ally of the United States and co-member of NATO, and a member of the European Union (EU). The crisis intensified in early 2026 when Trump refused to rule out the use of military force for this annexation and threatened a 25% import tax on goods from several European nations unless Denmark ceded the territory to the United States. Denmark's refusal was supported by the EU and several other NATO members, reigniting earlier concerns of a US–EU trade war. Within weeks, Trump backed down, pledging not to use force or tariffs to annex Greenland. Trump had tried to purchase Greenland during his first presidency. After his 2024 re-election, in January 2026, he said "it may be a choice" whether to preserve NATO or seize Greenland, and in Dear Jonas, a letter leaked by Norwegian Prime Minister Jonas Gahr Støre, Trump had said that he "no longer [felt] an obligation to think purely of Peace" after not receiving the Nobel Peace Prize. A report by the Danish Defence Intelligence Service mentioned the United States as a potential threat to national security for the first time in its history, and Danish officials raised concerns about reports that Director of National Intelligence Tulsi Gabbard had assigned agents to spy on Greenland. The Greenlandic and Danish prime ministers rejected any American takeover, saying they would defend Greenland in the event of an attack.
Sources: en.wikipedia.org
SR9009 is a synthetic research compound that binds and modulates the nuclear receptors REV-ERBα and REV-ERBβ. It is used in laboratory studies of circadian biology and metabolism, not as an approved medicine. It is also known by the informal name Stenabolic.
No. SR9009 has not been approved as a therapeutic drug in the United States, European Union, or other major markets. Human safety and efficacy data are very limited. Its presence in consumer products does not imply regulatory approval.
The World Anti-Doping Agency lists SR9009 as a prohibited substance because it can alter gene expression and metabolic pathways relevant to performance. The ban applies at all times, not only during competition. Detection relies on laboratory methods such as mass spectrometry.
SR9009 is a synthetic research compound that activates the REV-ERBα and REV-ERBβ nuclear receptors. It is not an approved drug and has no established human therapeutic use. Most published biological data come from cell and rodent studies.