Everything below concerns circadian rhythm. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-01-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Most published work on SR9009 consists of preclinical studies. It is widely sold as a research chemical, a category that does not imply safety, efficacy, or pharmaceutical-grade quality. Sports anti-doping organizations have listed SR9009 as a prohibited substance, and its presence in an athlete sample can lead to sanctions. Legal status differs by country; in several jurisdictions it is not approved for human consumption and may be treated as an unapproved new drug.
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.
| Property | Value | Notes |
|---|---|---|
| Synonyms | SR9009; Stenabolic | Stenabolic is an informal name |
| Common form | Crystalline powder | Supplied in milligram to gram quantities |
| Long-term storage | -20 °C, desiccated, protected from light | Reduces degradation |
| Detection technique | LC-MS/MS | Common in anti-doping and research analysis |
| Regulatory status | Prohibited in sport by WADA | Not approved for human therapeutic use |
Quality control for research materials includes identity confirmation by nuclear magnetic resonance and purity assessment by high-performance liquid chromatography. Mass spectrometry provides molecular weight confirmation and can detect related impurities. Purchasers should request a certificate of analysis that lists lot-specific data. Online products advertised for human use often lack such documentation. Distinguishing legitimate research material from mislabeled or contaminated samples is a recurring challenge in independent testing, and independent laboratories may use orthogonal methods to verify identity.
Detection of SR9009 in biological samples usually relies on liquid chromatography coupled to tandem mass spectrometry. This approach separates the compound from matrix components and identifies it by mass transitions. Because SR9009 can undergo metabolism, laboratories often look for both parent drug and specific metabolites. Sample preparation may involve protein precipitation or solid-phase extraction. Method validation examines sensitivity, carryover, and interference from related substances, and reference standards are required for accurate calibration.
Pharmacokinetic data for SR9009 are limited in published literature. Some reports indicate low oral bioavailability and rapid clearance in animals, which complicates interpretation of exposure and effect. Researchers often use injected routes in preclinical work to achieve measurable systemic levels. Analytical studies rely on mass spectrometry to detect the parent compound and its metabolites. Questions about tissue distribution, active metabolites, and long-term consequences remain open. Species differences in metabolism can affect observed half-life and target engagement.
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 and metabolic gene expression. In laboratory experiments, SR9009 binds these receptors and alters transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. It is not a naturally occurring compound and has no approved therapeutic use. Research interest stems from its ability to modify energy metabolism in cells and animal models.
In rodent studies, SR9009 has been reported to increase mitochondrial content in skeletal muscle and improve exercise endurance under some conditions. These findings led to popular descriptions such as an exercise mimetic, although that term oversimplifies the biology. Effects vary by dose, timing, tissue, and model. The compound's influence on circadian pathways means that time of administration can matter in experiments. Whether similar metabolic changes occur in humans remains largely unexplored in controlled published trials.
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.
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.
==== Charge site-initiated cleavage ==== The driving force of charge site-initiated fragmentation is the inductive effect of the charge site in radical cations. The electrons from the bond adjacent to the charge-bearing atom migrate to that atom, neutralizing the original charge and causing it to move to a different site. This term is also called inductive cleavage and is an example of heterolytic bond cleavage.
=== Pharmacokinetics === The metabolism and metabolites of SDA have been studied. It showed more rapid clearance than MDA in rodents and hence may have a shorter elimination half-life and/or duration.
=== Individual reactions === The removal of the blue checkmark and Twitter Blue have sparked controversy. Actress Alyssa Milano added to her Twitter profile that she would not be paying for Twitter Blue. The Twitter account for Elmo tweeted that, "Elmo will miss you, little blue check mark". The blue checkmark has also caused crosscurrents between Twitter users, with technology journalist Joanna Stern writing that she "likes editing tweets", and appears to have distanced herself from the blue checkmark. Morning Consult journalist Bobby Blanchard asked Twitter to remove his blue checkmark. Other personalities and entities appeared confused as to why their blue checkmarks appeared despite not subscribing to Twitter Blue, such as journalist Maggie Haberman, actors Ben Schwartz and Elijah Wood, astrophysicist Neil deGrasse Tyson, and the Massachusetts Institute of Technology. The Twitter account for the Auschwitz-Birkenau State Museum clarified that it had not paid for Twitter Blue either. Model Chrissy Teigen compared her blue checkmark to the film It Follows (2014) and was able to get hers removed by changing her username, telling speechwriter Jon Favreau. Favreau later stated that he believed Musk was "capricious" in his actions and did not want to be potentially suspended for unverifying his account. Likewise, stand-up comedian and actor Patton Oswalt changed his username to remove his blue checkmark. dril, part of Twitter's secretive list of users to promote and of "Weird Twitter", removed his blue checkmark by changing his display name to "slave to Woke".
==== Manifestations of systemic conditions ==== Occasionally systemic conditions may be the sole cause of gingival inflammation rather than merely influencing background plaque-induced gingivitis. Certain mucocutaneous produce gingival inflammation which may manifest as desquamative gingivitis or oral ulceration. Such conditions include lichen planus, pemphigoid, pemphigus vulgaris, erythema multiforme, and lupus erythematosus. Allergic reactions may also trigger gingival lesions. Sources of allergens include toothpastes, mouthwash, chewing gum, foods, additives, medicines, dental restorative materials, mercury, nickel and acrylic, acrylic. Plasma cell gingivitis is a rare condition thought to be a hypersensitivity reaction. Lichenoid lesions may also occur on the gingival mucosa.
Therefore, hyperhomocysteinemia is a possible risk factor for coronary artery disease. Coronary artery disease occurs when an atherosclerotic plaque blocks blood flow to the coronary arteries, which supply the heart with oxygenated blood. Hyperhomocysteinemia has also been correlated with the occurrence of blood clots, heart attacks, and strokes, although it is unclear whether hyperhomocysteinemia is an independent risk factor for these conditions. Hyperhomocysteinemia has also been associated with early-term spontaneous abortions and with neural tube defects.
Sources: en.wikipedia.org
Whereas in the course of human affairs history has shown that it may become necessary for a people to resolve the political affiliations which have connected them with another people and to assume amongst other nations the separate and equal status to which they are entitled: And Whereas in such event a respect for the opinions of mankind requires them to declare to other nations the causes which impel them to assume full responsibility for their own affairs: Now Therefore, We, The Government of Rhodesia, Do Hereby Declare: That it is an indisputable and accepted historic fact that since 1923 the Government of Rhodesia have exercised the powers of self-government and have been responsible for the progress, development and welfare of their people; That the people of Rhodesia having demonstrated their loyalty to the Crown and to their kith and kin in the United Kingdom and elsewhere through two world wars, and having been prepared to shed their blood and give of their substance in what they believed to be the mutual interests of freedom-loving people, now see all that they have cherished about to be shattered on the rocks of expediency; That the people of Rhodesia have witnessed a process which is destructive of those very precepts upon which civilization in a primitive country has been built, they have seen the principles of Western democracy, responsible government and moral standards crumble elsewhere, nevertheless they have remained steadfast; That the people of Rhodesia fully support the requests of their government for sovereign independence but have witnessed the consistent refusal of the Government of the United Kingdom to accede to their entreaties; That the Government of the United Kingdom have thus demonstrated that they are not prepared to grant sovereign independence to Rhodesia on terms acceptable to the people of Rhodesia, thereby persisting in maintaining an unwarrantable jurisdiction over Rhodesia, obstructing laws and treaties with other states and the conduct of affairs with other nations and refusing assent to laws necessary for the public good, all this to the detriment of the future peace, prosperity and good government of Rhodesia; That the Government of Rhodesia have for a long period patiently and in good faith negotiated with the Government of the United Kingdom for the removal of the remaining limitations placed upon them and for the grant of sovereign independence; That in the belief that procrastination and delay strike at and injure the very life of the nation, the Government of Rhodesia consider it essential that Rhodesia should attain, without delay, sovereign independence, the justice of which is beyond question; Now Therefore, We The Government of Rhodesia, in humble submission to Almighty God who controls the destinies of nations, conscious that the people of Rhodesia have always shown unswerving loyalty and devotion to Her Majesty the Queen and earnestly praying that we and the people of Rhodesia will not be hindered in our determination to continue exercising our undoubted right to demonstrate the same loyalty and devotion, and seeking to promote the common good so that the dignity and freedom of all men may be assured, Do, By This Proclamation, adopt, enact and give to the people of Rhodesia the Constitution annexed hereto;
=== Infections === The second most common cause of SJS and TEN is infection, particularly in children. This includes upper respiratory infections, otitis media, pharyngitis, and Epstein–Barr virus, Mycoplasma pneumoniae and cytomegalovirus infections. The routine use of medicines such as antibiotics, antipyretics and analgesics to manage infections can make it difficult to identify if cases were caused by the infection or medicines taken. Viral diseases reported to cause SJS include: herpes simplex virus (possibly; is debated), AIDS, coxsackievirus, influenza, hepatitis, and mumps. In pediatric cases, Epstein–Barr virus and enteroviruses have been associated with SJS. Recent upper respiratory tract infections have been reported by more than half of patients with SJS. Bacterial infections linked to SJS include group A beta-hemolytic streptococci, diphtheria, brucellosis, lymphogranuloma venereum, mycobacteria, Mycoplasma pneumoniae, rickettsial infections, tularemia, and typhoid. Fungal infections with coccidioidomycosis, dermatophytosis and histoplasmosis are also considered possible causes. Malaria and trichomoniasis, protozoal infections, have also been reported as causes.
Protein kinases act on proteins, by phosphorylating them on their serine, threonine, tyrosine, or histidine residues. Phosphorylation can modify the function of a protein in many ways. It can increase or decrease a protein's activity, stabilize it or mark it for destruction, localize it within a specific cellular compartment, and it can initiate or disrupt its interaction with other proteins. The protein kinases make up the majority of all kinases and are widely studied. These kinases, in conjunction with phosphatases, play a major role in protein and enzyme regulation as well as signalling in the cell. A common point of confusion arises when thinking about the different ways a cell achieves biological regulation. There are countless examples of covalent modifications that cellular proteins can undergo; however, phosphorylation is one of the few reversible covalent modifications. This provided the rationale that phosphorylation of proteins is regulatory. The potential to regulate protein function is enormous given that there are many ways to covalently modify a protein in addition to regulation provided by allosteric control. In his Hopkins Memorial Lecture, Edwin Krebs asserted that allosteric control evolved to respond to signals arising from inside the cell, whereas phosphorylation evolved to respond to signals outside of the cell. This idea is consistent with the fact that phosphorylation of proteins occurs much more frequently in eukaryotic cells in comparison to prokaryotic cells because the more complex cell type evolved to respond to a wider array of signals.
Astatine is known to react with its lighter homologs iodine, bromine, and chlorine in the vapor state; these reactions produce diatomic interhalogen compounds with formulas AtI, AtBr, and AtCl. The first two compounds may also be produced in water—astatine reacts with iodine/iodide solution to form AtI, whereas AtBr requires (aside from astatine) an iodine/iodine monobromide/bromide solution. The excess of iodides or bromides may lead to AtBr2− and AtI2− ions, or in a chloride solution, they may produce species like AtCl2− or AtBrCl− via equilibrium reactions with the chlorides. Oxidation of the element with dichromate (in nitric acid solution) showed that adding chloride turned the astatine into a molecule likely to be either AtCl or AtOCl. Similarly, AtOCl2− or AtCl2− may be produced. The polyhalides PdAtI2, CsAtI2, TlAtI2, and PbAtI are known or presumed to have been precipitated. In a plasma ion source mass spectrometer, the ions [AtI]+, [AtBr]+, and [AtCl]+ have been formed by introducing lighter halogen vapors into a helium-filled cell containing astatine, supporting the existence of stable neutral molecules in the plasma ion state. No astatine fluorides have been discovered yet. Their absence has been speculatively attributed to the extreme reactivity of such compounds, including the reaction of an initially formed fluoride with the walls of the glass container to form a non-volatile product.
The five other countries, including the second and third largest beef producers, France and the United Kingdom, respectively, permitted their use. This had resulted in disputes, with countries that had no prohibitions arguing that the restrictions by the others acted as non-tariff trade barriers. In response to the public outcry, in combination with the discovery that DES was a teratogen, in 1980 the EU began to issue regulations, beginning with prohibiting the use of stilbenes and thyrostatics by the European Community Council of Agriculture Ministers in 1980, and commissioning of a scientific study into the use of estradiol, testosterone, progesterone, trenbolone, and zeranol in 1981. The European Consumers' Organisation (BEUC) lobbied for a total ban upon growth hormones, opposed, with partial success, by the pharmaceutical industry. (In 1987 the European Federation of Animal Health (FEDESA), formed to represent, amongst other things, companies that manufactured growth hormones.) Neither European farmers nor the meat processing industry took a stance on the matter. With the help of the BEUC consumer boycotts of veal products, sparked by the Italian scandals and similar reports in France and Germany, spread across the EU, causing companies such as Hipp and Alete to withdraw their veal products, while veal prices dropped in France, Belgium, West Germany, Ireland, and the Netherlands. Because of the fixed purchases guaranteed by the EU's Common Agricultural Policy, ECU 10 million came out of the EU budget.
Sources: en.wikipedia.org
=== VfB Leipzig (1893–1946) === The club was formed as VfB Leipzig on 13 May 1896, out of the football department of the gymnastics club Allgemeine Turnverein 1845 Leipzig. However, the club laid claim to an earlier date of origin by referring back to a club that was merged with VfB Leipzig in 1898, the SC Sportbrüder Leipzig, which was one of four football clubs formed in Leipzig in 1893. Following the merger with SC Sportbrüder Leipzig, the club competed under the name VfB Sportbrüder 1893 Leipzig. VfB Sportbrüder 1893 Leipzig was one of the original 86 teams that came together in the city on 28 January 1900 to form the German Football Association (DFB). On 2 May 1900, the Sportbrüder 1893 part of the name was dropped, and the team became again known as VfB Leipzig.
== Discovery == German chemist Felix Ehrlich discovered isoleucine while studying the composition of beet-sugar molasses 1903. In 1907 Ehrlich carried out further studies on fibrin, egg albumin, gluten, and beef muscle in 1907. These studies verified the natural composition of isoleucine. Ehrlich published his own synthesis of isoleucine in 1908.
During the bidding process, 41 cities with 42 existing, fully functional venues with regular tenants (except Olympic Stadium in Montreal) and two venues then under construction (Allegiant Stadium in Las Vegas and SoFi Stadium in Los Angeles) submitted to be part of the bid: three venues in three cities in Mexico, six venues in six cities in Canada, and 35 venues in 32 cities in the United States. A first-round elimination removed nine venues and nine cities. A second-round elimination cut an additional nine venues in six cities, while three venues in three cities (Soldier Field in Chicago, U.S. Bank Stadium in Minneapolis, and BC Place in Vancouver) dropped out because FIFA was unwilling to negotiate financial details. After Montreal dropped out in July 2021 because it lacked provincial funding and support to renovate Olympic Stadium, Vancouver rejoined the bid as a candidate city in April 2022, bringing the total number to 24 venues, each in its own city or metropolitan area. On June 16, 2022, the sixteen host cities–two in Canada, three in Mexico, and eleven in the United States–were announced by FIFA: Atlanta, Boston, Dallas, Guadalajara, Houston, Kansas City, Los Angeles, Mexico City, Miami, Monterrey, New York/New Jersey, Philadelphia, San Francisco Bay Area, Seattle, Toronto, and Vancouver. Eight of the sixteen chosen stadiums had permanent artificial turf surfaces that were replaced with grass under the direction of FIFA and a University of Tennessee–Michigan State University research team.
=== Stoichiometry and metabolic cost in cell === The table below lists the abundance of amino acids in E.coli cells and the metabolic cost (ATP) for synthesis of the amino acids. Negative numbers indicate the metabolic processes are energy favorable and do not cost net ATP of the cell. The abundance of amino acids includes amino acids in free form and in polymerization form (proteins).
About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium. All 11 are necessary for life. The remaining elements are trace elements, of which more than a dozen are thought on the basis of good evidence to be necessary for life. All of the mass of the trace elements put together (less than 10 grams for a human body) do not add up to the body mass of magnesium, the least common of the 11 non-trace elements.
Sources: en.wikipedia.org
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.
Research-grade purity indicates a supplier's measured percentage of the intended compound. It does not guarantee safety, sterility, or suitability for human consumption. Buyers should request a certificate of analysis with chromatograms and test methods.
Sports regulators prohibit SR9009 because it is a non-approved substance with potential performance-altering effects. Its presence can be detected in anti-doping testing. Athletes are responsible for substances found in their samples.
It is a synthetic compound studied as an agonist of REV-ERB nuclear receptors. It is not an approved medicine and has mainly been examined in laboratory and animal research.