circadian rhythm 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.
Updated 2026-04-15. Numbers and descriptions here follow the published literature rather than marketing material.
Several misconceptions surround SR9009. It is often described as a SARM, a steroid, or an exercise pill, but its known target is the REV-ERB receptor family. Rodent studies have examined exercise capacity and metabolic markers, yet human outcomes remain unproven. Oral bioavailability appears low in animals, and human pharmacokinetics are not well characterized. Online products may contain impurities or different compounds, so identity and purity testing are important for research use.
Analytical chemists detect SR9009 with liquid chromatography-tandem mass spectrometry, commonly abbreviated LC-MS/MS. Sample preparation may involve protein precipitation, liquid-liquid extraction, or solid-phase extraction before analysis. Laboratories can target the parent compound or its metabolites, depending on the matrix and the purpose of testing. Anti-doping methods require sensitive and specific assays because concentrations in biological samples can be low. Reference standards and validated methods are essential for reliable identification and quantification.
Stability depends on physical form, temperature, light exposure, and solvent. Solid SR9009 is generally stored cold and dry, with protection from light to limit degradation. Dimethyl sulfoxide stocks are common for laboratory work, but repeated freeze-thaw cycles can reduce compound integrity. Aqueous solutions may be less stable than organic stocks, and the ethyl ester in the structure can be susceptible to hydrolysis under certain conditions. Researchers typically validate storage conditions and recheck purity before quantitative experiments, especially when using archived material.
Regulatory treatment of SR9009 varies by country and region. It is not approved as a pharmaceutical, and several jurisdictions restrict its sale for human consumption. Some authorities classify it as a research chemical, a prescription-only substance, or a prohibited performance-enhancing agent in sport. Purchasers may encounter certificates of analysis, but these documents do not guarantee identity, purity, or legality. In research settings, institutional safety reviews and controlled procurement help ensure that materials are handled under appropriate oversight. The absence of harmonized rules means that legal status can change and requires verification.
Analytical identification of SR9009 typically relies on liquid chromatography coupled with tandem mass spectrometry. In biological samples, researchers first separate the compound from matrix components using protein precipitation, liquid-liquid extraction, or solid-phase extraction. High-performance liquid chromatography with ultraviolet detection and nuclear magnetic resonance spectroscopy can support structural confirmation of reference materials. Because SR9009 is a small, relatively lipophilic molecule, reverse-phase columns and acidic mobile phases are common. Laboratories often include isotope-labeled internal standards to improve quantification and to correct for ion suppression.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Not approved for human use | Research-use-only status in many markets |
| WADA status | Prohibited in sport | Generally listed as a non-approved substance |
| Detection technique | LC-MS/MS | Common for urine and blood analysis |
| Common alias | Stenabolic | Informal market nickname, not a pharmacopoeial name |
| Purity check | HPLC or LC-UV | Independent certificate of analysis is typical |
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.
SR9009 is frequently discussed in fitness and research-chemical contexts, yet it has no approved medical indication. Regulatory agencies have not authorized it for human use, and it is not a standard prescription drug. Some sports organizations list it as a prohibited substance because of its potential performance-enhancing properties. Published human data are sparse, so claims about its effects in people often rely on animal models or anecdotal reports. Quality and identity of online materials can vary widely.
SR9009 is a synthetic small molecule studied as a REV-ERB agonist. REV-ERBα and REV-ERBβ are nuclear receptors that help regulate circadian rhythms and metabolic gene expression. The compound was identified in academic screening efforts to find synthetic ligands for these receptors. In cell and animal studies, SR9009 alters transcription of genes involved in lipid and glucose metabolism, and it can shift circadian behavior. It is not an approved therapeutic agent.
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.
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.
=== 23 January === The El-Jeili oil refinery caught fire with smoke being seen from Omdurman and Khartoum Bahri. The SAF claimed that the RSF had set fire to the facility, while the RSF claimed that it caught fire due to incendiary barrel bombs dropped by the Sudanese Air Force. Two people were killed by RSF shelling on the Abu Shouk IDP camp. An indefinite strike was launched by employees of the Bashair Hospital in Khartoum after an RSF member opened fire inside the facility the previous day.
=== Alternative treatments for wounds: leeches and maggots === Medical leeches were cleared as a medical device in 2004 after being an indispensable tool in the 19th century and even in use in the Middle Ages. This unique use of creatures is utilized in many surgeries today. Leeches have the ability to assist with compromised tissue with the components of their saliva. Their saliva contains a local anesthetic, thrombin inhibitor, antibiotic properties and a histamine-like vasodilator. These capabilities help in surgeries such as transplants, skin grafts, and even reconstructive surgeries. The leeches help localize the wound and help produce blood flow. This is helpful in operations where blood clots occur and they help dilate the blood vessels. Baron Dominique Jean Larrey, surgeon-in-chief of Napoleon's Grande Armée pioneered the use of maggots to prevent infection in wounds. They were also used by military medical aids during World War II. They worked as biomedical debriding agents by ingesting bacteria and breaking them down within their intestines. Maggots give off an enzyme that disinfects wounds and promotes healing and this is why they became the first organism in the United States that were used as a medical device in January 2004.
==== Adverse effects ==== The most commonly reported adverse effects of nabiximol is dizziness, followed by drownsiness, fatigue, and nausea. Other adverse effects include anorexia, constipation, diarrhea, dysgeusia (taste disorder), oral ulcer, staining of tooth, upper abdominal pain, vomiting, xerostomia (dry mouth), confusion, and disorientation.
Cox Plate (2009, 2010), Tattersalls Gold Cup (2011, 2012), Prince of Wales's Stakes (2012) (foaled 2006). (death announced on this date) 23 October – Piera McArthur, painter (born 1929). 27 October – Robert Neale, literary scholar and university orator (Massey University) (born 1933). 29 October – Mick Bremner, rugby union player (Auckland, Canterbury, national team) (born 1930). 30 October – Alan Vest, association football player (Perth Azzurri, national team) and manager (Sarawak FA, Perth Glory) (born 1939). 31 October Chris Barfoot, realtor (Barfoot & Thompson), conservationist (Tahuna Torea Nature Reserve), and pacifist, secretary of Anglican Pacifist Fellowship New Zealand (1962–1968, 1992–2016) (born 1930). Tim Finn, viticulturist (Neudorf Vineyards) (born 1946).
Sources: en.wikipedia.org
31 October The Independent Schools Council, which represents around 1,400 private schools in the UK, votes to take legal action against government plans to end their tax exemption status from January 2025. GB News is fined £100,000 by Ofcom for breaking impartiality rules with a programme featuring the former Prime Minister Rishi Sunak.
== Evolution == Some 23-million-year-old fossils of arapaima or a very similar species have been found in the Miocene Villavieja Formation of Colombia. Museum specimens are found in France, England, the United States, Brazil, Guyana, Ecuador and Perú. This makes them some of the oldest known species of freshwater fish.
Watson, Crick, Wilkins and Franklin all worked in MRC laboratories. Crick and Watson felt that they had benefited from collaborating with Wilkins. They offered him a co-authorship on the article that first described the double helix structure of DNA. Wilkins turned down the offer, a fact that may have led to the terse character of the acknowledgement of experimental work done at King's College in the eventual published paper. Rather than make any of the DNA researchers at King's College co-authors on the Watson and Crick double helix article, the solution that was arrived at was to publish two additional papers from King's College along with the helix paper. Brenda Maddox suggests that because of the importance of her experimental results in Watson and Crick's model building and theoretical analysis, Franklin should have had her name on the original Watson and Crick paper in Nature. Franklin and Gosling submitted their own joint "second" paper to Nature at the same time as Wilkins, Stokes, and Wilson submitted theirs (i.e. the "third" paper on DNA). Watson's portrayal of Franklin in The Double Helix was negative and gave the appearance that she was Wilkins' assistant and was unable to interpret her own DNA data. However, according to Nathaniel C. Comfort, a historian of medicine at Johns Hopkins University, Franklin's colleague Aaron Klug believed that Franklin "..was 'two steps away' from the double helix. After completing an analysis of her lab notebook, Klug stated that she surely would have had it.
=== Pharmacokinetics === The time that it takes for serum concentrations of clinafloxacin to reach the maximum concentration (Cmax) in healthy volunteers after taking a dose by mouth is 0.7 hours. The elimination half-life in humans is 6.1 hours. Steady state levels of clinafloxacin are achieved in 3 days of twice daily dosing by mouth in healthy volunteers. About half of an administered clinafloxacin dose is found unchanged in the urine, meaning that the drug is cleared from the blood stream roughly equally by hepatic metabolism (liver-induced degradation) and renal elimination (kidney-mediated removal).
The European Aviation Safety Agency (EASA) is tasked by Article 15(4) of Regulation (EC) No 216/2008 of the European Parliament and of the Council of February 20, 2008, to provide an annual review of aviation safety. The Annual Safety Review presents statistics on European and worldwide civil aviation safety. Statistics are grouped according to type of operation, for instance, commercial air transport, and aircraft category, such as aeroplanes, helicopters, gliders, etc. The Agency has access to accident and statistical information collected by the International Civil Aviation Organization (ICAO). States are required, according to ICAO Annex 13, on Aircraft Accident and Incident Investigation, to report to ICAO information, on accidents and serious incidents to aircraft with a maximum certificated take-off mass (MTOM) over 2250 kg. Therefore, most statistics in this review concern aircraft above this mass. In addition to the ICAO data, a request was made to the EASA Member States to obtain light aircraft accident data. Furthermore, data on the operation of aircraft for commercial air transport were obtained from both ICAO and the NLR Air Transport Safety Institute.
Sources: en.wikipedia.org
Legality depends on the country and the intended use. In many places it is not approved as a medicine and may be sold only as a research chemical. Importation or possession can be restricted, and sports organizations prohibit it.
Anti-doping laboratories typically use LC-MS/MS to detect SR9009 or its metabolites in urine or blood. The exact assay depends on the laboratory and the testing program. Detection can be challenging because the compound may be rapidly metabolized and present at low levels.
Stenabolic is an informal nickname used in online fitness and research-chemical markets, not an official drug name. It likely references reported effects on endurance in rodent studies. The nickname does not imply approval or proven human benefit.
The most common approach is liquid chromatography-tandem mass spectrometry, often after extraction from blood, urine, or tissue. Ultraviolet detection and nuclear magnetic resonance spectroscopy are used mainly for reference material characterization. Isotope-labeled internal standards improve accuracy.