The short version of circadian rhythm fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
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.
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 |
|---|---|---|
| Common synonyms | SR9009; Stenabolic | Nickname is not a chemical name. |
| Typical analytical method | LC-MS/MS | Often with isotope-labeled internal standard. |
| Storage temperature | -20 °C | Desiccated and protected from light. |
| Solution stability | DMSO stock; avoid freeze-thaw | Store at -20 to -80 °C. |
| Regulatory status | Not approved; varies by country | May be restricted as research chemical. |
SR9009 is often grouped with compounds studied for circadian and metabolic regulation rather than with classical anabolic steroids. Its interactions with nuclear receptors differ from those of androgen receptor ligands, and its proposed mechanisms involve transcriptional control rather than direct hormone signaling. Some sources classify it as a metabolic modulator because of observed effects on energy utilization. The distinction matters for regulation and for interpreting research results across different compound classes.
SR9009 is a synthetic small molecule developed as a REV-ERB agonist. It binds to REV-ERBα and REV-ERBβ, nuclear receptors that help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, the compound alters lipid and glucose handling and influences skeletal muscle oxidative capacity. Its exact effects in humans remain largely uncharacterized because controlled clinical trials have not been reported. The molecule is frequently described in preclinical literature as a metabolic modulator.
Regulatory agencies have not approved SR9009 for human therapeutic use. It is typically sold as a research chemical with labels stating that it is not for human consumption. The World Anti-Doping Agency prohibits the substance in sport, generally under the category of non-approved substances. Customs and national laws may restrict importation, sale, or possession. Product quality and legal status can vary by country and vendor, and therapeutic claims are not permitted in regulated advertising because the compound lacks approval.
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.
Nike, Inc announces it will sell "limited quantities" of a replica goalkeeper shirt worn by England goalkeeper Mary Earps during the 2023 Women's World Cup after around 150,000 people signed an online petition calling for them to be made available. A police officer is taken to hospital with critical injuries after being hit by a train while trying to help a distressed man on the railway track in Nottinghamshire. 25 August – Hartwig Fischer announces he will step down as director of the British Museum after treasures were stolen from the London institution. 26 August – Two people are killed after driving a car into a flooded road in the Mossley Hill area of Liverpool. 27 August – The Metropolitan Police launch an investigation into a possible data breach involving details about thousands of their officers after "unauthorised access" was gained to the system of one of its suppliers. 29 August – Nottinghamshire Police officer Sgt Graham Saville, 46, who was struck by a train while trying to help a distressed man on the railway track, dies in hospital from injuries sustained in the incident. London's Ultra Low Emission Zone is expanded to include the whole of Greater London. 30 August – England's Autumn 2023 flu vaccination and COVID-19 booster programme is brought forward by a month, from October to September, as scientists from the UK Health Security Agency monitor the BA.2.86 variant. Although it is not a variant of concern, it is being monitored due to its high number of mutations.
==== Chiral stationary phase (CSP) ==== In the direct enantiomer separation the most popular approach is use of chiral stationary phases. In this case the site of the chiral selector is on the stationary phase. Stationary phase consist of an inert solid support (usually silica microparticles) on to the surface of which a single enantiomer of a chiral molecule (selector) is either coated/adsorbed or chemically linked and that forms the chiral stationary phase. Commonly used chiral selectors include polysaccharides, proteins, cyclodextrins, etc. An interesting review of chiral stationary phase development and application in chiral analysis appeared in LCGC magazine, 2011.
As a precaution, patients undergoing permanent brachytherapy are advised not to hold small children immediately after treatment and not to be in the vicinity of pregnant women, since low-dose radioactive sources (seeds) remain in the body after treatment with permanent brachytherapy. This is to protect the particularly radiation-sensitive tissues of a fetus or infant.
== Associated conditions == Diseases of the pituitary, the gland that produces, among others, the hormone ACTH Hypopituitarism, the hyposecretion of ACTH in the pituitary, leading to secondary adrenal insufficiency (a form of hypocorticism) Addison's disease, the primary adrenal insufficiency (another form of hypocorticism) Cushing's syndrome, hypercorticism, one of the causes is hypersecretion of ACTH Small cell carcinoma, a common cause of ACTH secreted ectopically Congenital adrenal hyperplasia, diseases in the production of cortisol Nelson's syndrome, the rapid enlargement of the ACTH producing pituitary after the removal of both adrenal glands Adrenoleukodystrophy, can be accompanied by adrenal insufficiency West syndrome ("infantile spasms"), a disease where ACTH is used as a therapy Postorgasmic illness syndrome (POIS), through production of tyrosine hydroxylase and dopamine β-hydroxylase, which two enzymes comprise the biochemical mechanism by which norepinephrine and epinephrine are produced. Critical illness-related corticosteroid insufficiency DAVID syndrome, a genetic disorder that is characterized by adrenocorticotropic hormone deficiency combined with common variable immunodeficiency and hypogammaglobulinemia.
Sources: en.wikipedia.org
Potentiation of GABAA receptor activity (by kavain, dihydrokavain, methysticin, dihydromethysticin, and yangonin). Inhibition of the reuptake of norepinephrine (by kavain and methysticin) and possibly also of dopamine (by kavain and desmethoxyyangonin). Binding to the CB1 receptor (by yangonin). Inhibition of voltage-gated sodium channels and voltage-gated calcium channels (by kavain and methysticin). Monoamine oxidase B reversible inhibition (by all six of the major kavalactones). Methanolic leaf extracts of Hawaiian kava cultivars showed stronger binding inhibition to several CNS receptors—including GABAA, dopamine D2, opioid (μ, δ), and histamine (H1, H2)—than root extracts, suggesting that compounds beyond the main kavalactones may contribute to the pharmacological effects of kava leaves.
21 October – Stephen Flynn, the SNP's leader at Westminster, tables a motion urging the UK government to formally strip Prince Andrew of his royal titles following allegations made against him in the memoirs of Virginia Giuffre. A third, unnamed member of the grooming gang inquiry panel, resigns. Reform UK elects a new leader and deputy leader on Cornwall Council. 22 October – Angela Rayner gives her formal resignation speech to the House of Commons after leaving the frontbench. Jim Gamble becomes the second chair of the grooming gang inquiry to resign, while a fourth member resigns from the inquiry's panel as Starmer tells Prime Minister's Questions that the inquiry will look at racial and religious motives. King Charles and Queen Camilla arrive in Rome ahead of a historic state visit to Vatican City, where they will meet Pope Leo XIV. Reform UK's Linden Kemkaran issues a statement calling for councillors to back her in writing following advice to do so from her party's headquarters. 3 Labour members of Swindon Borough Council defect to the Green Party of England and Wales. 23 October – Lindsay Whittle wins the 2025 Caerphilly by-election for Plaid Cymru, taking the seat from Labour, who had held it since the Senedd was established in 1999. The UK government says it will not give MPs parliamentary time to debate whether Prince Andrew should be stripped of his titles. 24 October – 3 Scottish Green councillors defect to Jeremy Corbyn's Your Party, giving the party its first Scottish representatives.
In the eastern United States in the early 2000s, sulfate particles were estimated to account for 25% or more of all air pollution. Exposure to sulfur dioxide emissions by coal power plants (coal PM2.5) in the US was associated with 2.1 times greater mortality risk than exposure to PM2.5 from all sources. Meanwhile, the Southern Hemisphere had much lower concentrations due to being much less densely populated, with an estimated 90% of the human population in the north. In the early 1990s, anthropogenic sulfur dominated in the Northern Hemisphere, where only 16% of annual sulfur emissions were natural, yet amounted for less than half of the emissions in the Southern Hemisphere.
KFC is a subsidiary of Yum! Brands, one of the largest restaurant companies in the world. KFC had sales of $23 billion in 2013. KFC is incorporated under Delaware General Corporation Law, and has its headquarters at 1441 Gardiner Lane, Louisville, Kentucky, in a three-story colonial style building known colloquially as the "White House" due to its resemblance to the US president's home. The headquarters contain executive offices and the company's research and development facilities. In 2025, Yum! Brands plans to move the KFC headquarters to Plano, Texas.
Allergic diseases are strongly familial; identical twins are likely to have the same allergic diseases about 70% of the time; the same allergy occurs about 40% of the time in non-identical twins. Allergic parents are more likely to have allergic children and those children's allergies are likely to be more severe than those in children of non-allergic parents. Some allergies, however, are not consistent along genealogies; parents who are allergic to peanuts may have children who are allergic to ragweed. The likelihood of developing allergies is inherited and related to an irregularity in the immune system, but the specific allergen is not. The risk of allergic sensitization and the development of allergies varies with age, with young children most at risk. Several studies have shown that IgE levels are highest in childhood and fall rapidly between the ages of 10 and 30 years. The peak prevalence of hay fever is highest in children and young adults, and the incidence of asthma is highest in children under 10. Ethnicity may play a role in some allergies; however, racial factors have been difficult to separate from environmental influences and changes due to migration. It has been suggested that different genetic loci are responsible for asthma, to be specific, in people of European, Hispanic, Asian, and African origins.
Sources: en.wikipedia.org
Most of the isotopes of each chemical element present in the Earth today were formed by such processes no later than the time of our planet's condensation from the solar protoplanetary disc, around 4.5 billion years ago. The exceptions to these so-called primordial elements are those that have resulted from the radioactive disintegration of unstable parent nuclei as they progress down one of several decay chains, each of which terminates with the production of one of the 251 stable isotopes known to exist. Aside from cosmic or stellar nucleosynthesis, and decay chains the only other ways of producing a chemical element rely on atomic weapons, nuclear reactors (natural or manmade) or the laborious atom-by-atom assembly of nuclei with particle accelerators. Unstable isotopes decay to their daughter products (which may sometimes be even more unstable) at a given rate; eventually, often after a series of decays, a stable isotope is reached: there are 251 stable isotopes in the universe. In stable isotopes, light elements typically have a lower ratio of neutrons to protons in their nucleus than heavier elements. Light elements such as helium-4 have close to a 1:1 neutron:proton ratio. The heaviest elements such as uranium have close to 1.5 neutrons per proton (e.g. 1.587 in uranium-238). No nuclide heavier than lead-208 is stable; these heavier elements have to shed mass to achieve stability, mostly by alpha decay.
is the consumption rate of A, a reactant. This is equal to the rate expression A is involved in. The rate expression is often related to the fractional conversion both through the consumption of A and through any k changes through temperature changes that are dependent on conversion.
John Gross FRSL (12 March 1935 – 10 January 2011); editor of The Times Literary Supplement, senior book editor and book critic on The New York Times, theatre critic for The Sunday Telegraph; assistant editor on Encounter; literary editor of The New Statesman and Spectator; author of The Rise and Fall of the Man of Letters, James Joyce, Shylock: Four Hundred Years in the Life of a Legend; works as editor and anthologist include After Shakespeare: Writing inspired by the world's greatest author, The Oxford Book of Aphorisms, The Oxford Book of Essays, The Oxford Book of Comic Verse, The New Oxford Book of English Prose, The New Oxford Book of Literary Anecdotes, The Modern Movement, Dickens and the Twentieth Century, and The Oxford Book of Parodies; was trustee of London's National Portrait Gallery; served on the English Heritage advisory committee on blue plaques; advised British government on the award of public honours He served as chairman of the judges of the Booker Prize,; member of The Literary Society; director of Times Newspaper holdings, the publishers of The Times and The Sunday Times; married to Miriam Gross, literary editor; had two children, Tom Gross and Susanna Gross.
The Joint Committee for Traceability in Laboratory Medicine or JCTLM is collaboration between the International Bureau of Weights and Measures (BIPM), the International Federation for Clinical Chemistry and Laboratory Medicine (IFCC), and the International Laboratory Accreditation Cooperation (ILAC). The goal of the JCTLM is to provide a worldwide platform to promote and give guidance on internationally recognized and accepted equivalence of measurements in laboratory medicine and traceability to appropriate measurement standards.
Sources: en.wikipedia.org
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.
Solid material is usually kept at -20 °C, desiccated, and protected from light. Dimethyl sulfoxide stocks should be stored cold and subjected to minimal freeze-thaw cycles. Aqueous solutions are generally less stable and should be prepared fresh when possible.
Legality depends on the country and the intended use. It is not an approved medicine, and some places restrict or ban sales for human consumption. Buyers should verify local rules and product documentation before procurement.
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.