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.
Updated 2026-02-17. Numbers and descriptions here follow the published literature rather than marketing material.
Storage recommendations for SR9009 reference material typically specify a freezer at -20 °C or lower, with protection from moisture and light. Repeated freeze-thaw cycles can degrade small molecules and introduce variability. Stock solutions in dimethyl sulfoxide are often aliquoted to avoid repeated handling. Stability studies may examine degradation under heat, humidity, and light exposure. The compound's thiophene and nitro groups can participate in reactions that alter analytical signals over time, so such changes affect quantitative results.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | -20 °C or lower | Desiccated and protected from light |
| Common analytical method | LC-MS/MS | Detects parent drug and metabolites |
| Solubility class | Lipophilic; soluble in organic solvents | Low aqueous solubility |
| Molecular weight | 437.94 g/mol | Calculated from reported formula |
| Synonyms | SR9009; REV-ERB agonist | Code name used in scientific literature |
SR9009 binds REV-ERB receptors and alters their repressive activity on target genes. This action can change transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. In rodent studies, treated animals have shown changes in muscle oxidative capacity and exercise performance, though effects vary by dose, duration, and model. The precise molecular steps connecting receptor binding to whole-body outcomes are still an active area of investigation. Findings in animals do not automatically translate to humans.
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.
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.
The mechanism of action involves binding to REV-ERB receptors and recruiting corepressor complexes, which represses target gene transcription. This contrasts with many nuclear receptor agonists that activate transcription. Downstream effects may include changes in autophagy, mitochondrial biogenesis, and lipid handling, but the precise pathways remain an active area of study. Whether these molecular events translate into meaningful physiological effects in humans is unresolved. Most evidence comes from cultured cells and rodent models rather than human participants.
SR9009 is a synthetic small molecule developed as an agonist of the nuclear receptors REV-ERBα (NR1D1) and REV-ERBβ (NR1D2). These receptors help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, SR9009 alters transcription of genes involved in lipid metabolism, inflammation, and mitochondrial function. It is not an approved medicine, and its pharmacological profile in humans remains largely uncharacterized. The compound is frequently discussed in the context of circadian biology and metabolic research rather than clinical use.
=== Generic names === Anastrozole is the generic name of the drug and its INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name, BANTooltip British Approved Name, and JANTooltip Japanese Accepted Name.
In addition to his third share of the 1962 Nobel Prize for Physiology or Medicine, he received many awards and honours, including the Royal and Copley medals of the Royal Society (1972 and 1975), and also the Order of Merit (on 27 November 1991); he refused an offer of a CBE in 1963, but was often referred to in error as 'Sir Francis Crick' and even on occasions as 'Lord Crick'. He was elected an EMBO Member in 1964. The award of Nobel Prizes to John Kendrew and Max Perutz, and to Crick, Watson, and Wilkins was satirised in a short sketch in the BBC TV programme That Was The Week That Was with the Nobel Prizes being referred to as 'The Alfred Nobel Peace Pools'. He was an elected member of the American Academy of Arts and Sciences (1962), the United States National Academy of Sciences (1969), and the American Philosophical Society (1972).
== History == In the late 1950s and early 1960s, the French molecular biologists François Jacob and Jacques Monod became the first to explain enzyme induction, in the context of the lac operon of Escherichia coli. In the absence of lactose, the constitutively expressed lac repressor protein binds to the operator region of the DNA and prevents the transcription of the operon genes. When present, lactose binds to the lac repressor, causing it to separate from the DNA and thereby enabling transcription to occur. Monod and Jacob generated this theory following 15 years of work by them and others (including Joshua Lederberg), partially as an explanation for Monod's observation of diauxie. Previously, Monod had hypothesized that enzymes could physically adapt themselves to new substrates; a series of experiments by him, Jacob, and Arthur Pardee eventually demonstrated this to be incorrect and led them to the modern theory, for which he and Jacob shared the 1965 Nobel Prize in Physiology or Medicine (together with André Lwoff).
Public health laboratories operate as a first line of defense to protect the public against diseases and other health hazards. Day-to-day operations range from testing water and food, checking for toxins in soil, and investigating new strains of infectious diseases, such as COVID-19 or Ebola. Every US state and territory, and the District of Columbia, has a central governmental public health laboratory that performs testing and other laboratory services on behalf of the entire jurisdiction. In addition, some states have local public health laboratories ranging in size from large metropolitan laboratories with over a hundred scientists to small rural laboratories with one or two staff that support local public health.
== Sodium-24 == Sodium-24 is radioactive and is generally created from common sodium-23 by neutron activation. With a half-life of 14.956 hours, 24Na decays to 24Mg by emission of an electron and, almost always, two gamma rays. Exposure of the human body to intense neutron radiation creates 24Na in the blood plasma. Measurements of its quantity can be done to determine the absorbed radiation dose of a patient. This can be used to determine the medical treatment required. When sodium is used as coolant in fast breeder reactors, radioactive 24Na is created within the coolant. When the 24Na decays, magnesium forms and builds up in the coolant. Since the half-life is short, the 24Na portion of the coolant ceases to be radioactive within a few days after removal from the reactor. Leakage of the hot sodium from the primary loop may cause radioactive fires, as it can ignite in contact with air (and explodes in contact with water). For this reason, the primary cooling loop is placed within the containment vessel. Sodium has been proposed as a casing for a salted bomb, as it would convert to 24Na and produce intense gamma-ray emissions for a few days.
Sources: en.wikipedia.org
=== Available biosimilars === As of 2025, there are three commercially available biosimilar insulins. They are insulin glargine-yfgn, insulin glargine-aglr, and insulin aspart-szjj. Insulin glargine-yfgn is marketed under the name Semglee, and received FDA approval in July 2021, but development began before that. The approval was granted to Mylan, which was merged with another company into Viatris in 2020. The second approved biosimilar insulin, insulin glargine-aglr, was approved by the FDA in December 2021 to be produced by Lilly under the name Rezvoglar. In February 2025, the FDA approved the very first short-acting biosimilar insulin, insulin aspart szjj. It is manufactured by Viatris and sold under the name Merilog. It is of note that although the name of insulin lispro-aabc, which is marketed as Lyumjev by Lilly, is similar to the names of biosimilars, it is not a biosimilar insulin. Insulin lispro-aabc is simply a faster formulation of insulin lispro.
The location of the enzyme that links these two parts of gluconeogenesis by converting oxaloacetate to PEP – PEP carboxykinase (PEPCK) – is variable by species: it can be found entirely within the mitochondria, entirely within the cytosol, or dispersed evenly between the two, as it is in humans. Transport of PEP across the mitochondrial membrane is accomplished by dedicated transport proteins; however no such proteins exist for oxaloacetate. Therefore, in species that lack intra-mitochondrial PEPCK, oxaloacetate must be converted into malate or aspartate, exported from the mitochondrion, and converted back into oxaloacetate in order to allow gluconeogenesis to continue.
In 1958, the RCAF retired its 78 remaining Mustangs. RCAF pilot Lynn Garrison ferried them from their various storage locations to Canastota, New York, where the American buyers were based. Garrison flew each of the surviving aircraft at least once. These aircraft make up a large percentage of the aircraft presently flying worldwide. The most prominent firm to convert Mustangs to civilian use was Trans-Florida Aviation, later renamed Cavalier Aircraft Corporation, which produced the Cavalier Mustang. Modifications included a taller tailfin and wingtip tanks. Conversions included a Cavalier Mustang specialty: a "tight" second seat added in the space formerly occupied by the military radio and fuselage fuel tank. In the late 1960s and early 1970s, when the United States Department of Defense wished to supply aircraft to South American countries and later Indonesia for close air support and counterinsurgency, it paid Cavalier to return some of their civilian conversions back to updated military specifications. In the 21st century, a P-51 can command a price of more than $1 million, even for only partially restored aircraft. There were 204 privately owned P-51s in the US on the FAA registry in 2011, most of which are still flying, often associated with organizations such as the Commemorative Air Force (formerly the Confederate Air Force).
In conclusion, it should be kept in mind that scientific research, and the cutting- edge technologies that both drive and are driven by it, are constantly and rapidly evolving. Some of Petsko’s criticisms are constructive, and should be noted by policy-makers. But one should not throw the baby out with the bathwater, rather tune the scope and objectives of the PSI to the needs of the life-science community as a whole, much in the spirit of SPINE, the SGC and other European structural genomics/ proteomics projects. If such a constructive approach is adopted, we feel confident that the structural data provided by the PSI and its cousins will serve as no less valuable a resource than genome sequences. In October 2008 the NIGMS hosted a meeting concerning the future of structural genomics efforts and invited speakers from the PSI Advisory Committee, members of the NIGMS Advisory Council, and interested scientists who had no previous involvement with the PSI. Representatives of other genomics, proteomics, and structural genomics initiatives, as well as scientists from academia, government, and industry were also included. Based on this meeting and the subsequent recommendations from the PSI Advisory Committee, a concept-clearance document was released in January 2009 describing what a third phase of the PSI might entail.
Sources: en.wikipedia.org
==== Low-level laser therapy (LLLT) ==== Low-level laser therapy or photobiomodulation is also referred to as red light therapy and cold laser therapy. It is a non-invasive treatment option. LLLT is shown to increase hair density and growth in both genders. The types of devices (hat, comb, helmet) and duration did not alter the effectiveness, with more emphasis to be placed on lasers compared to LEDs. Ultraviolet and infrared light are more effective for alopecia areata, while red light and infrared light is more effective for androgenetic alopecia. Medical reviews suggest that LLLT is as effective or potentially more than other non invasive and traditional therapies like minoxidil and finasteride but further studies such as RCTs, long term follow up studies, and larger double blinded trials need to be conducted to confirm the initial findings.
Neurapraxia is a temporary interruption of conduction without loss of axonal continuity.[2] Neurapraxia involves a physiologic block of nerve conduction in the affected axons. Neurapraxia is commonly caused by focal demyelination or ischemia, and is a result of damage to the myelin sheath of the nerves. With this injury, the connective tissue structures of the nerve are preserved and the axon remains intact. This injury is generally associated with a favorable prognosis and recovery has occurred within weeks to months. Other characteristics:
This resulted in the publication of the report, The Double Bind: The Price of Being a Minority Woman in Science (1976) which made recommendations for recruiting and retaining minority women scientists. Daly was a member of the board of governors of the New York Academy of Sciences for two years. She was a fellow of the American Association for the Advancement of Science and of the American Cancer Society. Daly was designated as a career scientist by the Health Research Council of the City of New York. Daly retired in 1986 from the Albert Einstein College of Medicine, and in 1988 established a scholarship for African American chemistry and physics majors at Queens College in memory of her father. In 1999, she was recognized by the National Technical Association as one of the top 50 women in Science, Engineering and Technology.
=== October–December 2007: Participatory notes issue === 18,000, 9 October 2007- The SENSEX crossed the 18,000 mark for the first time on 9 October 2007, gaining 788 points, to close at 18,280. The journey from 17,000 to 18,000 took just 8 trading sessions, which is the third fastest 1000-point rise in the history of the SENSEX. 19,000, 15 October 2007- The SENSEX crossed the 19,000 mark for the first time on 15 October 2007, gaining 640 points, to close at 19,059. It took just 4 trading sessions for the SENSEX to move from 18,000 to 19,000. This is the fastest 1000-point rise ever for the index. In addition, the rise from 16,000 to 19,000 in 17 trading sessions sets a record for the fastest 3,000-point rally in the history of the SENSEX. On 16 October 2007, SEBI (Securities & Exchange Board of India) proposed curbs on participatory notes which accounted for roughly 50% of FII investment in 2007. SEBI was not happy with P-notes because it was not possible to know who owned the underlying securities, and hedge funds acting through P-notes might therefore cause volatility in the Indian markets. However the proposals of SEBI were not clear and this led to a knee-jerk crash when the markets opened on the following day (17 October 2007). Within a minute of opening trade, the SENSEX crashed by 1,744 points or about 9% of its value – the biggest intra-day fall in Indian stock markets in absolute terms until then. This led to the automatic suspension of trade for one hour. Finance Minister P.
=== Pharmacokinetics === After being taken by mouth, paracetamol is rapidly absorbed from the small intestine, while absorption from the stomach is negligible. Thus, the rate of absorption depends on stomach emptying. Food slows the stomach's emptying and absorption, but the total amount absorbed stays the same. In the same subjects, the time to reach peak plasma concentration of paracetamol was 20 minutes in a fasting state, compared to 90 minutes in a fed state. Furthermore, a high-carbohydrate meal reduced the peak plasma concentration by approximately fourfold, an effect not observed with high-protein or high-fat meals. Paracetamol's bioavailability is dose-dependent: it increases from 63% for 500 mg dose to 89% for 1000 mg dose. Its plasma terminal elimination half-life is 1.9–2.5 hours, and volume of distribution is roughly 50 L. Protein binding is negligible, except under the conditions of overdose, when it may reach 15–21%. The concentration in serum after a typical dose of paracetamol usually peaks below 30 μg/mL (200 μmol/L). After 4 hours, the concentration is usually less than 10 μg/mL (66 μmol/L).
Sources: en.wikipedia.org
Liquid chromatography-tandem mass spectrometry is a common approach. It can detect the parent compound and its metabolites in biological matrices.
Research samples are typically kept frozen, desiccated, and protected from light. Stock solutions are often aliquoted to reduce freeze-thaw cycles.
High-performance liquid chromatography and nuclear magnetic resonance are standard for purity and identity. Mass spectrometry confirms molecular weight.
No. It is an investigational compound without approved therapeutic indications. It is sold for research purposes only in many jurisdictions.