This is a working overview of circadian rhythm, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-11-09. Anything still debated is marked as such rather than presented as settled.
At the molecular level, SR9009 binds REV-ERBα and REV-ERBβ and alters their repressive activity on target genes. These nuclear receptors help regulate the circadian clock, lipid synthesis, glucose metabolism, and inflammatory pathways. By changing transcription, the compound can shift the timing or magnitude of downstream metabolic processes in model systems. It does not act through androgen receptors or adenosine receptors, which distinguishes it from several substances sold for athletic performance. Whether the same transcriptional changes occur in humans at tolerable exposures remains an open question because controlled human studies are lacking.
Preclinical reports describe effects on exercise endurance, mitochondrial content, and lipid profiles in rodents, but these findings come from specific experimental conditions. Many studies use high doses or delivery methods that may not translate directly to human use. SR9009 has been reported to have low oral bioavailability and a short half-life, which complicates interpretation of oral dosing studies. It is not established as safe or effective for any indication. Literature discussions often separate its pharmacological mechanism from unverified claims made in fitness and supplement markets.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C20H24ClN3O4S | Derived from published structure. |
| Molecular weight | 437.94 g/mol | Calculated value. |
| Appearance | White to off-white solid | Typical for purified research samples. |
| Solubility | DMSO, ethanol; low in water | Class: poorly water-soluble. |
| Typical storage | -20 °C, desiccated, protected from light | Limits degradation. |
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.
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.
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.
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 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.
Mechanistically, SR9009 binds the ligand-binding domain of REV-ERBα/β and enhances recruitment of corepressor complexes. This represses target genes rather than activating them. Because REV-ERB proteins normally compete with ROR proteins at shared response elements, the net effect depends on tissue and timing. Researchers use SR9009 to probe how nuclear receptor signaling links the clock to metabolism, inflammation, and muscle biology. Findings are largely preclinical, and the precise contribution of each receptor subtype remains under study.
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.
== Mechanism of action == Ro65-6570 is an opioid drug, it works by activating opioid receptors. However, instead of acting at the mu, kappa and delta receptors, it is instead an agonist at the nociceptin receptor.
== Double meaning == The use of the word "faggot" has caused misunderstanding due to its meaning as a pejorative term for a homosexual man. In 2004, a radio commercial for the UK supermarket chain Somerfield, in which a man rejects his wife's suggested dinner saying "I've got nothing against faggots, I just don't fancy them" was found to have been innuendo which breached the Advertising and Sponsorship Code and was banned by the industry regulator Ofcom. Additionally, the term caused multiple instances of the scunthorpe problem, where profanity filters erroneously blocked the term regardless of its use in context. In November 2013, it was reported that British Facebook users had been blocked temporarily for using the word, in its culinary sense, on the website. Facebook said that the word had been misinterpreted. In September 2019, a Google Ads advertisement for a British cafe was removed for featuring the term.
An allergy is an exaggerated immune response where the body mistakenly identifies an ordinarily harmless allergen as a threat. Allergic reactions give rise to allergic diseases such as hay fever, allergic conjunctivitis, allergic asthma, atopic dermatitis, food allergies, and anaphylaxis. Symptoms of allergic diseases may include red eyes, an itchy rash, sneezing, coughing, a runny nose, shortness of breath, or swelling. Common allergens include pollen, certain foods, metals, insect stings, medications, and materials, such as latex. The development of allergies is due to genetic and environmental factors. The mechanism of allergic reactions involves immunoglobulin E antibodies (IgE) binding to an allergen and then to a receptor on mast cells or basophils, where they trigger the release of inflammatory chemicals such as histamine. Diagnosis is typically based on a person's medical history. Further testing of the skin or blood may be useful in certain cases. Positive tests, however, may not necessarily mean there is a significant allergy to the substance in question. Early exposure of children to potential allergens may be protective. Treatments for allergies include avoidance of known allergens and the use of medications such as steroids and antihistamines. In severe reactions, injectable adrenaline (epinephrine) is recommended. Allergen immunotherapy, which gradually exposes people to larger and larger amounts of allergen, is useful for some types of allergies such as hay fever and reactions to insect bites. Its use in food allergies is unclear. Allergies are common.
Sources: en.wikipedia.org
=== Availability === The "reference" version of BLOSUM is found in the NCBI toolkits. Both the older (deprecated) NCBI C Toolkit and the current NCBI C++ Toolkit provide the BLOSUM45, BLOSUM50, BLOSUM62, BLOSUM80, and BLOSUM90 matrices. Both also offer APIs for making use of the matrices. The original source code for calculating BLOSUM is also found on the NCBI website, at https://ftp.ncbi.nih.gov/repository/blocks/unix/blosum/. This archive "blosum.tar.Z" represents the original miscalculated version with improved search performance from 1992. The archive also contains pre-calculated BLOSUM outputs at the following similarity levels: "-2" (blosumn), 30, 40, 45, 50, 55, 60, 62, 65, 70, 75, 80, 85, 90, 95, and 100.
On 11 December 1944, the unit was again renamed, becoming 309 Dywizjon Myśliwski "Ziemi Czerwieńskiej" or 309 "Land of Czerwien" Polish Fighter Squadron. In 1945, 303 "Kościuszko" Sqn received 20 Mustangs Mk IV/Mk IVA replacements. Postwar, between 6 December 1946 and 6 January 1947, all five Polish squadrons equipped with Mustangs were disbanded. Poland returned about 80 Mustang Mk IIIs and 20 Mustangs Mk IV/IVAs to the RAF, which transferred them to the US government. Somalia The Somali Air Force operated eight P-51Ds in post-World War II service. South Africa
Carl Ronald Kahn (born January 14, 1944) is an American physician and scientist, best known for his work with insulin receptors and insulin resistance in diabetes and obesity. He is the Chief Academic Officer at Joslin Diabetes Center, the Mary K. Iacocca Professor of Medicine at Harvard Medical School and a member of the National Academy of Sciences since 1999.
=== Cosmetics and medicine === In nutraceutical industries, Arthrospira (Spirulina) and Chlorella are the most important species in commercialization as health foods and nutrition supplements with various health benefits including enhancing immune system activity, anti-tumor effects, and animal growth promotion, due to their abundant proteins, vitamins, active polysaccharides, and other important compounds. Microalgal carotenoids, with β-carotene from Dunaliella and astaxanthin from Haematococcus are commercially produced in large scale processes. Microalgal derived products are currently successfully developed for uses in cosmetics and pharmaceutical products. Examples include the polysaccharides from cyanobacteria used in personal skin care products and extracts of Chlorella sp. which contain oligopeptides that can promote firmness of the skin. In the pharmaceutical industries drug candidates with anti-inflammatory, anticancer, and anti-infective activities have been identified. For instance, adenosine from Phaeodactylum tricornutum, can act as an anti-arrhythmic agent for the treatment of tachycardia and the green algal metabolite caulerpin is featured in studies of anti-tuberculosis activities. Moreover, some extracellular polysaccharides from microalgae have various bioactivities involving antitumor, anti-inflammatory, and antiviral activity, providing promising prospects for pharmaceutical applications.
Sources: en.wikipedia.org
=== Electrospray ionization mass spectrometry === Electrospray ionization mass spectrometry is a very versatile technique, consisting in a transfer of the formed complexes from the injected solution to the gas phase by a soft ionization process without strongly perturbing the complex stability. In addition, a small amount of the prepared solution needs to be injected to obtain the speciation spectra. Speciation of several metal ions can be investigated in monophasic solutions at increasing ligand concentration in order to explore all potential complexes. Collision Induced Dissociation (CID) analysis can be also performed to assess the kinetic stability of the formed complexes by discovering the main fragmentation pathway of the ligand. Besides, the protonation effect on the complexation mechanism can be observed by performing analysis on monophasic solutions at increasing nitric acid concentration. Corroboration of the major complexes involved into the extraction process is generally found by performing experiments on biphasic solutions upon extraction tests. Despite versatility of this spectroscopic technique that directly provides information by changing the ligand to metal ratios, its qualitative nature due to instrumental set-up and potential changes in solution chemistry could partially affect species distribution and its ion abundance. For these reasons, corroboration for the speciation results needs to be found by other spectroscopic techniques.
On the basis of Gennaro's histological studies and the present amino acid and Cu and Fe analyses, I conclude that, to the extent the preserved O. giganteus tissue is representative of the carcass washed ashore at St. Augustine, Florida, in November 1896, it was essentially a huge mass of collagenous protein. Certainly, the tissue was not blubber. I interpret these results as consistent with, and supportive of, Webb and Verrill's identification of the carcass as that of a gigantic cephalopod, probably an octopus, not referable to any known species.
. The Burnett equations include additional second-order derivatives of velocity, temperature, and density, representing more subtle effects of non-equilibrium gas dynamics. The Burnett equations can be expressed as:
Sources: en.wikipedia.org
SR9009 is a synthetic REV-ERB agonist used in laboratory research. It is not an approved drug, and its effects in humans are not well characterized. It is often sold as a research chemical under the name Stenabolic.
No. SR9009 targets the nuclear receptors REV-ERBα and REV-ERBβ, not the androgen receptor. This mechanism differs from selective androgen receptor modulators and from exercise mimetics that act on PPARδ.
Published evidence is mainly preclinical, using cell cultures and animal models. Controlled human trials are not well documented in the public literature. Claims about human performance or health effects therefore remain unsupported by robust clinical data.
SR9009 is a synthetic small molecule studied as an agonist of the REV-ERB nuclear receptors. It is not an approved medicine, and its effects in humans are not well characterized.