A practical reference on nuclear receptor: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-09-30. Anything still debated is marked as such rather than presented as settled.
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 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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic small molecule | Studied as a REV-ERB agonist |
| Molecular formula | C20H24ClN3O4S | Reported for the neutral compound |
| Appearance | Off-white to pale yellow solid | Typical research-grade material |
| Solubility | Sparingly soluble in water | Soluble in solvents such as DMSO |
| Common synonyms | SR9009; Stenabolic | Stenabolic is an informal alias |
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.
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.
Laboratory samples of SR9009 are typically handled as research chemicals rather than pharmaceuticals. Suppliers usually state that the material is for research use only and not for human or veterinary administration. Storage recommendations generally call for a freezer at approximately −20 °C, protection from light, and a desiccated environment. The solid is often described as a white to off-white powder. Solubility is commonly reported in organic solvents such as dimethyl sulfoxide and ethanol, with low solubility in water.
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.
== History == In 1968, Josef Pacák, Zdeněk Točík, and Miloslav Černý at the Department of Organic Chemistry, Charles University, Czechoslovakia were the first to describe the synthesis of FDG. Later, in the 1970s, Tatsuo Ido and Al Wolf at the Brookhaven National Laboratory were the first to describe the synthesis of FDG labeled with fluorine-18. The compound was first administered to two human volunteers by Abass Alavi in August 1976 at the University of Pennsylvania. Brain images obtained with an ordinary (non-PET) nuclear scanner demonstrated the concentration of [18F]FDG in that organ (see history reference below). Beginning in August 1990, and continuing throughout 1991, a shortage of oxygen-18, a raw material for FDG, made it necessary to ration isotope supplies. Israel's oxygen-18 facility had shut down due to the Gulf War, and the U.S. government had shut down its isotopes of carbon, oxygen and nitrogen facility at Los Alamos National Laboratory, leaving Isotec as the main supplier.
== Pharmacology == Teneligliptin has unique J-shaped or anchor locked domain structure because of which it has a potent inhibition of DPP 4 enzyme. Teneligliptin significantly controls glycemic parameters with safety. No dose adjustment is required in renally impaired patients.
==== Salamanders (Urodela) ==== Clade Salamandroidea Family Salamandridae Pleurodeles waltl, Iberian ribbed newt, (2025) Triturus cristatus, great crested newt (2025) Family Ambystomatidae (Tiger Salamanders) Ambystoma mexicanum, Axolotl (2018)
Sources: en.wikipedia.org
Aprepitant, sold under the brand name Emend among others, is a medication used to prevent chemotherapy-induced nausea and vomiting and to prevent postoperative nausea and vomiting. It may be used together with ondansetron and dexamethasone. It is taken by mouth or administered by intravenous injection. A prodrug, fosaprepitant, is also available for intravenous administration. Common side effects include tiredness, loss of appetite, diarrhea, abdominal pain, hiccups, itchiness, pneumonia, and blood pressure changes. Other severe side effects may include anaphylaxis. While use in pregnancy does not appear to be harmful, such use has not been well studied. Aprepitant belongs to the class of neurokinin-1 receptor antagonists. It works by blocking substance P from attaching to the NK1 receptors. Aprepitant was approved for medical use in the European Union and the United States in 2003. It is made by Merck & Co. It is on the World Health Organization's List of Essential Medicines.
==== Antibody-dependent cell-mediated cytotoxicity (ADCC) ==== Antibody-dependent cell-mediated cytotoxicity (ADCC) requires antibodies to bind to target cell surfaces. Antibodies are formed of a binding region (Fab) and the Fc region that can be detected by immune system cells via their Fc surface receptors. Fc receptors are found on many immune system cells, including NK cells. When NK cells encounter antibody-coated cells, the latter's Fc regions interact with their Fc receptors, releasing perforin and granzyme B to kill the tumor cell. Examples include rituximab, ofatumumab, elotuzumab, and alemtuzumab. Antibodies under development have altered Fc regions that have higher affinity for a specific type of Fc receptor, FcγRIIIA, which can dramatically increase effectiveness.
Orbital Hubs – A Culture Orbital is a smaller version of a ringworld, with large numbers of people living on the inside surface of them, in a planet-like environment. Rocks – Minds in charge of planetoid-like structures, built/accreted, mostly from the earliest times of the Culture before it moved into space-built orbitals. Stores – Minds of a quiet temperament run these asteroids, containing vast hangars, full of mothballed military ships or other equipment. Some 'Rocks' also act as 'Stores'. University Sages – Minds that run Culture universities / schools, a very important function as every Culture citizen has an extensive education and further learning is considered one of the most important reasons for life in the Culture. Atypical Minds Eccentric – Culture Minds who have become "... a bit odd" (as compared to the very rational standards of other Culture Minds). Existing at the fringe of the Culture, they can be considered (and consider themselves) as somewhat, but not wholly part of the Culture. Sabbaticaler – Culture Minds who have decided to abdicate from their peer pressure-based duties in the Culture for a time. Ulterior – Minds of the Culture Ulterior, an umbrella term for all the no-longer-quite-Culture factions. Converts – Minds (or sentient computers) from other societies who have chosen to join the Culture. Absconder – Minds who have completely left the Culture, especially when in doing so having deserted some form of task.
=== Interactions === Care should be exercised by people who are also taking protease inhibitors for the treatment of HIV infection. Protease inhibitors inhibit the metabolism of sildenafil, effectively multiplying the plasma levels of sildenafil, increasing the incidence and severity of side effects. Those using protease inhibitors are recommended to limit their use of sildenafil to no more than one 25 mg dose every 48 hours. Other drugs that interfere with the metabolism of sildenafil include erythromycin and cimetidine, both of which can also lead to prolonged plasma half-life levels. The use of sildenafil and an α1 blocker (typically prescribed for hypertension or for urologic conditions, such as benign prostatic hypertrophy) at the same time may lead to low blood pressure, but this effect does not occur if they are taken at least 4 hours apart.
Sources: en.wikipedia.org
The quantitative "reading" is usually based on detection of intensity of transmitted light by spectrophotometry, which involves quantitation of transmission of some specific wavelength of light through the liquid (as well as the transparent bottom of the well in the multiple-well plate format). The sensitivity of detection depends on amplification of the signal during the analytic reactions. Since enzyme reactions are very well known amplification processes, the signal is generated by enzymes which are linked to the detection reagents in fixed proportions to allow accurate quantification, and thus the name "enzyme-linked". The analyte is also called the ligand because it will specifically bind or ligate to a detection reagent, thus ELISA falls under the bigger category of ligand binding assays. The ligand-specific binding reagent is "immobilized", i.e., usually coated and dried onto the transparent bottom and sometimes also side wall of a well (the stationary "solid phase"/"solid substrate" here as opposed to solid microparticle/beads that can be washed away), which is usually constructed as a multiple-well plate known as the "ELISA plate". Conventionally, like other forms of immunoassays, the specificity of antigen-antibody type reaction is used because it is easy to raise an antibody specifically against an antigen in bulk as a reagent. Alternatively, if the analyte itself is an antibody, its target antigen can be used as the binding reagent.
It is not understood whether the physical opening of the L-type calcium channels or the presence of calcium causes the ryanodine receptors to open. The outflow of calcium allows the myosin heads access to the actin cross-bridge binding sites, permitting muscle contraction. Muscle contraction ends when calcium ions are pumped back into the sarcoplasmic reticulum, allowing the contractile apparatus and, thus, muscle cell to relax. Upon muscle contraction, the A-bands do not change their length (1.85 micrometer in mammalian skeletal muscle), whereas the I-bands and the H-zone shorten. This causes the Z-lines to come closer together.
Three of the entrances took the form of free-standing pavilions or small stations, including waiting rooms: one at Bastille and two on Avenue de Wagram at Étoile. These were in a style influenced by Japanese pagodas. At Étoile Guimard provided exterior doors for elevators, although the elevators were not built. Eight simpler but still elaborate structures, labeled "Édicule B" by Guimard, were installed at the termini of Line 1 as originally opened and at two other major stations. These consisted of three-sided glass-roofed structures enclosing the stairway, with a projecting canopy. A variation on this format, "Édicule A", lacked the canopy and was erected at two stations, Saint-Paul and Reuilly–Diderot. These édicule types of entrance, which have come to be called libellules because they resemble dragonflies, in some cases had decorated wall panels surfaced in reconstituted lava. The great majority of the entrances built (154) were unroofed enclosures, dubbed an entourage. A transitional form between the entourage and the édicule, railings with a roof and canopy, was used for one entrance at the Gare de Lyon metro station. At many of the entourages, the top of the steps is surmounted by a "Métropolitain" or "Métro" sign in a holder that extends between two risers in the form of sinuous stalks, traditionally compared to lily of the valley (brin de muguet), each bearing a light in the form of a red-orange globe reminiscent of an eye or a flower.
Sources: en.wikipedia.org
SR9009 is a synthetic research compound that activates the REV-ERBα and REV-ERBβ nuclear receptors. It is not an approved drug and has no established human therapeutic use. Most published biological data come from cell and rodent studies.
No. SR9009 is frequently mislabeled as a SARM in online discussions, but it does not target androgen receptors. Its known mechanism involves REV-ERB nuclear receptors and circadian-metabolic gene regulation.
Human clinical data are very limited. There is no approved human use, and safety and efficacy in people are not established. Most evidence comes from preclinical models, so effects observed in animals may not apply to humans.
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.