If you have been reading about circadian clock 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 2026-01-08. Numbers and descriptions here follow the published literature rather than marketing material.
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.
REV-ERB proteins typically suppress gene expression by recruiting corepressor complexes to DNA response elements. SR9009 binds these receptors and strengthens that repressive action in cell-based assays. Studies in rodents have reported changes in lipid handling, mitochondrial function, and exercise capacity after treatment. Such findings are often cited as evidence for metabolic effects, but species differences and limited pharmacokinetic data make direct translation to humans uncertain. Researchers continue to examine which effects are robust and which depend on specific experimental conditions.
Physicochemical behavior influences handling. SR9009 is described as a solid with limited aqueous solubility, so organic solvents such as dimethyl sulfoxide or ethanol are common in research stock solutions. Aqueous dilution can produce precipitates if the organic content is too low. Light, heat, and repeated freeze-thaw cycles may affect stability. Storage recommendations usually specify a desiccated freezer environment protected from light, but exact stability data depend on the formulation and matrix.
Detection in biological samples can be complicated by rapid metabolism and low circulating concentrations. Some studies report phase I and phase II metabolites, and analytical methods may need to target those species in addition to the parent compound. Immunoassays are not broadly available, so mass spectrometry remains the main confirmatory approach. For anti-doping testing, laboratories look for SR9009 and its metabolites using validated LC-MS methods. Open questions include how long metabolites remain detectable and how different routes of administration alter detection windows.
In laboratory settings, SR9009 is typically characterized by liquid chromatography–mass spectrometry (LC-MS) or high-performance liquid chromatography with ultraviolet detection (HPLC-UV). These methods can confirm identity and estimate purity, but they require reference standards for accurate quantification. Because SR9009 is not a licensed pharmaceutical, no harmonized pharmacopeial monograph exists. Laboratories often validate in-house methods for matrices such as plasma, urine, or cell culture media. Sample preparation may involve protein precipitation or liquid-liquid extraction before analysis.
| Property | Value | Notes |
|---|---|---|
| Common name | SR9009 | Also marketed informally as Stenabolic |
| Chemical class | Synthetic REV-ERB agonist | Binds REV-ERBα and REV-ERBβ |
| Molecular formula | C24H30ClN3O4S | Approximate molecular weight 492 g/mol |
| CAS Registry Number | 1379686-30-2 | Identifier for the parent compound |
| Regulatory status | Not approved for human use | Prohibited in sport by WADA |
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is not an approved medicine and has no established human therapeutic use. The compound appears in scientific literature as a tool for probing circadian and metabolic regulation. Online sellers often label it as a research chemical, sometimes using the nickname Stenabolic. Its chemical identity is distinct from selective androgen receptor modulators, stimulants, and peroxisome proliferator-activated receptor delta agonists. Researchers use it mainly in cell and animal experiments.
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.
Blood or urine tests measure hCG. These can be pregnancy tests. hCG-positive can indicate an implanted blastocyst and mammalian embryogenesis or can be detected for a short time following childbirth or pregnancy loss. Tests can be done to diagnose and monitor germ cell tumors and gestational trophoblastic diseases. Concentrations are commonly reported in thousandth international units per milliliter (mIU/mL). The international unit of hCG was originally established in 1938 and has been redefined in 1964 and in 1980. At the present time, 1 international unit is equal to approximately 2.35×10−12 moles, or about 6×10−8 grams. It is also possible to test for hCG to have an approximation of the gestational age.
Carbon-14 (also called radiocarbon) occurs in trace amounts and has a half-life of 5730 years. The primary source of 14C on Earth is the reaction of 14N with thermal neutrons from cosmic radiation spallation reactions in the upper atmosphere; this mixes throughout the atmosphere, and biological processes such as photosynthesis incorporate the 14C into living organisms. Since organisms stop absorbing 14C upon dying, measurement of the amount of 14C in a sample may be used to estimate its age. This technique, called radiocarbon dating, is one of the principal methods of radiometric dating in archaeology.
== Mechanism of action == Glipizide sensitizes the beta cells of pancreatic islets of Langerhans insulin response, meaning that more insulin is released in response to glucose than would be without glipizide ingestion. Glipizide acts by partially blocking potassium channels among beta cells of pancreatic islets of Langerhans. By blocking potassium channels, the cell depolarizes, which results in the opening of voltage-gated calcium channels. The resulting calcium influx encourages insulin release from beta cells.
For example, for an amino acid sequence (there are 20 "standard" amino acids that make up proteins), you would find there are 208 parameters. However, when studying coding regions of the genome, it is more common to work with a codon substitution model (a codon is three bases and codes for one amino acid in a protein). There are
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Plasma renin activity (PRA), also known as the renin (active) assay or random plasma renin, is a measure of the activity of the plasma enzyme renin, which plays a major role in the body's regulation of blood pressure, thirst, and urine output. Measure of direct renin concentration (DRC) is technically more demanding, and hence PRA is used instead. DRC assays are still in evolution, and generally a conversion factor of PRA (ng/mL/h) to DRC (mU/L) is 8.2. A recently developed and already commonly used automated DRC assay uses the conversion factor of 12. PRA is sometimes measured, specially in case of certain diseases which present with hypertension or hypotension. PRA is also raised in certain tumors. A PRA measurement may be compared to a plasma aldosterone concentration as an aldosterone-to-renin ratio (ARR).
The mechanism of action of bupropion in the treatment of depression and for other indications is unclear. However, it is thought to be related to the fact that bupropion is a norepinephrine–dopamine reuptake inhibitor (NDRI) and negative allosteric modulator of several nicotinic acetylcholine receptors. Bupropion does not act as a norepinephrine–dopamine releasing agent. Pharmacological actions of bupropion, to a substantial degree, are due to its active metabolites hydroxybupropion, threo-hydrobupropion, and erythro-hydrobupropion that are present in the blood plasma at comparable or much higher levels. In fact, bupropion could accurately be conceptualized as a prodrug of these metabolites. The overall action of these metabolites, particularly that of one enantiomer, S,S-hydroxybupropion, is also characterized by inhibition of norepinephrine and dopamine reuptake and nicotinic inhibition (see the chart on the right). Bupropion has no meaningful direct activity at a variety of receptors, including α- and β-adrenergic, dopamine, serotonin, histamine, and muscarinic acetylcholine receptors. The occupancy of dopamine transporter (DAT) by bupropion (300 mg/day) and its metabolites in the human brain as measured by several positron emission tomography (PET) studies is approximately 20%, with a mean occupancy range of about 14 to 26%. For comparison, the NDRI methylphenidate at therapeutic doses is thought to occupy greater than 50% of DAT sites.
=== A. tumefaciens === Production of siderophores also exhibited in some plant-infecting bacteria, such as Agrobacterium tumefaciens. The enzyme is controlled by gene cluster agb and the production of 2,3-diDHB dehydrogenase is controlled by the gene agbA. The enzyme AgbA is homologous to the EntA enzyme in E. coli, the same enzyme that produces 2,3-diDHB dehydrogenase.
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== Covalent perchlorates == Although typically found as a non-coordinating anion, a few metal complexes are known. Hexaperchloratoaluminate and tetraperchloratoaluminate are strong oxidising agents. Several perchlorate esters are known. For example, methyl perchlorate is a high energy material that is a strong alkylating agent. Chlorine perchlorate is a covalent inorganic analog.
=== Nomenclature === In order to categorize a mutation as such, the "normal" sequence must be obtained from the DNA of a "normal" or "healthy" organism (as opposed to a "mutant" or "sick" one), it should be identified and reported; ideally, it should be made publicly available for a straightforward nucleotide-by-nucleotide comparison, and agreed upon by the scientific community or by a group of expert geneticists and biologists, who have the responsibility of establishing the standard or so-called "consensus" sequence. This step requires a tremendous scientific effort. Once the consensus sequence is known, the mutations in a genome can be pinpointed, described, and classified. The committee of the Human Genome Variation Society (HGVS) has developed the standard human sequence variant nomenclature, which should be used by researchers and DNA diagnostic centers to generate unambiguous mutation descriptions. In principle, this nomenclature can also be used to describe mutations in other organisms. The nomenclature specifies the type of mutation and base or amino acid changes.
=== Posthumous assessment === International reactions to Gaddafi's death were divided. Gaddafi was mourned as a hero by many across sub-Saharan Africa but was condemned as a brutal dictator in many Western nations. After his defeat in the civil war, Gaddafi's system of governance was dismantled and replaced by the interim government of the NTC, which legalized trade unions and freedom of the press. In January 2013, the GNC officially renamed the Jamahiriyah as the "State of Libya". Gaddafi loyalists then founded a new political party, the Popular Front for the Liberation of Libya. Led by Saif al-Islam Gaddafi, the Popular Front was allowed to participate in the future general election.
The two substrates of this enzyme are precorrin-2 and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are sirohydrochlorin, reduced NADH, and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is precorrin-2:NAD+ oxidoreductase. Other names in common use include Met8p, SirC, and CysG. This enzyme is part of the biosynthetic pathway to cobalamin (vitamin B12) in anaerobic bacteria and to Cofactor F430.
Sources: en.wikipedia.org
SR9009 is a synthetic research compound that binds and modulates the nuclear receptors REV-ERBα and REV-ERBβ. It is used in laboratory studies of circadian biology and metabolism, not as an approved medicine. It is also known by the informal name Stenabolic.
No. SR9009 has not been approved as a therapeutic drug in the United States, European Union, or other major markets. Human safety and efficacy data are very limited. Its presence in consumer products does not imply regulatory approval.
The World Anti-Doping Agency lists SR9009 as a prohibited substance because it can alter gene expression and metabolic pathways relevant to performance. The ban applies at all times, not only during competition. Detection relies on laboratory methods such as mass spectrometry.
It is usually detected by LC-MS or HPLC-UV against a reference standard. In biological matrices, metabolite targeting can improve detection. No universal immunoassay is widely available.