Everything below concerns circadian rhythm. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-01-11. Where a claim depends on a specific study, the study is described rather than over-claimed.
Identity and purity of SR9009 samples are usually checked with chromatographic and spectrometric methods. High-performance liquid chromatography can separate the compound from related impurities, while mass spectrometry provides molecular mass confirmation. Nuclear magnetic resonance spectroscopy may be used for structural verification in research settings. No single method proves biological activity, and certificates of analysis should be reviewed alongside raw data. Independent testing is often needed because online products vary widely.
SR9009 stability depends on temperature, moisture, light, and solvent. Solid material is generally kept cool and dry, while solutions may require protection from repeated warming and cooling. Degradation can appear as color changes, precipitate, or new chromatographic peaks. Researchers should follow supplier instructions and their own stability data. Long-term storage conditions for human use have not been established because the compound lacks approved clinical formulation.
SR9009 is supplied as a solid research chemical, often in milligram quantities. Laboratories typically weigh it in a controlled environment because fine powders can disperse. Stock solutions are commonly prepared in dimethyl sulfoxide and stored in small aliquots to reduce freeze-thaw cycles. Personal protective equipment and chemical fume hoods are standard when handling unknown or potent compounds. These practices address laboratory safety rather than human use.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Synonyms | SR9009; Stenabolic | Stenabolic is an informal name |
| Common form | Crystalline powder | Supplied in milligram to gram quantities |
| Long-term storage | -20 °C, desiccated, protected from light | Reduces degradation |
| Detection technique | LC-MS/MS | Common in anti-doping and research analysis |
| Regulatory status | Prohibited in sport by WADA | Not approved for human therapeutic use |
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.
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.
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.
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.
=== Evolution === The ancestors of American black bears and Asian black bears diverged from sun bears 4.58 mya. The American black bear then split from the Asian black bear 4.08 mya. A small, primitive bear genus called protarctos (U. abstrusus) is the oldest known North American fossil member of the genus Ursus, dated to 4.95 mya. This suggests that U. abstrusus may be the direct ancestor of the American black bear, which evolved in North America. The earliest American black bear fossils, from the Early Pleistocene of Port Kennedy, Pennsylvania, greatly resemble the Asian species, though later specimens grew to sizes comparable to grizzly bears. Once described as a precursor species (Ursus vitabilis), these specimens have been synonymized with U. americanus. The American black bear lived during the same period as the giant and lesser short-faced bears (Arctodus simus and A. pristinus, respectively) and the Florida spectacled bear (Tremarctos floridanus). These tremarctine bears evolved from bears that had emigrated from Asia to the Americas 7–8 mya. The giant and lesser short-faced bears are thought to have been heavily carnivorous and the Florida spectacled bear more herbivorous, while the American black bears remained arboreal omnivores, like their Asian ancestors. From the Holocene to the present, American black bears seem to have shrunk in size, but this has been disputed because of problems with dating these fossil specimens.
=== RIPA (RadioImmunoPrecipitation Assay) lysis buffer === RIPA buffer is a commonly used lysis buffer for immunoprecipitation and general protein extraction from cells and tissues. The buffer can be stored without vanadate at 4 °C for up to 1 year. RIPA buffer releases proteins from cells as well as disrupts most weak interactions between proteins. Recipe:
== Data Utility == Differential refractometers are often used for the analysis of polymer samples in size exclusion chromatography. Other types of information that can be gathered from differential refractometers are:
However, market observers have suggested the pushback from central bankers, professional economists, and congressional Republicans may have led many investors to conclude that the investigation probably will not lead to a long-term shift in the central bank's independence. Powell could remain the Federal Reserve Chair if the United States Senate does not confirm a replacement while Powell's term as a Federal Reserve Governor does not expire until 2028, and some observers have suggested that Powell may choose to serve the entire term to help preserve the central bank's independence—like Federal Reserve Chair Marriner Eccles did after President Harry S. Truman declined to reappoint Eccles as chair in 1948 and led to the Federal Reserve's 1951 Accord with the Treasury Department. Powell has not publicly commented on whether he will do so or not. Additionally, many legal commentators reportedly expect the U.S. Supreme Court to rule against the Trump administration in the lawsuit over the attempted removal of Federal Reserve Governor Lisa Cook in light of a ruling the Court issued the previous year and the oral arguments the Court held on January 21, 2026.
==== Antisense oligomer delivery ==== Antisense oligonucleotides (asONs) have been used in basic research and are being developed as possible medical treatments. CPP strategies have been developed to deliver antisense oligomers such as PNA and PMO into cells. Overcoming the repulsion by the cell membrane of negative-charged ONs and the degradation of asONs by enzymes, CPPs increase asONs bioavailability. Two types of neutral ON analogues, peptide nucleic acid (PNA) and phosphorodiamidate morpholino oligomers (PMO or Morpholino) are becoming dominant in this area. PNA has been conjugated with various CPPs either through disulfide linkages or through stable amide bonds. For example, antisense activity within cells that blocked expression of the galanin receptor was observed when a 21-mer PNA was coupled to the penetratin. Results on antiviral activity with PNA targeting HIV-1 have also been reported through disulfide linkage with TAT. CPP-PMO conjugates have also been successfully used to inhibit the replication of several viruses such as SARS and influenza and attachment of CPPs has improved the efficacy of splice-modifying Morpholinos in development for treatment of Duchenne muscular dystrophy
Sources: en.wikipedia.org
CRF, produced in the PVN, activates CRF1 receptors and CRF2 receptors distributed across limbic circuits. CRF1 receptor activation, which mediates rapid and intense stress responses, triggers acute dynorphin release in limbic stress-responsive regions including the NAcc, basolateral amygdala, dorsal raphe nucleus (DRN), hippocampus, and bed nucleus of the stria terminalis (BNST). CRF2 receptor activation, generally associated with slower, later-phase stress response components, also induces dynorphin-dependent aversive responses such as conditioned place aversion (CPA). Subsequently dynorphin activates KORs expressed on GABAergic and dopaminergic neurons, encoding the aversive and dysphoric qualities of stress exposure. Acutely stress-induced dynorphin release and KOR activation have evolutionarily adaptive functions. KOR-mediated analgesia facilitates physical escape responses to threat, and concurrent KOR-induced dysphoria and aversion promote avoidance and active coping. However, during the delayed temporal phase following acute stress exposure (hours to days), stress-induced KOR signaling initiates intracellular signaling cascades including p38 MAPK and extracellular signal-regulated kinases (ERK) which phosphorylate transcription factors such as cAMP response element-binding protein (CREB) and alter dynorphin and KOR gene expression itself, establishing a self-amplifying cycle.
On 26 August 1807, Bavaria introduced a similar measure. Baden followed in 1809, Prussia in 1815, Württemberg in 1818, Sweden in 1816, England in 1867 and the German Empire in 1874 through the Reichs Vaccination Act. In Lutheran Sweden, the Protestant clergy played a pioneering role in voluntary smallpox vaccination as early as 1800. The first vaccination was carried out in Liechtenstein in 1801, and from 1812 it was mandatory to vaccinate. The question of who first tried cowpox inoculation/vaccination cannot be answered with certainty. Most, but still limited, information is available for Benjamin Jesty, Peter Plett and John Fewster. In 1774 Jesty, a farmer of Yetminster in Dorset, observing that the two milkmaids living with his family were immune to smallpox, inoculated his family with cowpox to protect them from smallpox. He attracted a certain amount of local criticism and ridicule at the time then interest waned. Attention was later drawn to Jesty, and he was brought to London in 1802 by critics jealous of Jenner's prominence at a time when he was applying to Parliament for financial reward. During 1790–92 Peter Plett, a teacher from Holstein, reported limited results of cowpox inoculation to the Medical Faculty of Kiel University. However, the Faculty favoured variolation and took no action. John Fewster, a surgeon friend of Jenner's from nearby Thornbury, discussed the possibility of cowpox inoculation at meetings as early as 1765. He may have done some cowpox inoculations in 1796 at about the same time that Jenner vaccinated Phipps.
== Mechanism of action == Ethacrynic acid acts by inhibiting NKCC2 in the thick ascending loop of Henle and the macula densa. Loss of potassium ions is less marked but chances of hypochloremic alkalosis are greater. The dose response curve of ethacrynic acid is steeper than that of furosemide and, in general, it is less manageable; dose range is 50–150 mg. Ethacrynic acid and its glutathione-adduct are potent inhibitors of glutathione S-transferase family members, which are enzymes involved in xenobiotic metabolism. This family of enzymes has been shown to have a high rate of genetic variability.
John D. Rockefeller Sr. first conceived the idea of the foundation in 1901. In 1906, Rockefeller's business and philanthropic advisor, Frederick Taylor Gates, encouraged him toward "permanent corporate philanthropies for the good of Mankind" so that his heirs should not "dissipate their inheritances or become intoxicated with power." In 1909 Rockefeller signed over 73,000 Standard Oil shares worth $50 million, to his son, Gates and Harold Fowler McCormick as the third inaugural trustee, in the first installment of a projected $100 million endowment. The nascent foundation applied for a federal charter in the US Senate in 1910, with at one stage Junior even secretly meeting with President William Howard Taft, through the aegis of Senator Nelson Aldrich, to hammer out concessions. However, because of the ongoing (1911) antitrust suit against Standard Oil at the time, along with deep suspicion in some quarters of undue Rockefeller influence on the spending of the endowment, the result was that Senior and Gates withdrew the bill from Congress in order to seek a state charter from New York.
=== Current Applications === Voltage gated sodium channels have been used as therapeutic targets in various modes of research, allowing versutoxin to also be used in the process. Some notable diseases versutoxin has been used as a potential therapeutic tool in include: Alzheimer's disease, Parkinson's disease, brain ischemia, glaucoma, and sclerosis. Versutoxin has also been used in biopesticide research. The structure of recombinant Nemertide α-1 (a neurotoxin found in carnivorous marine ribbon worms) was compared against recombinant delta-hexatoxin-Hv1 due to their similar VSGC targeting abilities. However, as of right now, not enough research has been done about the off target effects.
Sources: en.wikipedia.org
Laboratories commonly use liquid chromatography coupled with mass spectrometry to detect SR9009. The method can identify the compound and estimate concentration in a sample. Detection limits depend on the matrix and instrument.
Research-grade purity indicates a supplier's measured percentage of the intended compound. It does not guarantee safety, sterility, or suitability for human consumption. Buyers should request a certificate of analysis with chromatograms and test methods.
Sports regulators prohibit SR9009 because it is a non-approved substance with potential performance-altering effects. Its presence can be detected in anti-doping testing. Athletes are responsible for substances found in their samples.
It is a synthetic compound studied as an agonist of REV-ERB nuclear receptors. It is not an approved medicine and has mainly been examined in laboratory and animal research.