circadian clock raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-08-10 and is reviewed periodically as new material appears.
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.
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.
Preclinical reports have linked SR9009 to improved endurance and altered energy expenditure in rodents. Such findings have prompted interest in whether REV-ERB activation can influence skeletal muscle metabolism. However, the reported effects depend on dose, route, and experimental model, and replication across laboratories is limited. Human trials have not established comparable outcomes, so claims about exercise performance remain speculative. The absence of controlled human data is a central limitation in interpreting these observations.
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.
| 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 developed as a REV-ERB agonist. It binds to REV-ERBα and REV-ERBβ, nuclear receptors that help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, the compound alters lipid and glucose handling and influences skeletal muscle oxidative capacity. Its exact effects in humans remain largely uncharacterized because controlled clinical trials have not been reported. The molecule is frequently described in preclinical literature as a metabolic modulator.
Research interest in SR9009 grew from studies showing improved running endurance in mice after short treatment periods. Those experiments linked the compound to increased mitochondrial content and fatty acid oxidation in muscle, but the findings come from animal models and specific dosing schedules. Independent replication has been limited, and the pathways connecting REV-ERB activation to exercise performance are still being mapped. Whether similar responses occur in humans is an open question.
SR9009 is often grouped with compounds studied for circadian and metabolic regulation rather than with classical anabolic steroids. Its interactions with nuclear receptors differ from those of androgen receptor ligands, and its proposed mechanisms involve transcriptional control rather than direct hormone signaling. Some sources classify it as a metabolic modulator because of observed effects on energy utilization. The distinction matters for regulation and for interpreting research results across different compound classes.
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.
== External links == "einsteinium (Es) - chemical element". Britannica.com. Retrieved 23 May 2017. "mendelevium (Md) - chemical element". Britannica.com. Retrieved 23 May 2017. "synthetic elements". Encyclopedia2.thefreedictionary.com. Retrieved 23 May 2017. "It's Elemental - The Element Fermium". Education.jlab.org. Retrieved 23 May 2017. Kulkarni, Mayuri (15 June 2009). "A Complete List of Man-made Synthetic Elements". ScienceStuck. Retrieved 15 May 2019.
3-Methylfentanyl (3-MF, mefentanyl) is an opioid analgesic that is an analog of fentanyl. 3-Methylfentanyl is one of the most potent opioids, estimated to be between 400 and 6000 times stronger than morphine, depending on which isomer is used (with the cis isomers being the more potent ones).
The area returned to the English crown in 1157, when Henry II of England took possession of the area (from Malcolm IV of Scotland). Henry II formed two new counties from the former earldom: Westmorland and Carliol – originally an abbreviation of the Latin Carlioliensis '[bishop] of Carlisle'. Westmorland also included areas formerly part of the Earldom of Lancaster. The lead- and silver-mining area of Alston, previously associated with the Liberty of Tynedale was later also added to the new county of Carliol for financial reasons. By 1177, Carliol had become known as Cumberland. The border between England and Scotland was made permanent by the Treaty of York in 1237. The population of Cumberland in the 1841 census was 178,038.
== Terminology == "Redox" is a portmanteau of "reduction" and "oxidation". The term first appeared in a 1928 article by Leonor Michaelis and Louis B. Flexner. Oxidation is a process in which a substance loses electrons. Reduction is a process in which a substance gains electrons. The processes of oxidation and reduction occur simultaneously and cannot occur independently. In redox processes, the reductant transfers electrons to the oxidant. Thus, in the reaction, the reductant or reducer or reducing agent loses electrons and is oxidized, while the oxidant or oxidizer or oxidizing agent gains electrons and is reduced. The pair of an oxidizing and reducing agent that is involved in a particular reaction is called a redox pair. A redox couple is a reducing species and its corresponding oxidizing form, e.g., Fe2+/ Fe3+.The oxidation alone and the reduction alone are each called a half-reaction because two half-reactions always occur together to form a whole reaction. In electrochemical reactions the oxidation and reduction processes do occur simultaneously but are separated in space. Although oxidation is commonly associated with forming oxides, other chemical species can serve the same function; in hydrogenation, bonds such as C=C are reduced by the transfer of hydrogen atoms.
Sources: en.wikipedia.org
=== Administrative work === In 1959, after offering advice to Yale president A. Whitney Griswold on strengthening the sciences at Yale, Fruton became director of the division of science, a position he held until 1962. His work led to the creation of the short-lived department of molecular biology and biophysics (MBB), although his initial proposal to create a similar department that combined the existing biophysics and biochemistry departments was rejected. Fruton became burnt out on Yale politics after an extended conflict with provost Kingman Brewster, in which Brewster attempted to bypass Fruton's science advisory committee and create a molecular biology department independent of biochemistry department; the MBB department was created only after Brewster had failed to attract a prominent scientist from outside Yale to head a molecular biology department, and the department of biochemistry remained separate as part of the medical school until the creation of the department of molecular biophysics & biochemistry (MB&B) in 1969 (which was itself created after a lengthy and unsuccessful attempt to find a suitably eminent replacement for Fruton to head the department of biochemistry). Fruton was elected to the American Philosophical Society in 1968.
== History == In traditional oil painting as practiced by the Renaissance painter, skin glue was used to seal the canvas. This is necessary because the linseed oil that forms the base of most oil paint contains linolenic acid that will destroy the canvas fibers over time. Renaissance artists also knew that pure size (hide glue) became brittle once dry, and would mix it with oil and chalk to make a "half-ground" for canvases. Pure hide glue was usually applied only to rigid supports like panels. Though this does help to seal the canvas or panel, artists still applied a layer of "oil ground", which was often lead-based paint, in order to provide a binding layer for the final oil paint to adhere to.
== Development == Prior to enamel formation, dentin formation begins through a process known as dentinogenesis, and this process continues throughout a person's life even after the tooth has fully developed. Events such as tooth decay and tooth wear can also initiate dentin formation. Dentinogenesis is initiated by the odontoblasts of the pulp. Odontoblasts are specialised cells that lay down an organic matrix known as pre-dentin. This predentin is subsequently mineralized into dentin. Mineralization of predentin begins at the dentinoenamel junction during tooth development and progresses towards the pulp of the tooth. After growth of predentin and maturation into dentin, the cell bodies of the odontoblasts remain in the pulp, along its outer wall, and project into tiny tubules in the dentin. Predentin is composed of 90% type I collagen and 10% non-collagenous proteins (including phosphoproteins, proteoglycans, growth factors, phosphatases such as alkaline phosphatase, and matrix metalloproteinases (MMPs)), and this composition is significantly altered when it is mineralized into dentin. See the Structure section for information about the composition of dentin.
Sources: en.wikipedia.org
Methocarbamol, sold under the brand name Robaxin among others, is a medication used for short-term musculoskeletal pain. It may be used together with rest, physical therapy, and pain medication. It has limited use for rheumatoid arthritis and cerebral palsy. Effects generally begin within half an hour. It is taken by mouth or injection into a vein. Common side effects include headaches, sleepiness, and dizziness. Serious side effects may include anaphylaxis, liver problems, confusion, and seizures. Use is not recommended in pregnancy and breastfeeding. Because of the risk of injury, skeletal muscle relaxants should generally be avoided in geriatric patients. Methocarbamol is a centrally acting muscle relaxant. How it works is unclear, but it does not appear to affect muscles directly. Methocarbamol was developed in 1956 in the laboratories of A. H. Robins (later acquired by Pfizer). Studies were directed towards the development of propanediol derivatives which possessed muscle relaxant properties superior to those of mephenesin, which had low potency and a short duration of action. It was approved for medical use in the United States in 1957. It is available as a generic medication. In 2023, it was the 121st most commonly prescribed medication in the United States, with more than 5 million prescriptions. Methocarbamol is available in a fixed-dose combination with ibuprofen as methocarbamol/ibuprofen (sold under the brand name Summit Ultra).
The related drug metformin is considerably safer than phenformin, with three cases of lactic acidosis per 100,000 patient-years compared to 64 cases per 100,000 patient-years, and those are mostly confined to patients with impaired renal function.
=== Hostage-taking === According to the Human Rights Watch, the Houthis also use hostage taking as a tactic to generate profit. Human Rights Watch documented 16 cases in which Houthi authorities held people unlawfully, in large part to extort money from relatives or to exchange them for people held by opposing forces.
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 a synthetic compound that acts as an agonist at REV-ERBα and REV-ERBβ. It is used mainly as a research chemical to study circadian and metabolic pathways. It is not approved for human therapeutic use.