bioavailability 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 2025-08-29 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.
Regulatory treatment of SR9009 reflects its investigational status. The compound has no approved human therapeutic indication, and sports authorities prohibit its use. It appears on anti-doping lists as a non-approved substance or metabolic modulator, depending on the list version. Products sold online as research chemicals are not quality-controlled medicines, so their identity and purity can differ from the label. Such products may also contain unlisted compounds, which complicates both testing and safety assessment.
Scientific discussion of SR9009 often separates animal evidence from human anecdote. Rodent studies provide controlled data on endurance, metabolism, and gene expression, but they use specific strains, doses, and treatment durations. Human reports are mostly uncontrolled and cannot establish cause and effect. Open questions include oral bioavailability, tissue distribution, metabolic stability, and long-term effects. Review articles generally call for more rigorous pharmacokinetic and safety research before any clinical use could be considered.
Analytical methods for SR9009 typically rely on liquid chromatography coupled with tandem mass spectrometry. The technique can separate the parent compound from related substances and detect low concentrations in biological matrices. Urine and blood are common samples in anti-doping testing, while in vitro studies may use cell culture media. Rapid metabolism and low expected concentrations make method validation important for reliable identification. Exact metabolite patterns can vary by species and are not fully mapped.
| 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 |
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 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.
Stability depends on physical form, temperature, light exposure, and solvent. Solid SR9009 is generally stored cold and dry, with protection from light to limit degradation. Dimethyl sulfoxide stocks are common for laboratory work, but repeated freeze-thaw cycles can reduce compound integrity. Aqueous solutions may be less stable than organic stocks, and the ethyl ester in the structure can be susceptible to hydrolysis under certain conditions. Researchers typically validate storage conditions and recheck purity before quantitative experiments, especially when using archived material.
Regulatory treatment of SR9009 varies by country and region. It is not approved as a pharmaceutical, and several jurisdictions restrict its sale for human consumption. Some authorities classify it as a research chemical, a prescription-only substance, or a prohibited performance-enhancing agent in sport. Purchasers may encounter certificates of analysis, but these documents do not guarantee identity, purity, or legality. In research settings, institutional safety reviews and controlled procurement help ensure that materials are handled under appropriate oversight. The absence of harmonized rules means that legal status can change and requires verification.
=== Starships and warp drives === Starships are living spaces, vehicles and ambassadors of the Culture. A proper Culture starship (as defined by hyperspace capability and the presence of a Mind to inhabit it) may range from several hundreds of metres to hundreds of kilometres. The latter may be inhabited by billions of beings and are artificial worlds in their own right, including whole ecosystems, and are considered to be self-contained representations of all aspects of Culture life and capability. The Culture (and most other space-faring species in its universe) use a form of Hyperspace-drive to achieve faster-than-light speeds. Banks has evolved a (self-confessedly) technobabble system of theoretical physics to describe the ships' acceleration and travel, using such concepts as "infraspace" and "ultraspace" and an "energy grid" between universes (from which the warp engines "push off" to achieve momentum). An "induced singularity" is used to access infra or ultra space from real space; once there, "engine fields" reach down to the Grid and gain power and traction from it as they travel at high speeds. These hyperspace engines do not use reaction mass and hence do not need to be mounted on the surface of the ship. They are described as very dense exotic matter, which only reveals its complexity under a powerful microscope. Acceleration and maximum speed depend on the ratio of the mass of the ship to its engine mass. As with any other matter aboard, ships can gradually manufacture extra engine volume or break it down as needed.
== Management == Biomedical waste must be properly managed and disposed of to protect the environment, general public and workers, especially healthcare and sanitation workers who are at risk of exposure to biomedical waste as an occupational hazard. Steps in the management of biomedical waste include generation, accumulation, handling, storage, treatment, transport and disposal. The development and implementation of a national waste management policy can improve biomedical waste management in health facilities in a country.
This layer acts as a nucleation site during the next step, where a process of electroless deposition layers a coating of gold on the nanotubes to form metal-insulator-metal trilayer coaxial nanocables. Peptide nanotubes are able to produce nanowires of uniform size, and this is particularly useful in the nano-electric applications as electrical and magnetic properties are sensitive to size. Nanotubes' exceptional mechanical strength and stability makes them excellent materials for application in this area. Nanotubes have also been used in developing electrochemical biosensing platforms and have proved to have great potential. Dipeptide nanotubes deposited on graphite electrodes improved electrode sensitivity; thiol-modified nanotubes deposited on gold with a coating of enzymes improved sensitivity and reproducibility for the detection of glucose and ethanol, as well as a shortened detection time, large current density, and improved stability. Nanotubes have also been successfully coated with proteins, nanocrystals, and metalloporphyrin through hydrogen bonding, and these coated tubes have great potential as chemical sensors. Designed peptides with a known structure that would self-assemble into a regular growth template would enable the self-assembly of nanoscale electronic circuits and devices. However, one issue that has yet to be resolved is the ability to control the positioning of the nanostructures. This positioning relative to substrates, to each other, and to other functional components is crucial.
== Use during the 20th century == During the 20th century its use declined as governments regulated its ingredients (opium is a controlled substance in many countries). Beginning in late 2011, there was a period in which paregoric was not being manufactured in the United States. As of August 2012, however, the manufacture of paregoric had resumed.
Sources: en.wikipedia.org
The Singaporean military, one of the smallest but most technologically advanced in Southeast Asia, consists of the Army, the Navy, the Air Force and the Digital and Intelligence Service. It is seen as the guarantor of the country's independence, translating into Singapore culture, involving all citizens in the country's defence. The government spent 2.7% of the country's GDP on the military in 2024, the highest in the region. After its independence, Singapore had only two infantry regiments commanded by British officers. Considered too small to provide effective security for the new country, the development of its military forces became a priority. In addition, in October 1971, Britain pulled its military out of Singapore, leaving behind only a small British, Australian and New Zealand force as a token military presence. A great deal of initial support came from Israel, a country unrecognised by Singapore's neighbouring Muslim-majority nations of Malaysia and Indonesia. The Israel Defense Forces (IDF) commanders were tasked by the Singapore Government to create the Singapore Armed Forces (SAF) from scratch, and Israeli instructors were brought in to train Singaporean soldiers. Military courses were conducted according to the IDF's format, and Singapore adopted a system of conscription and reserve service based on the Israeli model. Singapore still maintains strong security ties with Israel and is one of the biggest buyers of Israeli arms and weapons systems, with one recent example being the MATADOR anti-tank weapon.
== Pathophysiology == Solar purpura is believed to be caused by skin damage due to chronic sun exposure, which leads to dermal atrophy. As a result of the dermal atrophy, the dermal connective tissue cannot support the microvasculature, and the result is extravasation of blood into the dermis. This results in visible purple spots on the skin.
=== Synthesis === Early and seemingly inefficient syntheses of synephrine were discussed by Priestley and Moness, writing in 1940. These chemists optimized a route beginning with the O-benzoylation of p-hydroxy-phenacyl chloride, followed by reaction of the resulting O-protected chloride with N-methyl-benzylamine to give an amino-ketone. This intermediate was then hydrolyzed with HCl/alcohol to the p-hydroxy-aminoketone, and the product then reduced catalytically to give (racemic) synephrine. A later synthesis, due to Bergmann and Sulzbacher, began with the O-benzylation of p-hydroxy-benzaldehyde, followed by a Reformatskii reaction of the protected aldehyde with ethyl bromoacetate/Zn to give the expected β-hydroxy ester. This intermediate was converted to the corresponding acylhydrazide with hydrazine, then the acylhydrazide reacted with HNO2, ultimately yielding the p-benzyloxy-phenyloxazolidone. This was N-methylated using dimethyl sulfate, then hydrolyzed and O-debenzylated by heating with HCl, to give racemic synephrine.
Protein digestibility-corrected amino acid score (PDCAAS) is a method of evaluating the quality of a protein based on both the amino acid requirements of humans and their ability to digest it. The PDCAAS rating was recommended by the Food and Agriculture Organization of the United Nations/World Health Organization (FAO/WHO) in 1989 (report published in 1991). It was adopted by the US FDA in 1993 as "the preferred 'best'" method to determine protein quality. In 2013, FAO proposed changing to Digestible Indispensable Amino Acid Score.
It is a flat tax up to the cap, but regressive overall as it is not applied to higher incomes. The Medicare portion is also paid by employer and employee each at 1.45% and is not capped. Starting in 2013, an additional 0.9 percent more in Medicare taxes was applied to income of more than $200,000 ($250,000 for married couples filing jointly), making it a progressive tax overall. For calendar years 2011 and 2012, the employee's portion of the payroll tax was reduced to 4.2% as an economic stimulus measure; this expired for 2013. Approximately 65% percent of tax return filers pay more in payroll taxes than income taxes.
Sources: en.wikipedia.org
=== Cost effectiveness === The costs of methenamine for long-term UTI prophylaxis can be significant. However, a 2024 study found that methenamine was more cost-effective than low-dose prophylactic antibiotics for prevention of UTIs.
== War crimes == During the Battle of France, soldiers of the division perpetrated summary executions of hundreds of Black prisoners of war in French service. These executions were racially motivated, as German troops had been conditioned by Nazi propaganda to see Black people as subhuman. In several instances, Black prisoners of war were separated from White ones and murdered by soldiers of the division, including on 10 June 1940, where 150 Black prisoners were massacred in Erquinvillers. Another mass killing committed by the division was the Chasselay massacre; on 19-20 June hundreds of Black prisoners of war were murdered in Chasselay, Rhône.
== Awards == Hackenberger has received numerous awards for his work, including the Heinz Maier-Leibnitz Prize of the German Research Foundation (2011), the ORCHEM Prize of the German Chemical Society (2012), the Zervas Award of the European Peptide Society (2018), the Breakthrough of the Year Award in the life sciences from the Falling Walls Foundation (2020), the Astra-Zeneca Award of the Royal Society of Chemistry (2023), the Xiaoyu Hu Memorial Award of the Chinese Peptide Society (2023), and the Max Bergmann Medal (2024).
== Hormone and metabolic modulators == Hormone levels of a particular hormone, like testosterone, can be changed not only by administering it, but also by altering related hormones. For example, the estrogens estrone and estradiol are biosynthetically produced by the enzyme aromatase, respectively, from androstenedione and testosterone, which are both produced from 17α-hydroxyprogesterone. Thus, when the body senses low levels of estrogen, the precursor compounds 17α-hydroxyprogesterone, androstenedione, and testosterone are up-regulated. Likewise, interfering with a hormone's receptor leads to similar effects. Because of these natural hormone-hormone interdependent biosynthetic pathways and hormone-receptor interactions, all aromatase inhibitors, including anastrozole, letrozole, aminoglutethimide, exemestane, formestane, and testolactone are banned. Selective estrogen receptor modulators, including raloxifene, tamoxifen and toremifene are banned. Clomiphene, cyclofenil, fulvestrant, and all other anti-estrogenic substances are banned. Myostatin inhibitors are banned. Metabolic modulators including peroxisome proliferator-activated receptor delta (PPARδ) agonists (e.g., GW 1516), PPARδ-AMP-activated protein kinase (AMPK) axis agonists (e.g. AICAR) are also banned. Meldonium was banned on 1 January 2016, which was often used during the Russian doping scandal.
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.
No. It is an investigational compound without approved therapeutic indications. It is sold for research purposes only in many jurisdictions.