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 2026-07-06 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Common name | SR9009 | Also referred to as Stenabolic in non-scientific contexts. |
| Chemical class | Synthetic small molecule | Not a steroid or peptide hormone. |
| Receptor target | REV-ERBα and REV-ERBβ | Nuclear receptor agonist in preclinical studies. |
| Development status | Investigational | No approved human therapeutic indication. |
| Regulatory attention | Prohibited in sport | Listed by anti-doping authorities. |
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 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.
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.
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.
== Mechanism in the trp operon == The proposed mechanism of how this mRNA secondary structure and the trp leader peptide could regulate transcription of the trp biosynthetic enzymes includes the following.
Time-of-flight mass spectrometry (TOFMS) is a method of mass spectrometry in which an ion's mass-to-charge ratio is determined by a time of flight measurement. Ions are accelerated by an electric field of known strength. This acceleration results in an ion having the same kinetic energy as any other ion that has the same charge. The velocity of the ion depends on the mass-to-charge ratio (heavier ions of the same charge reach lower speeds, although ions with higher charge will also increase in velocity). The time that it subsequently takes for the ion to reach a detector at a known distance is measured. This time will depend on the velocity of the ion, and therefore is a measure of its mass-to-charge ratio. From this ratio and known experimental parameters, one can identify the ion.
During the early 1800s, consumers preserved their food by storing food and ice purchased from ice harvesters in iceboxes. In 1803, Thomas Moore patented a metal-lined butter-storage tub which became the prototype for most iceboxes. These iceboxes were used until nearly 1910 and the technology did not progress. In fact, consumers that used the icebox in 1910 faced the same challenge of a moldy and stinky icebox that consumers had in the early 1800s. General Electric (GE) was one of the first companies to overcome these challenges. In 1911, GE released a household refrigeration unit that was powered by gas. The use of gas eliminated the need for an electric compressor motor and decreased the size of the refrigerator. However, electric companies that were customers of GE did not benefit from a gas-powered unit. Thus, GE invested in developing an electric model. In 1927, GE released the Monitor Top, the first refrigerator to run on electricity. In 1930, Frigidaire, one of GE's main competitors, synthesized Freon. With the invention of synthetic refrigerants based mostly on a chlorofluorocarbon (CFC) chemical, safer refrigerators were possible for home and consumer use. Freon led to the development of smaller, lighter, and cheaper refrigerators. The average price of a refrigerator dropped from $275 to $154 with the synthesis of Freon. This lower price allowed ownership of refrigerators in American households to exceed 50% by 1940.
Addiction is a serious risk with heavy recreational amphetamine use, but is unlikely to occur from long-term medical use at therapeutic doses; in fact, lifetime stimulant therapy for ADHD that begins during childhood reduces the risk of developing substance use disorders as an adult. Pathological overactivation of the mesolimbic pathway, a dopamine pathway that connects the ventral tegmental area to the nucleus accumbens, plays a central role in amphetamine addiction. Individuals who frequently self-administer high doses of amphetamine have a high risk of developing an amphetamine addiction, since chronic use at high doses gradually increases the level of accumbal ΔFosB, a "molecular switch" and "master control protein" for addiction. Once nucleus accumbens ΔFosB is sufficiently overexpressed, it begins to increase the severity of addictive behavior (i.e., compulsive drug-seeking) with further increases in its expression. While there are currently no effective drugs for treating amphetamine addiction, regularly engaging in sustained aerobic exercise appears to reduce the risk of developing such an addiction. Exercise therapy improves clinical treatment outcomes and may be used as an adjunct therapy with behavioral therapies for addiction.
=== Food === Many cultures have turned to foods as sources of increasing sexual desire; however, significant research is lacking in the study of the aphrodisiac qualities of foods. Most claims can be linked to the placebo effect. Misconceptions revolve around the visual appearance of these foods in relation to male and female genitalia (carrots, bananas, oysters, and the like). Other beliefs arise from the thought of consuming animal genitalia and absorbing their properties (e.g. cow cod soup in Jamaica and balut in the Philippines). Korean bug is a popular aphrodisiac in China, Korea, and Southeast Asia, either eaten alive or in gelatin form. The caterpillar fungus (Ophiocordyceps sinensis) is used as an aphrodisiac in China. The story of Aphrodite, who was born from the sea, is another reason why individuals believe seafood is another source of aphrodisiacs. Foods that contain volatile oils have gained little recognition in their ability to improve sexual desire, sexual pleasure, and/or sexual behavior, because they are irritants when released through the urinary tract. Chocolate has been reported to increase sexual desire in women who consume it over those who do not. Cloves and sage have been reported to demonstrate aphrodisiac qualities, but their effects have not been specified. Tropical fruits, such as Borojó and Chontaduro, are considered to be energizers in general and sexual energizers in particular.
Sources: en.wikipedia.org
Users can access the DHIS2 through any modern web browser. In addition, the DHIS2 Capture Android application can be used to collect and update DHIS2 data on mobile devices and tablets that use the Android operating system. When data is entered through the web or Android application, it is synced with the central DHIS2 server for that instance. Each individual instance of the DHIS2 software and the data it contains is locally owned and managed. DHIS2 includes support for translation and localization, and has already been translated into a number of languages including French, Portuguese, Spanish, Hindi, Vietnamese, Chinese and Norwegian. DHIS2 software development occurs in 12-month cycles of backend releases, plus periodic patch releases and continuous app releases. Development is coordinated by the HISP Centre according to a collaboratively planned, public roadmap that prioritizes generic improvements that meet country needs.
== Toxicity == One review on graphene toxicity published in 2016 by Lalwani et al. summarizes the in vitro, in vivo, antimicrobial and environmental effects and highlights the various mechanisms of graphene toxicity. Another review published in 2016 by Ou et al. focused on graphene-family nanomaterials (GFNs) and revealed several typical mechanisms such as physical destruction, oxidative stress, DNA damage, inflammatory response, apoptosis, autophagy, and necrosis. A 2020 study showed that the toxicity of graphene is dependent on several factors such as shape, size, purity, post-production processing steps, oxidative state, functional groups, dispersion state, synthesis methods, route and dose of administration, and exposure times. In 2014, research at Stony Brook University showed that graphene nanoribbons, graphene nanoplatelets, and graphene nano–onions are non-toxic at concentrations up to 50 μg/ml. These nanoparticles do not alter the differentiation of human bone marrow stem cells towards osteoblasts (bone) or adipocytes (fat), suggesting that at low doses, graphene nanoparticles are safe for biomedical applications. In 2013, research at Brown University found that 10 μm few-layered graphene flakes can pierce cell membranes in solution. They were observed to enter initially via sharp and jagged points, allowing graphene to be internalized in the cell. The physiological effects of this remain unknown, and this remains a relatively unexplored field.
Methods of semen collection include masturbation, condom collection, and epididymal extraction. The sample should never be obtained through coitus interruptus as some portion of the ejaculate could be lost, bacterial contamination could occur, or the acidic vaginal pH could be detrimental for sperm motility. The optimal sexual abstinence for semen sampling is two to seven days. The most common way to obtain a semen sample is through masturbation or withdrawal method and the best place to obtain it is in the clinic where the analysis will take place in order to avoid temperature changes during the transport that can be lethal for some spermatozoa. Once the sample is obtained, it must be put directly into a sterile plastic receptacle (never in a conventional condom, since they have chemical substances such as lubricants or spermicides that could damage the sample) and be handed to the clinic for it to be studied within the hour. There are some situations that necessitate alternative collection methods, such as retrograde ejaculation, neurological injury or psychological inhibition. Depending on the situation, specialized condoms, electrostimulation or vibrostimulation might be used.
== Education and career == Kessler studied chemistry at the Leipzig University in 1958–1961. He completed his Master (Diplom) in 1963, and his PhD at 1966 with Eugen Müller at the University of Tübingen. In 1969, he underwent habilitation in organic chemistry. He was briefly a university lecturer at Tübingen, then he obtained an organic chemistry lecturer position at the University of Frankfurt am Main. In 1989, he became Professor of organic chemistry and biochemistry at the Technical University of Munich (TUM), where he was in charge of overseeing the installation of one of the four 900 MHz NMR spectrometers in Germany at that time. At TUM, he was Dean of the Faculty of Chemistry, Biology and Earth Sciences from 1994 to 1996. From October 2008, he is a Carl-von-Linde Professor (Emeritus Professor of Excellence) at the TUM Institute for Advanced Study.
Other culinary gelling agents can be used instead of animal-derived gelatine. These plant-derived substances are more similar to pectin and other gelling plant carbohydrates than to gelatine proteins; their physical properties are slightly different, creating different constraints for the preparation and storage conditions. These other gelling agents may also be preferred for certain traditional cuisines or dietary restrictions. Agar, a product made from red algae, is the traditional gelling agent in many Asian desserts. Agar is a popular gelatine substitute in quick jelly powder mix and prepared dessert gels that can be stored at room temperature. Compared to gelatine, agar preparations require a higher dissolving temperature, but the resulting gels congeal more quickly and remain solid at higher temperatures, 40 °C (104 °F), as opposed to 15 °C (59 °F) for gelatine. Vegans and vegetarians can use agar to replace animal-derived gelatine. Another common seaweed-based gelatine substitute is carrageenan, which has been used as a food additive since ancient times. It was first industrially-produced in the Philippines, which pioneered the cultivation of tropical red seaweed species (primarily Eucheuma and Kappaphycus spp.) from where carrageenan is extracted. The Philippines produces 80% of the world's carrageenan supply. Carrageenan gelatine substitute are traditionally known as gulaman in the Philippines. It is widely used in various traditional desserts and are sold as dried bars or in powder form.
Sources: en.wikipedia.org
Vaginal secretions are primarily from the uterus, cervix, and vaginal epithelium in addition to minuscule vaginal lubrication from the Bartholin's glands upon sexual arousal. It takes little vaginal secretion to make the vagina moist; secretions may increase during sexual arousal, the middle of or a little prior to menstruation, or during pregnancy. Menstruation (also known as a "period" or "monthly") is the regular discharge of blood and mucosal tissue (known as menses) from the inner lining of the uterus through the vagina. The vaginal mucous membrane varies in thickness and composition during the menstrual cycle, which is the regular, natural change that occurs in the female reproductive system (specifically the uterus and ovaries) that makes pregnancy possible. Different hygiene products such as tampons, menstrual cups, and sanitary napkins are available to absorb or capture menstrual blood. The Bartholin's glands, located near the vaginal opening, were originally considered the primary source for vaginal lubrication, but further examination showed that they provide only a few drops of mucus. Vaginal lubrication is mostly provided by plasma seepage known as transudate from the vaginal walls. This initially forms as sweat-like droplets, and is caused by increased fluid pressure in the tissue of the vagina (vasocongestion), resulting in the release of plasma as transudate from the capillaries through the vaginal epithelium.
== Adverse effects == The adverse effects of pethidine administration are primarily those of the opioids as a class: nausea, vomiting, dizziness, diaphoresis, urinary retention, and constipation. Due to moderate stimulant effects mediated by pethidine's dopamine and norepinephrine reuptake inhibition, sedation is less likely compared to other opioids. Unlike other opioids, it does not cause miosis because of its anticholinergic properties. Overdose can cause muscle flaccidity, respiratory depression, obtundation, psychosis, cold and clammy skin, hypotension, and coma. A narcotic antagonist such as naloxone is indicated to reverse respiratory depression and other effects of pethidine. Serotonin syndrome has occurred in patients receiving concurrent antidepressant therapy with selective serotonin reuptake inhibitors (SSRIs) or monoamine oxidase inhibitors, or other medication types (see Interactions below). Convulsive seizures sometimes observed in patients receiving parenteral pethidine on a chronic basis have been attributed to accumulation in plasma of the metabolite norpethidine (normeperidine). Fatalities have occurred following either oral or intravenous pethidine overdose.
It also suppresses the norepinephrine-induced increase in the sarcoplasmic reticulum (SR) Ca2+ leak and the spontaneous SR Ca2+ release, which are the major triggers for atrial fibrillation. Through this mechanism of selective blockade at β1 receptors, metoprolol exerts the following effects:
9 January – Séamus Begley, 73, traditional musician and singer. 16 January Carrie Acheson, 88, politician, TD (1981–1982). Joe Martin, 91, footballer (Dundalk, League of Ireland XI). 18 January – John L. Murray, 79, jurist, chief justice (2004–2011), judge of the Supreme Court (1999–2015) and the ECJ (1992–1999). 19 January Bertie Cunningham, 83, Gaelic footballer (Ballivor, Meath senior team). Peter Thomas, 78, footballer (Waterford, Galway United, national team). Born in England. 20 January – Pierce Higgins, 45, hurler (Tooreen, Ballyhaunis, Mayo senior team), motor neuron disease. 21 January – Micheál Mac Gréil, 91, Jesuit priest, sociologist and writer. 30 January – Eddie Spence, 97, Gaelic footballer (Belfast O'Connell's, Antrim senior team). Born in Northern Ireland. 31 January – Donie Hanlon, 85, Gaelic footballer (Gracefield, Offaly senior team).
=== Method Development === Method development of chiral chromatography is still done by screening of columns from the various classes of chiral columns. While chiral separation mechanisms are understandable in certain scenarios, and the retention characteristics of analytes within the chromatographic columns can occasionally be elucidated, the precise combination of chiral stationary phases (CSPs) and mobile-phase compositions that required to effectively resolve a specific enantiomeric pair often remains elusive. The chemistry of CSP ligands significantly influences the creation of in-situ diastereomeric complexes upon the stationary phase surface. However, other method's conditions, such as mobile-phase solvents, their composition, mobile phase additives and column temperature can play equally critical roles. The final resolution of the enantiomers is the outcome of combination of intermolecular forces, and even a subtle change in them can determine the success or failure of separation. This complexity prevents from establishing routine method-development protocols that are universally applicable to a diverse range of enantiomers. In fact, sometimes the outcome of previous unsuccessful experiments do not provide any clue for the subsequent steps.
Sources: en.wikipedia.org
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.
No. It is a small molecule that binds nuclear receptors involved in circadian regulation. Its classification differs from anabolic steroids or peptide hormones.
Published human clinical trial data are lacking. Most safety and activity information comes from preclinical models, so effects in people remain uncertain.
It is a synthetic research compound that activates REV-ERB nuclear receptors. It is not an approved drug or dietary supplement. Most information comes from cell and animal studies.