This is a working overview of NR1D1, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-03-15 and is reviewed periodically as new material appears.
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.
Laboratory samples of SR9009 are typically handled as research chemicals rather than pharmaceuticals. Suppliers usually state that the material is for research use only and not for human or veterinary administration. Storage recommendations generally call for a freezer at approximately −20 °C, protection from light, and a desiccated environment. The solid is often described as a white to off-white powder. Solubility is commonly reported in organic solvents such as dimethyl sulfoxide and ethanol, with low solubility in water.
Analytical identification and purity assessment often use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Liquid chromatography–tandem mass spectrometry is used to detect and quantify SR9009 in biological matrices, including urine and blood, for anti-doping or pharmacokinetic studies. Nuclear magnetic resonance spectroscopy can confirm molecular structure. Stability depends on form and storage: the solid is generally more stable than solutions, and repeated freeze–thaw cycles may degrade samples. Purity is typically reported as a percentage from a certificate of analysis.
Regulatory treatment of SR9009 varies by country and context. It is not approved as a therapeutic drug by agencies such as the United States Food and Drug Administration or the European Medicines Agency. Sports authorities list it as a prohibited substance; the World Anti-Doping Agency classifies it among hormone and metabolic modulators. Legal status for personal possession or sale differs across jurisdictions, and some countries may restrict it under analog or research chemical laws. Buyers who seek verified material often rely on independent laboratory testing because online product labels may not match contents.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Not approved for human use | Investigational status in most countries |
| Sports status | Prohibited by WADA | Classified as non-approved or metabolic modulator |
| Common analytical method | LC-MS/MS | Used for trace detection in biological samples |
| Typical test matrices | Urine and blood | Sample choice depends on testing program |
| Human trial data | None published | Effects and safety are not established |
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.
Preclinical reports describe effects on exercise endurance, mitochondrial content, and lipid profiles in rodents, but these findings come from specific experimental conditions. Many studies use high doses or delivery methods that may not translate directly to human use. SR9009 has been reported to have low oral bioavailability and a short half-life, which complicates interpretation of oral dosing studies. It is not established as safe or effective for any indication. Literature discussions often separate its pharmacological mechanism from unverified claims made in fitness and supplement markets.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ, also called NR1D1 and NR1D2. These receptors help regulate circadian rhythms and metabolic gene programs. The compound was developed for laboratory research, not as an approved therapeutic. Its identity is distinct from steroid hormones and selective androgen receptor modulators. Scientific interest centers on how REV-ERB activation changes gene expression in cells and animal models.
At the molecular level, SR9009 binds the ligand-binding domain of REV-ERB and strengthens recruitment of corepressor proteins such as NCoR and HDAC3. This increases repression of target genes, including Bmal1 and other clock-controlled and metabolic genes. In rodent studies, such changes have been linked to altered lipid handling, glucose metabolism, and energy expenditure. The precise chain of events between receptor binding and whole-body effects remains an active area of research. Findings in animals do not automatically translate to humans.
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.
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.
Robert William Barker (December 12, 1923 – August 26, 2023) was an American media personality, game show host, and animal rights advocate. He hosted CBS's The Price Is Right, the longest-running game show in North American television history, from 1972 to 2007. Barker also hosted Truth or Consequences from 1956 to 1975. Born in Darrington, Washington, in modest circumstances, Barker spent most of his youth on the Rosebud Indian Reservation and was a citizen of the Rosebud Sioux Tribe. Barker joined the United States Navy Reserve during World War II. He worked part-time in radio while attending college. In 1950, Barker moved to California to pursue a broadcasting career. He was given his own radio show, The Bob Barker Show, which ran for six years. Barker began his game show career in 1956, hosting Truth or Consequences. Barker began hosting The Price Is Right in 1972. He became an advocate for animal rights and of animal rights activism, supporting groups such as the United Activists for Animal Rights, People for the Ethical Treatment of Animals, and the Sea Shepherd Conservation Society. In 2007, Barker retired from hosting The Price Is Right after celebrating his 50-year career on television. Regarded as a pop culture icon, Barker continued to make occasional appearances for several years into his retirement until 2015.
== Mathematical analysis of the FcRn mechanism == Antibody binding, salvage and recycling by FcRn is an important part of modelling antibody pharmacokinetics. In fact, besides target-mediated drug dispostiion (TMDD), it is one of the most important factors mediating (non-specific) antibody elimination. Such a mechanism lies at the core of most physiology-based pharmacokinetic (PBPK) models of antibodies, see e.g. Garg and Balthasar, 2007; Shah and Betts, 2012; Niederal et al., 2018; Glassman and Balthasar, 2019; de Witte et al., 2023; De Sutter et al. (2024). Some of first steps towards understanding and gaining mathematical insight into the FcRn mechanism was taken by Patsatzis et al. (2022), using the computational singular perturbation (CSP) approach to analyse a minimal FcRn model. This preliminary work was extended and deepend by Katai et al. (2024) using the method of matched asymptotic expansions. This latter work constituted an asymptotic analysis of the mechanism in the high binding affinity limit, i.e. where binding was assumed to be an order of magnitude faster than all other processes. This resulted in a three-tiered scaling framework for non-saturating doses, with binding on the fastest time scale (typically over seconds or minutes), all other cellular process on an intermediate time scale (hours) and a long 'effective' elimination time scale (days, weeks).
Inactivated rabies virus (by injection) Modern injected vaccines are CCEEVs technologically similar to what is used in humans. They are packaged as single-dose vials; the contents of the vials may either be a lyophilized powder (like in human CCEEVs) or a ready-for-injection liquid. Imrab is an example containing the Pasteur strain of killed rabies virus. Several different types of Imrab exist, including Imrab, Imrab 3, and Imrab Large Animal. Imrab 3 has been approved for ferrets and, in some areas, pet skunks. Modified live viruses (by mouth) Live rabies virus from attenuated strains. Attenuated means strains that have developed mutations that cause them to be weaker and do not cause disease. Recombinant live viral vector vaccine (by mouth) In this kind of vaccine, a suitably weak non-rabies virus is genetically modified to produce the antigenic "shell" of the rabies virus such as the rabies glycoprotein. As a result, the virions it makes after entering a cell would also have the shell of the rabies virus, allowing the immune system to learn about the antigen. It does not cause rabies because it does not have any other gene from rabies, but it may still be transmissible among animals depending on the design (replication-competence). Only the first two types are approved for pets and are eligible for a vaccination certificate. The last is generally only available to government agencies for use on wildlife.
Sources: en.wikipedia.org
Reptilian skin is covered in a horny cornified epidermis, making it watertight and enabling reptiles to live on dry land, in contrast to amphibians. Compared to mammalian skin, that of reptiles is rather thin and lacks the thick dermal layer that produces leather in mammals. The scaly skin typical of reptiles was likely inherited from the mutual common ancestor of amniotes, as early synapsids (as well as close relatives of amniotes like diadectomorphs) also had scaly reptile-like skin. This epidermis has differentiated alpha- and beta-keratin layers. Reptile skin varies from being highly pliable (snakes, geckoes) to inflexible (crocodilians, many turtles, many lepidosaurs) and the scales from highly overlapping (skinks and snakes) to having very little overlap (crocodilians, geckoes and agamids). Some areas of the body may not covered in scales (such as large areas of the body in turtles), but still generally have a rough appearance. Large plate-like scales, such as those covering the shells of turtles and the bodies of crocodilians, are referred to as scutes. The tips of reptile digits are generally capped with hard, curved cornified claws.
In February 1941, Banting died of wounds and exposure following the crash of a Lockheed L-14 Super Electra/Hudson in which he was a passenger, in Musgrave Harbour, Newfoundland. After departing from Gander, Newfoundland, both of the plane's engines failed. The navigator and co-pilot died instantly, but Banting and the pilot, Captain Joseph Mackey, survived the initial impact. According to Mackey, the sole survivor, Banting died from his injuries the next day. Banting was en route to England to conduct operational tests on the Franks flying suit developed by his colleague Wilbur Franks. Banting and his wife are buried at Mount Pleasant Cemetery in Toronto.
After Geelong under Thompson were eliminated from the preliminary finals to Collingwood, at the conclusion of the 2010 season, on 4 October 2010, Thompson announced his retirement and resignation as Geelong Football Club senior coach effective immediately, his reason being that he was "tired of coaching" after a decade at the helm. Thompson was replaced by Chris Scott as Geelong Football club senior coach.
Sources: en.wikipedia.org
No. It is an investigational compound without approved therapeutic indications. It is sold for research purposes only in many jurisdictions.
Sports authorities prohibit it because it is not approved for human use and has potential performance-enhancing effects. It appears on anti-doping lists under non-approved or metabolic modulator categories.
Detection usually uses liquid chromatography-tandem mass spectrometry. The method targets the parent compound or its metabolites in urine or blood.
Legality depends on the country and the intended use. In many places it is sold as a research chemical, but sports and medicine regulations restrict it.