This is a working overview of NR1D2, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-11-18 and is reviewed periodically as new material appears.
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.
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 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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic REV-ERB agonist | Small molecule; not a steroid or peptide. |
| Primary targets | NR1D1 and NR1D2 | Also known as REV-ERBα and REV-ERBβ. |
| Studied routes | Intraperitoneal in rodents | Oral bioavailability in humans is not established. |
| Human approval | No approved therapeutic indication | No recognized clinical use. |
| Key uncertainty | Human physiological effects | Preclinical findings may not translate. |
Regulatory agencies have not approved SR9009 for human therapeutic use. It is typically sold as a research chemical with labels stating that it is not for human consumption. The World Anti-Doping Agency prohibits the substance in sport, generally under the category of non-approved substances. Customs and national laws may restrict importation, sale, or possession. Product quality and legal status can vary by country and vendor, and therapeutic claims are not permitted in regulated advertising because the compound lacks approval.
Several misconceptions surround SR9009. It is often described as a SARM, a steroid, or an exercise pill, but its known target is the REV-ERB receptor family. Rodent studies have examined exercise capacity and metabolic markers, yet human outcomes remain unproven. Oral bioavailability appears low in animals, and human pharmacokinetics are not well characterized. Online products may contain impurities or different compounds, so identity and purity testing are important for research use.
== Associated conditions == The increase in obesity prevalence has occurred alongside rising rates of diabetes and other metabolic disorders. According to Vigitel, the prevalence of self-reported medical diagnosis of diabetes increased from 5.5% in 2006 to 12.9% in 2024. The trend closely parallels the increase in obesity prevalence observed during the same period. Obesity is associated with a wide range of chronic diseases in Brazil, including type 2 diabetes, hypertension, dyslipidemia, obstructive sleep apnea, osteoarthritis, and several forms of cancer. The Brazilian Association for the Study of Obesity and Metabolic Syndrome and international clinical guidelines recognise obesity as a chronic, relapsing, multifactorial disease requiring long-term management. The Organisation for Economic Co-operation and Development has identified obesity as one of the most important modifiable risk factors affecting population health in Brazil.
== Exploration of L-Threonine for Tuberculosis == With multidrug-resistant Mycobacterium tuberculosis (TB) remaining a public health crisis with a total of 1.25 million people dead worldwide from TB in 2023 alone, new treatment strategies for TB are critical. TB is an airborne infection, spread via inhalation of airborne droplets that can remain suspended in the air for several hours, and can either be killed, remain in a latent stage, or become active. One previous paper researched the inhibitory effects of the downstream product L-threonine on the homoserine kinase (HSK) pathway in Escherichia coli. They found that the HSK pathway can be successfully inhibited via L-threonine since the pathway acts as a negative feedback loop, becoming inhibited once enough of the product is formed. Investigation of this pathway in TB may yield new insights into potential drug targets. Inhibiting the fatty acid synthesis pathway as well could serve as a potential drug target since this pathway is responsible for synthesizing mycolic acids, components necessary for formation of TB's cell walls. Coupling of the amino acid L-threonine with a common TB drug that inhibits fatty acid synthesis, like ethionamide, could yield a new treatment strategy for tuberculosis.
=== Vibrational circular dichroism of proteins === The more recent developments of vibrational circular dichroism (VCD) techniques for proteins, currently involving Fourier transform (FT) instruments, provide powerful means for determining protein conformations in solution even for very large protein molecules. Such VCD studies of proteins can be combined with X-ray diffraction data for protein crystals, FT-IR data for protein solutions in heavy water (D2O), or quantum computations.
Sources: en.wikipedia.org
A medical physicist is a health professional with specialist education and training in the concepts and techniques of applying physics in medicine and competent to practice independently in one or more of the subfields (specialties) of medical physics. A medical physicist plays a fundamental role in applying physics to medicine, but particularly in the diagnosis and treatment of cancer. The scientific and technological progress in medical physics has led to a variety of skills that must be integrated into the role of a medical physicist in order for them to perform their job. The "medical services" provided to patients undergoing diagnostic and therapeutic treatments must, therefore, be the result of different but complementary skills. In general, the medical physicist is responsible for all scientific and technical aspects of imaging, radiation treatment, and radiation safety. It is their occupational role to ensure that medical modalities offered to patients are met with the utmost quality assurance. It is the medical physicist that manages and supervises the efforts of dosimetrists, therapists and technologists in that capacity.
=== Screening of DELs in cells === DNA-encoded libraries (DELs) have been adapted for screening in living cells to better reflect native biological conditions, specifically using Xenopus laevis oocytes. This approach, termed cellular Binder Trap Enrichment (cBTE), facilitates the identification of small-molecule ligands that bind to target proteins in a native cellular environment. In this method, the protein of interest (POI) is expressed in oocytes as a fusion with a "Prey" protein, such as carbonic anhydrase IX (CAIX). Simultaneously, a "Bait" molecule—comprising a known ligand for the Prey protein linked to a DNA strand—is introduced. Alongside the Bait, a DEL is co-injected into the oocytes. If a DEL member binds to the POI, it brings its attached DNA tag into the same molecular complex as the Bait DNA via the POI–Prey–Bait interaction. Following incubation, the oocytes are lysed, and the lysate is subjected to Binder Trap Enrichment (BTE) as described above. In essence, the DEL and Bait DNA are ligated in droplets, thus encoding the binding event. The ligated DNA is then amplified and subjected to high-throughput sequencing to identify the DEL members that interacted with the POI.
=== Inner systematics === A 2011 study supported separating megabats and microbats. However, other and more recent evidence indicates that megabats belong within the microbats. Two new suborders have been proposed; Yinpterochiroptera includes the Pteropodidae, or megabat family, as well as the families Rhinolophidae, Hipposideridae, Craseonycteridae, Megadermatidae, and Rhinopomatidae. Yangochiroptera includes the other families of bats (all of which use laryngeal echolocation), a conclusion supported by a 2005 DNA study. A 2013 phylogenomic study supported the two new proposed suborders.
=== Neuropathic pain === Gabapentin is recommended as a first-line treatment for chronic neuropathic pain by various medical authorities. This is a general recommendation applicable to all neuropathic pain syndromes except for trigeminal neuralgia, where it may be used as a second- or third-line agent. Regarding the specific diagnoses, a systematic review has found evidence for gabapentin to provide pain relief for some people with postherpetic neuralgia and diabetic neuropathy. Gabapentin is approved for the former indication in the US. In addition to these two neuropathies, European Federation of Neurological Societies guideline notes gabapentin effectiveness for central pain. A combination of gabapentin with an opioid or nortriptyline may work better than either drug alone. Evidence finds little or no benefit and significant risk in those with chronic low back pain or sciatica. Gabapentin is not effective in HIV-associated sensory neuropathy and neuropathic pain due to cancer.
Sources: en.wikipedia.org
Anna, these actions were "an unparalleled act of violence and unprecedented human rights abuse." It is very certain that this popular unrest was one of the causes for the riots that surrounded the dismissal of Monteagudo on July 25, 1822, since it was perceived, in the feelings of the Lima population of all social classes, as a very unfair act because it is an abuse against Spaniards who had lived in Peru for decades and who had an important social and economic role. According to Scarlett O'Phelan, Monteagudo's measures were about to generate the annihilation of the social group of merchants who were active in very important areas for the Peruvian economy (these being agriculture and, above all, mining). This was due to the fact that the large, small, and medium-sized owners (all expropriated without much difference) were responsible for managing the most vital aspects of the viceroyalty's economy. It is also known that battalions of Argentine origin generated complaints from the civilian population due to the "havoc and exhortations" they carried out on the farms, devastating the crops and even attacking (sometimes seriously injuring) a large part of the members of the Peasant, who worked the land.
== Breeding == Potatoes, both S. tuberosum and most of its wild relatives, are self-incompatible: they bear no useful fruit when self-pollinated. This trait is problematic for crop breeding, as all sexually produced plants must be hybrids. The gene responsible for self-incompatibility, as well as mutations to disable it, are now known. Self-compatibility has successfully been introduced both to diploid potatoes (including a special line of S. tuberosum) by CRISPR-Cas9. Plants having a 'Sli' gene produce pollen which is compatible to its own parent and plants with similar S genes. This gene was cloned by Wageningen University and Solynta in 2021, which would allow for faster and more focused breeding. Diploid hybrid potato breeding is a recent area of potato genetics supported by the finding that simultaneous homozygosity and fixation of donor alleles is possible. Wild potato species useful for breeding blight resistance include Solanum desmissum and S. stoloniferum, among others.
Each February, Tim Hortons holds a marketing campaign titled "Roll Up the Rim to Win". As of 2007, over 31 million prizes were distributed each year, including cars, televisions, and store products. Customers determine if they have won prizes by unrolling the rim on their paper cups when they have finished their drink, revealing the result underneath. Prizes are not distributed randomly country-wide; each of the company's distribution regions has distinct prize-winning odds. The idea for the campaign began in 1985 when Roger Wilson of one of Tim Hortons' supplier of cups, Lily Cup company, approached Tim Hortons with a new idea to increase their sales. Wilson explained his company had created a new cup design that allowed a message to be printed under the rim; the cup type cost no more than the current one and could enable a promotion or contest. Recognizing the opportunity to promote coffee in the normally weak sales period in the spring, the Roll Up the Rim to Win campaign was first held in 1986 when the biggest prize was a snack box of Timbits. In 2008, over 88% of major prizes were redeemed. The contest is popular enough that Paul Kind invented the Rimroller (as seen on Dragons' Den), a device for rolling up the rim mechanically. The contest has seen several controversies including the theft of unrolled cups. In March 2006, two families were fighting over a Toyota RAV4 SUV prize of CA$32,000 value when their daughters found a winning "roll up the rim" coffee cup in a garbage bin of an elementary school in Saint-Jérôme, Quebec.
Sources: en.wikipedia.org
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.
REV-ERB receptors generally repress transcription when bound by natural heme. SR9009 is described as an agonist that enhances this repressive activity. The result is altered expression of clock and metabolic genes.
Published controlled human trials are lacking. Some sources cite limited or unofficial reports, but these do not establish safety or efficacy. Claims about human performance effects remain unverified.
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.