nuclear receptor comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-04-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| 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. |
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.
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.
Laboratory studies often administer SR9009 by injection because oral absorption appears poor in rodents. Reported pharmacokinetic properties include rapid metabolism and low systemic exposure after oral dosing. Human pharmacokinetic data are sparse, so absorption, distribution, metabolism, and excretion in people are not well defined. Some research explores related REV-ERB compounds with improved drug-like properties. Regulatory approval for any REV-ERB agonist as a human medicine has not been granted to date.
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.
Regulatory and sporting contexts treat SR9009 as a prohibited substance in many elite competitions. Its presence on banned lists reflects concerns about performance enhancement and unknown long-term safety. Analytical chemists have developed methods to detect the parent compound and its metabolites in urine and blood. Literature discussions distinguish between in vitro potency, animal pharmacology, and anecdotal human reports. The latter are difficult to verify because products sold online may lack purity or contain different compounds.
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, lipid metabolism, and inflammatory gene expression. In cell and animal experiments, SR9009 alters transcription of clock-controlled genes and metabolic pathways. The compound is not a hormone and does not resemble classical steroid structures. Its activity depends on binding to the ligand-binding domain of REV-ERB, where it can modify corepressor recruitment.
=== Urinary glucose testing === Women with GDM may have high glucose levels in their urine (glucosuria). Although dipstick testing is widely practiced, it performs poorly, and discontinuing routine dipstick testing has not been shown to cause underdiagnosis where universal screening is performed. Increased glomerular filtration rates during pregnancy contribute to some 50% of women having glucose in their urine on dipstick tests at some point during their pregnancy. Glomerular filtration rates increase during pregnancy due to an increase in blood volume to support the fetus. The sensitivity of glucosuria for GDM in the first two trimesters is only around 10%, and the positive predictive value is around 20%.
Like the genus Lactarius, russulas have a distinctive flesh consistency, which is also reflected in the appearance of the gills and stipe, and normally makes them immediately recognizable. They have no trace of a veil (no ring, or veil remnants on the cap). The gills are brittle except in a few cases, and cannot be bent parallel with the cap without breaking. Hence the genus Russula is sometimes known colloquially as "brittle gills". They have splitting gills and do not exude a milky substance at cut surfaces, contrary to the genus Lactarius. Presence of large spherical cells, 'sphaerocysts', in the stipe is an important characteristic feature to distinguish the members of Russulaceae from other mushrooms. In Russula, the stipe breaks like the flesh of an apple, while in most other families it only breaks into fibres. The spore powder varies from white to cream, or even orange. While it is relatively easy to identify a sample mushroom as belonging to this genus, it is a significant challenge to distinguish member species of Russula. This task often requires microscopic characteristics, and subtle subjective distinctions, such as the difference between a mild to bitter and a mild to acrid flavor. Moreover, the exact phylogenetic relationships of these mushrooms have yet to be resolved in the professional mycological community, and may ultimately depend on DNA sequencing analysis. The following characteristics are often important in identifying individual species:
=== Phenylbutyrate therapy === Sodium phenylacetate/benzoate or sodium phenylbutyrate has been shown to reduce BCAA in a clinical trial done February 2011. Phenylbutyrate treatment reduced the blood concentration of BCAA and their corresponding BCKA in certain groups of MSUD patients and may be a possible adjunctive treatment.
Sources: en.wikipedia.org
== Transmutation of technetium to stable ruthenium-100 == Technetium (Tc) can be completely transformed into ruthenium-100 by coating the inner cladding of fuel rods with Tc. This works with conventional pressurized water reactors and does not require specialized transmutation facilities. An alternative disposal method, transmutation, has been demonstrated at CERN and NIIAR for technetium-99. This transmutation process bombards the technetium (99Tc as a metal target) with neutrons, forming the short-lived 100Tc (half-life 16 seconds), which decays by beta decay to stable ruthenium (100Ru). Given the relatively high market value of ruthenium and the particularly undesirable properties of technetium, this type of nuclear transmutation appears particularly promising.
== Function == Glucagon-like peptide-1 (GLP-1) is a hormone consisting of 30 amino acids. GLP-1 is released by intestinal L cells when nutrients are consumed. GLP1R is expressed on beta cells in the pancreas. Binding of GLP-1 to GLP1R has multiple effects, including enhancing insulin secretion from pancreatic beta cells in response to glucose, increasing insulin expression, preventing beta-cell apoptosis, promoting the formation of new beta cells, reducing glucagon secretion, slowing down stomach emptying, promoting satiety, and improving glucose disposal in peripheral tissues. GLP1R is also expressed in the brain where it is involved in the control of appetite.
Raw feeding is the practice of feeding domestic dogs, cats and other animals a diet consisting primarily of uncooked meat, edible bones, and organs. The ingredients used to formulate raw diets can vary. Some pet owners choose to make homemade raw diets to feed their animals but commercial raw food diets are also available. Frozen, or fresh-prepared, meals come in raw or cooked form, some of which is made with ingredients that are inspected, approved, and certified by the USDA for human consumption, but formulated for pets. Part of this growing trend is the commercialization of home-made dog food for pet owners who want the same quality, but do not have the time or expertise to make it themselves. The advantage is forgoing the processing stage that traditional dog food undergoes. This causes less destruction of its nutritional integrity. The practice of feeding raw diets has raised some concerns due to the risk of foodborne illnesses, zoonosis and nutritional imbalances. People who feed their dogs raw food do so for a multitude of reasons, including but not limited to: culture, beliefs surrounding health, nutrition and what is perceived to be more natural for their pets. Feeding raw food can be perceived as allowing the pet to stay in touch with their wild, carnivorous ancestry. The raw food movement has occurred in parallel to the change in human food trends for more natural and organic products.
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 REV-ERB agonist used mainly in preclinical research. It is not an approved medicine for human use.