If you have been reading about nuclear receptor and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-05-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Common supplier description |
| Solubility | Soluble in DMSO and ethanol | Low solubility in water |
| Typical storage | −20 °C, desiccated, dark | For research samples |
| Analytical method | LC-MS/MS | Used for detection and quantification |
| Regulatory status | Prohibited in sport | WADA metabolic modulator class |
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.
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.
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.
Handling recommendations for SR9009 in a laboratory setting include storing the solid at low temperature, protected from light and moisture. The compound is often dissolved in dimethyl sulfoxide or ethanol for experiments. Solutions should be prepared with appropriate personal protective equipment and disposed of according to local rules. Stability data for long-term storage are limited, so stock solutions are typically kept cold and used within defined periods. Records of preparation date and concentration support reproducibility.
SR9009 is not approved as a medicine by major regulatory agencies. It is commonly sold as a research chemical, a category that may fall outside customary drug approval and quality rules. In sports, the World Anti-Doping Agency lists SR9009 as a prohibited substance. Athletes who use it can face sanctions if it is detected in a sample. Legal status varies by country, and importation may be restricted. Enforcement practices differ across borders.
Detection of SR9009 in biological samples usually employs liquid chromatography coupled with tandem mass spectrometry. This method can identify the parent compound and sometimes metabolites in urine or blood. Because exposure can be low and clearance may be rapid, sample timing and limits of detection matter. Laboratories validate assays for sensitivity and specificity. Results are interpreted alongside chain-of-custody and quality-control records. Urine is the common matrix for anti-doping analysis, while blood may be used in research settings.
== External links == AccelrysPKA — Accelrys CHARMm based pKa calculation H++ — Poisson–Boltzmann based pKa calculations MCCE2 — Multi-Conformation Continuum Electrostatics (Version 2) Karlsberg+ — pKa computation with multiple pH adapted conformations PETIT — Proton and Electron TITration GMCT — Generalized Monte Carlo Titration DEPTH web server — Empirical calculation of pKa values using Residue Depth as a major feature
== Early life and education == Schmitt was born in Bridgeton, Missouri, a suburb of St. Louis. He graduated from DeSmet Jesuit High School in 1993 and from Truman State University in 1997, with a BA in political science. At Truman, Schmitt was a member of the Alpha Kappa Lambda fraternity, played football and baseball, and was a founding member of Truman's Habitat for Humanity chapter. He received a scholarship to attend Saint Louis University School of Law, where he earned his JD in 2000.
=== Antibiotics === Physicians often prescribe the antibiotic trimethoprim-sulfamethoxazole to prevent bacterial infections. This drug also has the benefit of sparing the normal bacteria of the digestive tract. Fungal infection is commonly prevented with itraconazole, although a newer drug of the same type called voriconazole may be more effective. The use of this drug for this purpose is still under scientific investigation.
Sources: en.wikipedia.org
In genetics, DNase I hypersensitive sites (DHSs) are regions of chromatin that are sensitive to cleavage by the DNase I enzyme. In these specific regions of the genome, chromatin has lost its condensed structure, exposing the DNA and making it accessible. This raises the availability of DNA to degradation by enzymes, such as DNase I. These accessible chromatin zones are functionally related to transcriptional activity, since this remodeled state is necessary for the binding of proteins such as transcription factors. Since the discovery of DHSs 30 years ago, they have been used as markers of regulatory DNA regions. These regions have been shown to map many types of cis-regulatory elements including promoters, enhancers, insulators, silencers and locus control regions. A high-throughput measure of these regions is available through DNase-Seq.
Interpretation for secondary adrenal insufficiency ACTH will be low – usually below 35, but most people with secondary fall within the range limit. This is inappropriately normal for the low cortisol level. In some cases, the actual cause of low ACTH is from low CRH in the hypothalamus. It is possible to have separate ACTH and CRH impairment such as can happen in a head injury. The ACTH stimulation test is occasionally used to test adrenal production of aldosterone at the same time as cortisol to also help in determining if primary (hyperreninemic) or secondary (hyporeninemic) hypoaldosteronism is present. Human ACTH has a slight stimulatory effect on aldosterone, but the amount of synthetic ACTH given in the stimulation is equivalent to more than a whole days production of natural ACTH, so the aldosterone response can be easily measured in blood serum. Same as cortisol, aldosterone should double from a respectable base value (around 20 ng/dl, must fast salt 24 hours and sit upright for blood draw) in a healthy individual.
It is an amino alcohol and a bioactive sphingoid. Its distinctive trait is that the terminal hydroxy group has been replaced by hydrogen. It possesses antineoplastic properties, appearing to inhibit the proliferation of some kinds of cancer. This sphingoid base can be found, in general, in low levels, in animal cells, and at higher concentrations in the cell membranes of certain bacteria, including Bacteroides species common to the animal gut microbiome—suggesting this as a potential source of these compounds in circulation. It was found for the first time in a marine organism, in which context it is known as spisulosine. It is known by other names such as ES-285. The molecular weight of this compound is 285,5 g/mol and its molecular formula is C18H39NO, which means it has 18 carbons.
Sources: en.wikipedia.org
=== Molecular mechanisms of action === Quisqualic acid is functionally similar to glutamate, which is an endogenous agonist of glutamate's receptors. It functions as a neurotransmitter in insect neuromuscular junction and CNS. It passes the blood brain barrier and binds to cell surface receptors AMPA and Kainate receptors in the brain. AMPA receptor is a type of ionotropic glutamate receptor coupled to ion channels and when bound to a ligand, it modulates the excitability by gating the flow of calcium and sodium ions into the intracellular domain. On the other hand, kainate receptors are less understood than AMPA receptors. Although, the function is somewhat similar: the ion channel permeates the flow of sodium and potassium ions, and to a lower extent the Calcium ions. As mentioned, binding of quisqualic acid to these receptors leads to an influx of calcium and sodium ions into the neurons, which triggers downstream signaling cascades. Calcium signaling involves protein effectors such as kinases (CaMK, MAPK/ERKs), CREB-transcription factor and various phosphatases. It regulates gene expression and may modify the properties of the receptors. Sodium and calcium ions together generate an excitatory postsynaptic potential (EPSP) that triggers action potentials. It's worthwhile to mention that overactivation of glutamate receptors and kainate receptors lead to excitotoxicity and neurological damage. A greater dose of quisqualic acid over activates these receptors that can induce seizures, due to prolonged action potentials firing the neurons.
Potassium is a chemical element; it has symbol K (from Neo-Latin kalium) and atomic number 19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of plants, from which its name derives. In the periodic table, potassium is one of the alkali metals, all of which have a single valence electron in the outer electron shell, which is easily removed to create an ion with a positive charge (which combines with anions to form salts). In nature, potassium occurs only in ionic salts. Elemental potassium reacts vigorously with water, generating sufficient heat to ignite hydrogen emitted in the reaction, and burning with a lilac-colored flame. It is found dissolved in seawater (which is 0.04% potassium by weight), and occurs in many minerals such as orthoclase, a common constituent of granites and other igneous rocks. Potassium is chemically very similar to sodium, the previous element in group 1 of the periodic table. They have a similar first ionization energy, which allows for each atom to give up its sole outer electron. It was first suggested in 1702 that they were distinct elements that combine with the same anions to make similar salts, which was demonstrated in 1807 when elemental potassium was first isolated via electrolysis. Naturally occurring potassium is composed of three isotopes, of which 40K is radioactive.
Upon his return from the U.S., Janež introduced the insulin pump method into clinical practice of treating adult patients with type 1 diabetes in Slovenia. Together with his colleagues from the Department of Endocrinology, Diabetes, and Metabolic Disease at University Medical Centre Ljubljana, Janež co-authored the algorithm used in insulin pump treatment, as well as tutored virtually all Slovenian diabetologists in usage of both insulin pump and glucose sensor. Janež also wrote all of the literature on subjects of functional insulin therapy and insulin pump in Slovenia, with its audiences ranging from diabetologists to patients. In 2008, he established a new unit for functional insulin therapy within the University Medical Centre. Janež also led the effort of forming international standards for interpretation of results obtained with glucose sensor, publishing and presenting these on several international diabetes-related symposiums. Coupled with his previous work in the field of functional insulin therapy and its pilot implementation in Slovenia, Janež went on to introduce this approach to diabetes treatment in other countries.
Dipeptidase 2 (DPEP2) is a protein which in humans is encoded by the DPEP2 gene. DPEP2 belongs to the membrane-bound dipeptidase (EC 3.4.13.19) family. These enzymes hydrolyze a variety of dipeptides, including leukotriene D4, the beta-lactam ring of some antibiotics, and cystinyl-bis-glycine (cys-bis-gly) formed during glutathione degradation.
Sources: en.wikipedia.org
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.
Detection commonly uses liquid chromatography–tandem mass spectrometry. This method can identify the compound in urine or blood at low concentrations.
Typical guidance is −20 °C, dry, and protected from light. Solutions should be aliquoted and limited freeze–thaw cycles should be used.
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.