The short version of NR1D2 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-12-01 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.
Analytical identification of SR9009 typically relies on liquid chromatography coupled with tandem mass spectrometry. In biological samples, researchers first separate the compound from matrix components using protein precipitation, liquid-liquid extraction, or solid-phase extraction. High-performance liquid chromatography with ultraviolet detection and nuclear magnetic resonance spectroscopy can support structural confirmation of reference materials. Because SR9009 is a small, relatively lipophilic molecule, reverse-phase columns and acidic mobile phases are common. Laboratories often include isotope-labeled internal standards to improve quantification and to correct for ion suppression.
Stability depends on physical form, temperature, light exposure, and solvent. Solid SR9009 is generally stored cold and dry, with protection from light to limit degradation. Dimethyl sulfoxide stocks are common for laboratory work, but repeated freeze-thaw cycles can reduce compound integrity. Aqueous solutions may be less stable than organic stocks, and the ethyl ester in the structure can be susceptible to hydrolysis under certain conditions. Researchers typically validate storage conditions and recheck purity before quantitative experiments, especially when using archived material.
Regulatory treatment of SR9009 varies by country and region. It is not approved as a pharmaceutical, and several jurisdictions restrict its sale for human consumption. Some authorities classify it as a research chemical, a prescription-only substance, or a prohibited performance-enhancing agent in sport. Purchasers may encounter certificates of analysis, but these documents do not guarantee identity, purity, or legality. In research settings, institutional safety reviews and controlled procurement help ensure that materials are handled under appropriate oversight. The absence of harmonized rules means that legal status can change and requires verification.
| 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. |
Physicochemical behavior influences handling. SR9009 is described as a solid with limited aqueous solubility, so organic solvents such as dimethyl sulfoxide or ethanol are common in research stock solutions. Aqueous dilution can produce precipitates if the organic content is too low. Light, heat, and repeated freeze-thaw cycles may affect stability. Storage recommendations usually specify a desiccated freezer environment protected from light, but exact stability data depend on the formulation and matrix.
Detection in biological samples can be complicated by rapid metabolism and low circulating concentrations. Some studies report phase I and phase II metabolites, and analytical methods may need to target those species in addition to the parent compound. Immunoassays are not broadly available, so mass spectrometry remains the main confirmatory approach. For anti-doping testing, laboratories look for SR9009 and its metabolites using validated LC-MS methods. Open questions include how long metabolites remain detectable and how different routes of administration alter detection windows.
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.
inverted repeat A nucleotide sequence followed downstream on the same strand by its own reverse complement. The initial sequence and the reverse complement may be separated by any number of nucleotides, or may be immediately adjacent to each other; in the latter case, the composite sequence is also called a palindromic sequence. Inverted repeats are self-complementary by definition, a property which involves them in many biological functions and dysfunctions. Contrast direct repeat.
=== Bombing of Cambodia === In early 1969, Kissinger was opposed to the plans for Operation Menu, the bombing of Cambodia, but on 16 March 1969 Nixon at a meeting at the White House attended by Kissinger announced the bombing would start the next day. As Congress was unlikely to grant approval to bomb Cambodia, Nixon decided to go ahead without Congressional approval and kept the bombings secret, a decision that several constitutional law experts later argued was illegal. On 17 March 1969, B-52 bombers started to bomb the supposed location of the COSVN in an operation code-named Breakfast; Kissinger stated later that he found the name Operation Breakfast be in bad taste. Though Kissinger had initially opposed Operation Menu, he started to champion the bombing. In May 1969, the Operation Menu bombing of Cambodia was leaked to journalist William M. Beecher of the New York Times who published an article about it, which infuriated Kissinger. As a result, the phones of 13 members of Kissinger's staff were tapped by the FBI without a warrant to find the leaker. Nixon considered Kissinger to be "obsessive and paranoid" and was annoyed with his endless in-fighting with Laird and Rogers. Kissinger accused Laird of leaking Operation Menu.
=== Australia === The following programs of study have currently been approved by the Dental Board of Australia for the profession of dental prosthetics. On successful completion of the selected courses, individuals are required to register with the Australian Health Practitioner Regulation Agency to practice legally as a dental prosthetist.
Sources: en.wikipedia.org
=== Transporters of small hydrophobic molecules === These peripheral proteins function as carriers of non-polar compounds between different types of cell membranes or between membranes and cytosolic protein complexes. The transported substances are phosphatidylinositol, tocopherol, gangliosides, glycolipids, sterol derivatives, retinol, fatty acids, water, macromolecules, red blood cells, phospholipids, and nucleotides.
are about 0.01-0.1 nanometers (Table 1). Hence, a high-resolution model of liquid structure at the nanoscale may require quantum mechanical considerations. A notable example is hydrogen bonding in associated liquids like water, where, due to the small mass of the proton, inherently quantum effects such as zero-point motion and tunneling are important. For a liquid to behave classically at the macroscopic level,
There is an increased possibility of protein deficiency with a strictly vegetable diet, unless the vegetable sources are carefully combined so that they complement one another. In 1985, the principle of protein combining was explained by J. Rigó:
LSD (lysergic acid diethylamide; lysergide) is a derivative of lysergic acid, which is obtained from the hydrolysis of ergotamine. Ergotamine is an alkaloid found in the fungus Claviceps purpurea (ergot), which primarily infects rye. LSD is both the prototypical psychedelic and the prototypical lysergamide. As a lysergamide, LSD contains both a tryptamine and phenethylamine group within its structure. Uniquely among psychedelics, LSD agonises dopamine receptors as well as serotonin receptors. Drugs like ALD-52 (1A-LSD), 1P-LSD, and 1V-LSD are prodrugs of LSD. Psilocin (4-HO-DMT) is the dephosphorylated active metabolite of the indole alkaloid psilocybin (4-PO-DMT) and a substituted tryptamine, which is produced by hundreds of species of psilocybin-containing mushrooms. Of the classical psychedelics, psilocybin has attracted the greatest academic interest regarding its ability to manifest mystical experiences, although all psychedelics are capable of doing so to variable degrees. 4-AcO-DMT (O-acetylpsilocin or psilacetin) is a synthetic acetylated analogue of psilocin and is a prodrug of psilocin similarly to psilocybin. Mescaline (3,4,5-trimethoxyphenethylamine) is a phenethylamine alkaloid found in various species of cacti, the best-known of these being peyote (Lophophora williamsii) and the San Pedro cactus (Echinopsis pachanoi, syn. Trichocereus macrogonus var. pachanoi). Mescaline has effects comparable to those of LSD and psilocybin.
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.
The most common approach is liquid chromatography-tandem mass spectrometry, often after extraction from blood, urine, or tissue. Ultraviolet detection and nuclear magnetic resonance spectroscopy are used mainly for reference material characterization. Isotope-labeled internal standards improve accuracy.