The short version of NR1D1 fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-07-24. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C20H24ClN3O4S | Reported for the free base |
| Molecular weight | 437.9 g/mol | Calculated from the formula |
| Primary target | REV-ERBα and REV-ERBβ | Nuclear receptors involved in circadian regulation |
| Solubility | Soluble in DMSO and ethanol | Poorly soluble in water |
| Typical storage | -20 °C, desiccated | Protect from light and moisture |
SR9009 is frequently discussed in fitness and research-chemical contexts, yet it has no approved medical indication. Regulatory agencies have not authorized it for human use, and it is not a standard prescription drug. Some sports organizations list it as a prohibited substance because of its potential performance-enhancing properties. Published human data are sparse, so claims about its effects in people often rely on animal models or anecdotal reports. Quality and identity of online materials can vary widely.
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.
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.
In laboratory settings, SR9009 is typically characterized by liquid chromatography–mass spectrometry (LC-MS) or high-performance liquid chromatography with ultraviolet detection (HPLC-UV). These methods can confirm identity and estimate purity, but they require reference standards for accurate quantification. Because SR9009 is not a licensed pharmaceutical, no harmonized pharmacopeial monograph exists. Laboratories often validate in-house methods for matrices such as plasma, urine, or cell culture media. Sample preparation may involve protein precipitation or liquid-liquid extraction before analysis.
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.
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.
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.
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.
Analytical chemists detect SR9009 with liquid chromatography-tandem mass spectrometry, commonly abbreviated LC-MS/MS. Sample preparation may involve protein precipitation, liquid-liquid extraction, or solid-phase extraction before analysis. Laboratories can target the parent compound or its metabolites, depending on the matrix and the purpose of testing. Anti-doping methods require sensitive and specific assays because concentrations in biological samples can be low. Reference standards and validated methods are essential for reliable identification and quantification.
Ciliary neurotrophic factor is a protein that in humans is encoded by the CNTF gene. The protein encoded by this gene is a polypeptide hormone and neurotrophic factor whose actions have mainly been studied in the nervous system where it promotes neurotransmitter synthesis and neurite outgrowth in certain neural populations including astrocytes. It is a hypothalamic neuropeptide that is a potent survival factor for neurons and oligodendrocytes and may be relevant in reducing tissue destruction during inflammatory attacks. A mutation in this gene, which results in aberrant splicing, leads to ciliary neurotrophic factor deficiency, but this phenotype is not causally related to neurologic disease. In addition to the predominant monocistronic transcript originating from this locus, the gene is also cotranscribed with the upstream ZFP91 gene. Cotranscription from the two loci results in a transcript that contains a complete coding region for the zinc finger protein but lacks a complete coding region for ciliary neurotrophic factor. CNTF has also been shown to be expressed by cells on the bone surface, and to reduce the activity of bone-forming cells (osteoblasts).
==== Off-Target Effects of Gene Knockdown ==== Extensive efforts in computational biology have been directed toward the design of successful dsRNA reagents that maximize gene knockdown but minimize "off-target" effects. Off-target effects arise when an introduced RNA has a base sequence that can pair with and thus reduce the expression of multiple genes. Such problems occur more frequently when the dsRNA contains repetitive sequences. It has been estimated from studying the genomes of humans, C. elegans and S. pombe that about 10% of possible siRNAs have substantial off-target effects. A multitude of software tools have been developed implementing algorithms for the design of general mammal-specific, and virus-specific siRNAs that are automatically checked for possible cross-reactivity. Depending on the organism and experimental system, the exogenous RNA may be a long strand designed to be cleaved by Dicer, or short RNAs designed to serve as siRNA substrates. In most mammalian cells, shorter RNAs are used because long double-stranded RNA molecules induce the mammalian interferon response, a form of innate immunity that reacts nonspecifically to foreign genetic material. Mouse oocytes and cells from early mouse embryos lack this reaction to exogenous dsRNA and are therefore a common model system for studying mammalian gene-knockdown effects.
== Regulation == Prolactin cell regulation mainly involves dopamine, a prolactin production suppressor, estrogen, a prolactin production stimulator, and thyrotropin-releasing hormone (TRH), a prolactin release stimulator. Dopamine, the main inhibitor, keeps prolactin levels low. Dopamine is secreted by the hypothalamus during times of high prolactin levels, which in response lowers prolactin levels, a negative feedback mechanism. Estrogen, a stimulator, enhances the production of prolactin. During times of elevated estrogen levels, such as during pregnancy, prolactin production is increased. TRH stimulates the release of prolactin from the pituitary gland. TRH, also released by the hypothalamus, binds to receptors on prolactin cells, activating cellular signaling pathways that promote prolactin secretion.
Dogtooth (Greek: Κυνόδοντας, romanized: Kynodontas) is a 2009 Greek absurdist psychological drama film directed by Yorgos Lanthimos. Written by Lanthimos and Efthymis Filippou, the film is about a husband and wife (Christos Stergioglou and Michelle Valley) who keep their children (Angeliki Papoulia, Christos Passalis, and Mary Tsoni) ignorant of the world outside their property well into adulthood. Dogtooth is Lanthimos's third feature film. It won the Prix Un Certain Regard at the 2009 Cannes Film Festival and was nominated for Best Foreign Language Film at the 83rd Academy Awards. The film gained also notoriety due its many resemblances to the 1972 Mexican film The Castle of Purity. by Arturo Ripstein.
Pd complexes of XPhos catalyze the amination and amidation of arylsulfonates and aryl halides. XPhos has also been used in the Pd-catalyzed borylation of aryl and heteroaryl chlorides Modified versions of XPhos, he more hindered t-BuXPhos and Me4tButylXPhos, have been employed in the formation of diaryl ethers. Incorporation of a sulfonate group at the 4-position allows this ligand to be used for Sonogashira couplings in aqueous biphasic solvents.
Sources: en.wikipedia.org
It is thus crucial to identify the OSA for children with school difficulties; many cases remain unnoticed. Studies have shown that learning skills and behaviors can be improved if the OSA is treated, the neurocognitive and behavioral deficits are thus at least partly reversible. This reversible dimension has been postulated to be negatively correlated to the duration of the symptoms, which would mean that the longer the OSA is left untreated, the less reversible are the consequences.
== Notable cases == Actor Robert Urich died from synovial sarcoma. Folksinger Kate McGarrigle died from clear-cell sarcoma. Actress Michelle Thomas died from desmoplastic small-round-cell tumor, a rare abdominal soft-tissue sarcoma. It Is Written evangelist Henry Feyerabend died from sarcoma in his leg. Video game concept artist Adam Adamowicz died from complications of a rare muscle sarcoma on February 9, 2012, at age 42. Professional wrestler Jake Roberts revealed he has muscle cancer. Professional wrestler Zack Ryder revealed he had synovial sarcoma as a teenager. India's ex-finance minister Arun Jaitley died from sarcoma on August 24, 2019. Writer Rachel Caine died from the disease on November 1, 2020. YouTuber Technoblade died from the disease in June, 2022.
=== Photonics Lab on a Chip === Due to the increase in safety concerns and operating costs of common analytic methods (ICP-MS, ICP-AAS, and ICP-OES), the Photonics Lab on a Chip (PhLOC) is becoming an increasingly popular tool for the analysis of actinides and nitrates in spent nuclear waste. The PhLOC is based on the simultaneous application of Raman and UV-Vis-NIR spectroscopy, which allows for the analysis of more complex mixtures which contain several actinides at different oxidation states. Measurements made with these methods have been validated at the bulk level for industrial tests, and are observed to have a much lower variance at the micro-scale. This approach has been found to have molar extinction coefficients (UV-Vis) in line with known literature values over a comparatively large concentration span for 150 μL via elongation of the measurement channel, and obeys Beer's Law at the micro-scale for U(IV). Through the development of a spectrophotometric approach to analyzing spent fuel, an on-line method for measurement of reactant quantities is created, increasing the rate at which samples can be analyzed and thus decreasing the size of deviations detectable within reprocessing. Through the application of the PhLOC, flexibility and safety of operational methods are increased.
If one of the essential amino acids is not available in the required quantities, protein synthesis will be inhibited, irrespective of the availability of the other amino acids. Protein deficiency has been shown to affect all of the body's organs and many of its systems, for example affecting brain development in infants and young children; inhibiting upkeep of the immune system, increasing risk of infection; affecting gut mucosal function and permeability, thereby reducing absorption and increasing vulnerability to systemic disease; and impacting kidney function. The physical signs of protein deficiency include edema, failure to thrive in infants and children, poor musculature, dull skin, and thin and fragile hair. Biochemical changes reflecting protein deficiency include low serum albumin and low serum transferrin. The amino acids that are essential in the human diet were established in a series of experiments led by William Cumming Rose. The experiments involved elemental diets to healthy male graduate students. These diets consisted of corn starch, sucrose, butterfat without protein, corn oil, inorganic salts, the known vitamins, a large brown "candy" made of liver extract flavored with peppermint oil (to supply any unknown vitamins), and mixtures of highly purified individual amino acids. The main outcome measure was nitrogen balance. Rose noted that the symptoms of nervousness, exhaustion, and dizziness were encountered to a greater or lesser extent whenever human subjects were deprived of an essential amino acid.
== Types of standard solutions == Standard solutions can be categorized by the type of analyte used to prepare them. These analytical standards can either be a primary standard or a secondary standard.
Sources: en.wikipedia.org
It is a synthetic REV-ERB agonist used mainly in preclinical research. It is not an approved medicine for human use.
It binds to REV-ERBα and REV-ERBβ, nuclear receptors involved in circadian and metabolic gene regulation. This can alter transcription of genes related to lipid and glucose metabolism in experimental models.
No controlled human trials have established that effect. Endurance findings come primarily from rodent studies, and human responses remain unknown.
No. It is an investigational compound without approved therapeutic indications. It is sold for research purposes only in many jurisdictions.