REV-ERB raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-02-09. Anything still debated is marked as such rather than presented as settled.
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.
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 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 | Off-white to pale yellow solid | Visual description varies with purity and source |
| Solubility | Soluble in DMSO and ethanol; poorly soluble in water | Organic stock solutions are common in research |
| Typical storage | -20 °C, desiccated, protected from light | Avoid repeated freeze-thaw cycles |
| Typical analytical method | LC-MS or HPLC-UV | Reference standards are needed for quantification |
| Molar mass | Approximately 437.9 g/mol | Calculated from the reported free-base formula |
SR9009 binds REV-ERB receptors and alters their repressive activity on target genes. This action can change transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. In rodent studies, treated animals have shown changes in muscle oxidative capacity and exercise performance, though effects vary by dose, duration, and model. The precise molecular steps connecting receptor binding to whole-body outcomes are still an active area of investigation. Findings in animals do not automatically translate to humans.
Because REV-ERB receptors are core clock components, SR9009 has been examined for effects on daily rhythms as well as metabolism. Research has explored whether the compound can shift or reinforce circadian gene expression in tissues such as liver and muscle. Some studies report improved metabolic markers in obese or diabetic mice, while others show context-dependent responses. Questions remain about which effects are direct, which are secondary to timing, and how they might differ across species.
SR9009 is a synthetic small molecule studied as an agonist of REV-ERB nuclear receptors. REV-ERB alpha and REV-ERB beta help regulate circadian rhythms and metabolic gene expression. In laboratory research, SR9009 has been used to probe how these receptors affect skeletal muscle, liver, and adipose tissue. The compound was identified in academic drug-discovery work and is often described in scientific literature by its chemical name and research code. It is not an approved medicine, and human clinical data remain limited or absent.
Detection of SR9009 in biological samples usually relies on liquid chromatography coupled to tandem mass spectrometry. This approach separates the compound from matrix components and identifies it by mass transitions. Because SR9009 can undergo metabolism, laboratories often look for both parent drug and specific metabolites. Sample preparation may involve protein precipitation or solid-phase extraction. Method validation examines sensitivity, carryover, and interference from related substances, and reference standards are required for accurate calibration.
Storage recommendations for SR9009 reference material typically specify a freezer at -20 °C or lower, with protection from moisture and light. Repeated freeze-thaw cycles can degrade small molecules and introduce variability. Stock solutions in dimethyl sulfoxide are often aliquoted to avoid repeated handling. Stability studies may examine degradation under heat, humidity, and light exposure. The compound's thiophene and nitro groups can participate in reactions that alter analytical signals over time, so such changes affect quantitative results.
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.
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.
==== Incidents ==== On 9 June 1973, William Penn Patrick (43) a certified pilot and his passenger, Christian Hagert, died when Patrick's P-51 Mustang crashed in Lakeport, California. On 1 July 1990 at the National Capital Air Show (Ottawa, Ontario, Canada), Harry E. Tope was killed when his P-51 Mustang crashed. On 16 September 2011 The Galloping Ghost, a modified P-51 piloted by Jimmy Leeward of Ocala, Florida, crashed during an air race in Reno, Nevada. Leeward and at least nine people on the ground were killed when the racer suddenly crashed near the edge of the grandstand.
== Diagnosis == CIP and CIM are a major cause of ICU-acquired weakness (ICUAW). Current guidelines recommend a clinical diagnosis of ICUAW, made by manually testing the muscle strength with the use of the Medical Research Council (MRC) sum score or handgrip dynamometry. CIP/CIM is often not identified until a patient is unable to be successfully weaned from a mechanical ventilator. Early detection of the condition is difficult, because these patients are often sedated and intubated, and thus unable to cooperate with a thorough neuromuscular physical examination. The use of conventional nerve conduction studies is time-consuming and requires specialized personnel; however, simplified electrophysiologic tests can be used as screening tools in the critically ill to confirm or exclude CIP/CIM. The peroneal nerve test is a validated, high-sensitivity, minimally invasive, non-volitional and quick diagnostic test which can accurately exclude CIP/CIM if the result is normal. Moreover, patients with disuse atrophy and muscle deconditioning have normal electrophysiological tests even if muscle strength is severely reduced Hence, these tests are important to define the cause of muscle weakness and can be helpful to refine the prognosis.
American Association of Physical Anthropologists Biological Anthropology Section of the American Anthropological Association British Association of Biological Anthropologists and Osteoarchaeologists Canadian Association for Physical Anthropology Journals
=== "Merck" name legal dispute === In 191 of 193 countries, the original Merck company, the Merck Group of Darmstadt, owns the rights to the "Merck" name. In the United States and Canada, the company trades under the name EMD (an abbreviation of Emanuel Merck, Darmstadt), its legal name here says Merck KGaA, Darmstadt, Germany, and instead of "Merck Group", the "EMD Group" name is used. In the United States and Canada, Merck & Co. holds the rights to the trademark "Merck", while in the rest of the world the company trades under the name MSD (an abbreviation of Merck, Sharp & Dohme) and its legal name says here Merck Sharp & Dohme LLC., a subsidiary of Merck & Co., Inc. Kenilworth, NJ, USA. In 2015 the Merck Group adopted a new logo and said it will be "much more aggressive" about protecting the brand of "the real Merck". Merck of Darmstadt has initiated litigation against its former subsidiary, Merck & Co. (MSD) of Kenilworth, in several countries over infringing use of the Merck name. In 2016, the High Court of Justice in the United Kingdom ruled that MSD had breached an agreement with its former parent company and that only Merck of Darmstadt is entitled to use the Merck name in the United Kingdom. The judge also held that MSD's use of "Merck" as part of branding on its global websites were directed to the UK and infringed Merck's trade mark rights in the UK.
== Banned anabolic agents == Banned anabolic agents are, for the purpose of WADA, either anabolic steroids, which activate testosterone and epitestosterone receptors, thereby improving muscle strength and endurance, or "other anabolic agents". Andro, DHEA, stanozolol, testosterone, and nandrolone, or derivates (see below) are banned anabolic steroids. Other banned anabolic agents include clenbuterol, tibolone, zeranol, zilpaterol, and selective androgen receptor modulators. While a few of the banned drugs are endogenous, that is they are normally produced in the human body, most of the banned drug are exogenous drugs chemically produced. These types of drugs were used extensively in Major League Baseball in the 1990s and early 2000s.
Sources: en.wikipedia.org
Etschkreis: roughly the modern Trentino province Eisackkreis: roughly the modern East Tyrol excluding Matrei and South Tyrol excluding the westernmost upper Etsch valley around Glurns Innkreis: roughly North Tyrol plus the upper Etsch valley and excluding the Zillertal and Brixental (which were part of Salzburg)
== Dietary recommendations == The US National Academy of Medicine updated Dietary Reference Intakes (DRIs) in 2001 for vitamin A, which included Recommended Dietary Allowances (RDAs). The tolerable upper intake level (UL) is 3000 μg/day. For children ages 1-3 years the vitamin A RDA and UL are 300 and 600 μg/day, respectively, for children ages 4-8 years 400 and 900 μg/day. People consuming cod liver oil as a source of omega-3 fatty acids should pay attention to how much vitamin A and vitamin D this adds to their diet. For infants up to 12 months, there was not sufficient information to establish an RDA, so Adequate Intake (AI) is shown instead. As for safety, tolerable upper intake levels (ULs) were also established. For ULs, carotenoids are not added when calculating total vitamin A intake for safety assessments.
The Helvetic Republic was set up by France when it invaded Switzerland in 1798. France had withdrawn its troops, but violent strife broke out against the government, which many Swiss saw as overly centralised. Bonaparte reoccupied the country in October 1802 and imposed a compromise settlement. This caused widespread outrage in Britain, which protested that this was a violation of the Treaty of Lunéville. Although continental powers were unprepared to act, the British decided to send an agent to help the Swiss obtain supplies, and also sent secret orders to the Cape Colony to prevent a Dutch takeover. Swiss resistance collapsed before anything could be accomplished, and, after a month, Britain countermanded the orders to not restore Cape Colony. At the same time, Russia finally joined the guarantee regarding Malta. Concerned that there would be hostilities when Bonaparte found out that Cape Colony had been retained, the British began to procrastinate on the evacuation of Malta. In January 1803, a government paper in France published a report from a commercial agent which noted the ease with which Egypt could be conquered. The British seized on this to demand satisfaction and security before evacuating Malta, which was a convenient stepping stone to Egypt. France disclaimed any desire to seize Egypt and asked what sort of satisfaction was required, but the British were unable to give a response. There was still no thought of going to war; Prime Minister Henry Addington publicly affirmed that Britain was in a state of peace.
== S == Sac6 Sla1p Srv2 (CAP) S-adenosyl-L-homocysteine hydrolase, (SAHH) Sla2p Synaptopodin Scinderin (adseverin) Synapsins Scruin Spectrin Severin Spectraplakins SVSII Shot (Short stop) Spire Shroom Smitin (Smooth Musc.Titin) Supervillin SipA Smoothelin Sucrose synthetase SipC Sra-1 Spinophilin Ssk2p Swinholide
Sources: en.wikipedia.org
It is usually detected by LC-MS or HPLC-UV against a reference standard. In biological matrices, metabolite targeting can improve detection. No universal immunoassay is widely available.
The compound is generally handled as light-sensitive and stored cold and dry. Stability in solution depends on solvent, concentration, and storage time. Specific degradation rates are not fully standardized.
Limited water solubility affects formulation for cell and animal studies. Organic co-solvents are often used to dissolve it. Precipitation can confound assay results if not controlled.
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.