A practical reference on reference standard: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-11-11 and is reviewed periodically as new material appears.
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.
REV-ERB proteins help regulate daily cycles in gene expression, including genes tied to lipid and glucose metabolism. SR9009 binds these receptors and alters their activity in cell and animal experiments. Consequences observed in rodents include changes in skeletal muscle oxidative capacity, blood lipid levels, and exercise performance. The precise chain from receptor occupancy to whole-body effects is still an active area of study. Human responses cannot be assumed from rodent data.
Most published work on SR9009 consists of preclinical studies. It is widely sold as a research chemical, a category that does not imply safety, efficacy, or pharmaceutical-grade quality. Sports anti-doping organizations have listed SR9009 as a prohibited substance, and its presence in an athlete sample can lead to sanctions. Legal status differs by country; in several jurisdictions it is not approved for human consumption and may be treated as an unapproved new drug.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic REV-ERB agonist | Binds REV-ERBα and REV-ERBβ in preclinical models |
| Molecular formula | C20H24ClN3O4S | Reported for the parent compound |
| CAS Registry Number | 1379686-30-2 | Common identifier in chemical databases |
| Appearance | Off-white to pale yellow solid | Typical research chemical solid |
| Solubility | Soluble in DMSO and ethanol; low in water | Class: small organic molecule |
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.
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.
Handling practices for SR9009 focus on minimizing degradation and contamination. The solid is generally stored desiccated at or below -20 °C, protected from light and moisture. Stock solutions are often prepared in dimethyl sulfoxide or ethanol, then aliquoted to avoid repeated freeze–thaw cycles. Aqueous solubility is low, so formulations for animal studies may require cosolvents or suspending agents. Personnel should follow institutional chemical safety procedures, because toxicological data for humans are incomplete.
Regulatory status varies by country and intended use. Major drug agencies have not granted marketing authorization for SR9009 as a medicine, and it is not listed as a controlled substance in many jurisdictions. It is often sold as a research chemical, a category that may fall outside pharmaceutical manufacturing rules. Buyers should verify local laws and supplier documentation, including certificates of analysis. The lack of standardized quality controls raises concerns about identity, purity, and actual content in products marketed online.
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.
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.
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.
== Caesium-134 == Caesium-134 has a half-life of 2.0650 years. It is produced both directly (at a very small yield because 134Xe is stable) as a fission product and via neutron capture from nonradioactive 133Cs (neutron capture cross section 29 barns), which is a common fission product. It is not produced by nuclear weapons because 133Cs is created by beta decay of original fission products long after the nuclear explosion is over. The combined yield of 133Cs and 134Cs is given as 6.7896%. The proportion between the two will change with continued neutron irradiation. 134Cs also captures neutrons with a cross section of 140 barns, becoming long-lived radioactive 135Cs. Caesium-134 undergoes beta decay (β−), producing stable 134Ba after emitting on average 2.23 gamma ray photons (mean energy 0.698 MeV).
Later works of James Prescott Joule, Rudolf Clausius and in particular Ludwig Boltzmann firmly established the kinetic theory of gases and brought attention to both the theories of Bernoulli and Waterston. The debate between proponents of energetics and atomism led Boltzmann to write a book in 1898, which endured criticism until his suicide in 1906. Albert Einstein in 1905 showed how kinetic theory applies to the Brownian motion of a fluid-suspended particle, which was confirmed in 1908 by Jean Perrin.
== Third round proper == The draw for the third round was made on 28 November 2022, consisting of the 20 winners from the previous round, all 20 members of the Premier League and the 24 EFL Championship clubs. The round included three teams from the fifth tier, the lowest-ranked teams remaining in the competition: Chesterfield, Boreham Wood, and Wrexham.
== Ergothioneine derivatives == Various derivatives of ergothioneine have been reported in the literature, such as S-methyl-ergothioneine or selenium-containing selenoneine. The latter is made using the same biosynthetic pathway as ergothioneine when selenocysteine is present.
Sources: en.wikipedia.org
== Signs and symptoms == MODY accounts for at least 1-5% of all diagnoses of diabetes mellitus, though 50-90% of cases are estimated to be misdiagnosed as type 1, or type 2 diabetes. Estimated prevalence rates indicate 1 per 10,000 in adults, and 1 per 23,000 in children. 50% of first-degree relatives will inherit the same mutation, giving them a greater than 95% lifetime risk of developing MODY themselves. For this reason, correct diagnosis of this condition is important. Typically patients present with a strong family history of diabetes (i.e.: presence of diabetes before the age of 25 in two consecutive generations). There are two general types of clinical presentation.
EDE was available only in combination EB and TEBH. The combination was available in two different dose forms, one for menopausal hormone therapy (brand names Climacteron, Amenose) and the other for lactation suppression (brand names Lactimex, Lactostat). Climacteron and Amenose contained 1.0 mg EB, 7.5 mg EDE, and 150 mg TEBH (69 mg free testosterone) and was given by repeated intramuscular injection at regular intervals. Lactimex and Lactostat contained 6 mg EB, 15 mg EDE, and 300 mg TEBH in 2 mL of corn oil and was administered as a single intramuscular injection after childbirth or during breastfeeding.
== Pathophysiology == Ochronosis occurs because of deposition of phenols (such as homogentisic acid and hydroquinone) as plaques in the matrix of cartilage. The pigments can also be incorporated into collagen and elastin fibers. In the skin, the pigment alters the structure of the fibers, causing enlargement and curling. The embedded pigments also form crosslinks with pigment depositions in adjacent fibers, stabilizing and reducing the elastic recoil of the fibers. This results in hardening of elastic structures, increasing their rigidity and brittleness. Once ruptured, the exposed pigments cause a foreign body reaction and inflammation. This pigment deposition also invokes deposition of hydroxyapatite, the mineral responsible for bone calcification, further hardening the connective tissue. The pigment can also be excreted by glandular cells in apocrine and ceruminous sweat glands, as well as breast and prostate tissue. This results in darkly pigmented sweat and breast milk. Excretion of the pigment is only found in endogenous ochronosis and should not occur from topical phenols.
In 2022, he rejoined his former departments at Harvard and the Dana–Farber Cancer Institute. Cantley is married to Vicki Sato, herself a prominent figure in the pharmaceutical industry and a professor at Harvard University in both the Business and Medical Schools.
Antipredatory defensive behavior Exposure to a predator (such as a cat) elicits defensive behaviors in laboratory rodents, even when the animal has never been exposed to a cat. In the hypothalamus, this exposure causes an increase in Fos-labeled cells in the anterior hypothalamic nucleus, the dorsomedial part of the ventromedial nucleus, and in the ventrolateral part of the premammillary nucleus (PMDvl). The premammillary nucleus has an important role in expression of defensive behaviors towards a predator, since lesions in this nucleus abolish defensive behaviors, like freezing and flight. The PMD does not modulate defensive behavior in other situations, as lesions of this nucleus had minimal effects on post-shock freezing scores. The PMD has important connections to the dorsal periaqueductal gray, an important structure in fear expression. In addition, animals display risk assessment behaviors to the environment previously associated with the cat. Fos-labeled cell analysis showed that the PMDvl is the most activated structure in the hypothalamus, and inactivation with muscimol prior to exposure to the context abolishes the defensive behavior. Therefore, the hypothalamus, mainly the PMDvl, has an important role in expression of innate and conditioned defensive behaviors to a predator.
Sources: en.wikipedia.org
SR9009 is a synthetic small molecule studied as an agonist of the REV-ERB nuclear receptors. It is not an approved medicine, and its effects in humans are not well characterized.
No. It is a synthetic ligand that binds nuclear receptors, not a steroid or peptide hormone. Its activity depends on receptor binding rather than endocrine secretion.
Clinical evidence is limited. Most published data come from cell and animal experiments. Human safety and efficacy remain uncertain.
It is a synthetic compound studied as an agonist of REV-ERB nuclear receptors. It is not an approved medicine and has mainly been examined in laboratory and animal research.