reference standard comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-03-30. Where a claim depends on a specific study, the study is described rather than over-claimed.
Laboratory identification of SR9009 typically relies on chromatographic separation coupled to mass spectrometry, often with ultraviolet detection as a secondary check. Nuclear magnetic resonance spectroscopy can confirm molecular structure when a reference standard is available. Because many suppliers sell the compound as a research chemical, independent identity testing is important for experimental reproducibility. A single retention time is not sufficient proof of identity, especially when related compounds may be present. Purity assessments usually report a percentage based on area normalization.
SR9009 is generally described as poorly soluble in water and more soluble in organic solvents such as dimethyl sulfoxide and ethanol. Stock solutions are commonly prepared in an organic solvent before dilution into an aqueous buffer or vehicle. Precipitation can occur if the organic fraction is reduced too quickly or if the final concentration exceeds the compound's solubility limit. Sonication or gentle warming may aid dissolution in some protocols, but excessive heat can promote degradation. Container material and pH can also influence observed solubility.
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 |
|---|---|---|
| Appearance | White to off-white powder | Visual inspection is not sufficient for identity. |
| Solubility | Soluble in DMSO and ethanol | Low solubility in water; stock solutions use organic solvent. |
| Storage | -20°C, desiccated, protected from light | Limits hydrolysis and photodegradation. |
| Analytical method | HPLC-UV/MS | Used for identity and purity assessment. |
| Synonyms | SR9009, Stenabolic | Naming varies by supplier. |
At the molecular level, SR9009 binds REV-ERBα and REV-ERBβ and alters their repressive activity on target genes. These nuclear receptors help regulate the circadian clock, lipid synthesis, glucose metabolism, and inflammatory pathways. By changing transcription, the compound can shift the timing or magnitude of downstream metabolic processes in model systems. It does not act through androgen receptors or adenosine receptors, which distinguishes it from several substances sold for athletic performance. Whether the same transcriptional changes occur in humans at tolerable exposures remains an open question because controlled human studies are lacking.
Preclinical reports describe effects on exercise endurance, mitochondrial content, and lipid profiles in rodents, but these findings come from specific experimental conditions. Many studies use high doses or delivery methods that may not translate directly to human use. SR9009 has been reported to have low oral bioavailability and a short half-life, which complicates interpretation of oral dosing studies. It is not established as safe or effective for any indication. Literature discussions often separate its pharmacological mechanism from unverified claims made in fitness and supplement markets.
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.
== Further reading == ABC News gallery of Cheese seized by the Dallas ISD Pantazi, Andrew. "‘Cheese’ heroin led Dallas 13-year-old to a life on the edge." The Dallas Morning News. 29 December 2012. Updated 30 December 2012. Dave Montgomery. "Law enforcement worries 'cheese heroin' could spread," McClatchy Newspapers, July 18, 2007. Maxwell, Jane C., PhD (Senior Research Scientist, University of Texas at Austin Gulf Coast Addiction Technology Transfer Center). "“Cheese” Heroin: Status as of May 2, 2007" (Archive) Merlan, Anna. "In Suburban Dallas, Loosening "Cheese" Heroin's Deadly Grip Archived 2013-10-13 at the Wayback Machine." Dallas Observer. July 28, 2011. Merlan, Anna. "Why Does Dallas Keep Forgetting About its Cheese-Heroin Problem? Archived 2012-12-24 at the Wayback Machine" Dallas Observer. May 21, 2012. "Dallas Man Sentenced to a Total of 240 Months in Federal Prison for Role in Heroin Distribution Conspiracies." (Archive[link removed]) United States Department of Justice. November 5, 2013. Tracy Sabo. "Deadly $2 heroin targets teens," CNN, June 12, 2007. "New Drug Hits the Street? A 'Poor Man's Heroin' For Kids", Pine Magazine, June 12, 2007.
Ripasudil had no effect on respiratory or neurological function. Although no carcinogenicity studies were performed on the drug, developers believed it to be non-carcinogenic due to its rapid elimination and therefore lack of accumulation in tissue, as well as the lack of inflammatory response in the eye post-administration.
Similarly, a base such as spermine has more than one site where protonation can occur. For example, mono-protonation can occur at a terminal −NH2 group or at internal −NH− groups. The Kb values for dissociation of spermine protonated at one or other of the sites are examples of micro-constants. They cannot be determined directly by means of pH, absorbance, fluorescence or NMR measurements; a measured Kb value is the sum of the K values for the micro-reactions.
Sources: en.wikipedia.org
=== Symptomatic diagnostics === The diagnosis is aided by the presenting symptoms in any individual with an infectious disease, yet it usually needs additional diagnostic techniques to confirm the suspicion. Some signs are specifically characteristic and indicative of a disease and are called pathognomonic signs; but these are rare. Not all infections are symptomatic. In children the presence of cyanosis, rapid breathing, poor peripheral perfusion, or a petechial rash increases the risk of a serious infection by greater than 5 fold. Other important indicators include parental concern, clinical instinct, and temperature greater than 40 °C.
=== 5 June === Ukrainian forces were reported to be advancing towards Bakhmut, with the Wagner Group's Yevgeny Prigozhin confirming that Ukrainian soldiers had retaken part of the settlement of Berkhivka, north of the city. Hanna Malyar, Ukrainian Deputy Defence Minister said that 'offensive actions' were underway in "some areas" in eastern Ukraine, adding that Ukrainian troops gained from 200 to 1,600 meters (660 to 5,250 ft) in Orikhovo-Vasulivka and Paraskoviivka, while in Ivanivske and Klishchiivka they advanced between 100 and 700 meters (330 and 2,300 ft). The Russian defense ministry said it was holding back attacks by Ukrainian forces near the settlements of Novodonetske and Oktyabrske. The Ukrainian government accused Russia of violating the terms of the Black Sea Grain Initiative by registering two vessels that declared their participation in the deal the same day, adding it went against accepted vessel inspection rules that required priority inspection and registration of longer-standing ships. The Wagner Group said it had detained a regular Russian military officer who opened fire on one of their vehicles near Bakhmut. The officer was said to have disliked the group and attacked the vehicle while intoxicated. The officer was later identified as Lt. Col. Roman Venevitin, who was later released and subsequently accused the group of stoking "anarchy" on Russia's frontlines by stealing arms, forcing mobilized soldiers to sign contracts with the group and attempting to extort weapons from the defence ministry.
A common natural contaminant, DS is present at levels of 1–7% in heparin API but has no proven biological activity that influences the anticoagulation effect of heparin. In December 2007, the US Food and Drug Administration (FDA) recalled a shipment of heparin because of bacterial growth (Serratia marcescens) in several unopened syringes of this product. S. marcescens can lead to life-threatening injuries and/or death.
== Applications == Applications include alteration of gene expression - both as inhibitor and promoter in different cases, antigene and antisense therapeutic agent, anticancer agent, antiviral, antibacterial and antiparasitic agent, molecular tools and probes of biosensor, detection of DNA sequences, and nanotechnology. PNAs can be used to improve high-throughput 16S ribosomal RNA gene sequencing of plant and soil samples by blocking amplification of contaminant plastid and mitochondrial sequences. Cellular – Functional Antagonism/Inhibition. In 2001, Strauss and colleagues reported the design of an application for PNA oligomers in living mammalian cells. The Xist chromatin binding region was first elucidated in female mouse fibroblastic cells, and embryonic stem cells though the use of a PNA molecular antagonist. The novel PNA approach directly demonstrated function of a lncRNA. The long non-coding (lncRNA) RNA, Xist directly binds to the inactive X-chromosome. Functional PNA inhibition experiments revealed that specific repeat regions of the Xist RNA were responsible for chromatin binding, and hence could be considered domain regions of the RNA transcript. The PNA molecular antagonist was administered to living cells and functionally inhibited the association of Xist with inactive X-chromosome using the approach for studying noncoding RNA function in living cells called peptide nucleic acid (PNA) interference mapping. In the reported experiments, a single 19-bp antisense cell-permeating PNA targeted against a particular region of Xist RNA caused the disruption of the Xi.
Sources: en.wikipedia.org
In pharmacology, the international unit (IU) is a unit of measurement for the effect or biological activity of a substance, for the purpose of easier comparison across similar forms of substances. International units are used to quantify vitamins and biologics (hormones, some medications, vaccines, blood products and similar biologically active substances). International units as used in pharmacology are not part of the International System of Units (SI).
== Scope == By convention of the nomenclature system, members within an individual SLC family have greater than 20-25% sequence identity to each other. In contrast, the homology between SLC families is very low to non-existent. Hence, the criteria for inclusion of a family into the SLC group is not evolutionary relatedness to other SLC families but rather functional (i.e., an integral membrane protein that transports a solute). The SLC group include examples of transport proteins that are:
The city of Le Havre has some of the oldest sports clubs in France: the Le Havre Rowing Society (1838), the Regatta Society of Le Havre (1838), and Le Havre Athletic Club (1872), doyen of French football and rugby clubs. The city also hosted the sailing events for the 1900 and 1924 Summer Olympics, respectively. Le Havre is dominated by three professional sports teams: the first is the Le Havre AC football team who were relegated from Ligue 1 after the 2008–2009 season but gained promotion back to Ligue 1 in 2023. Its training centre is well-reputed for having trained a number of international French players, including Vikash Dhorasoo, Julien Faubert, Jean-Alain Boumsong, Lassana Diarra, and Steve Mandanda. The second major sports team is Saint Thomas Basketball who represent the city in LNB Pro A. Thirdly the HAC women's team who play in the first division with many international players in its ranks. The team won their first major national title, the Coupe de France for women's handball in 2006. Le Havre Rugby athletic club plays in Fédérale 3 (equivalent to fifth division). The Hockey Club of Le Havre played at the fourth level nationally (Division 3) for the 2008–2009 season. The team is nicknamed the "Dock's du Havre". The maritime side of the city is found in many sports: for example, the tradition of sailing is old. On 29 July 1840 the first French pleasure boat regatta was held. Today, Le Havre is known as a water sports and Seaside resort. The marina can host deepwater vessels around the clock in any weather.
== Human uses == Human uses of AGPs include the use of Gum arabic in the food and pharmaceutical industries because of natural properties in thickening and emulsification. AGPs in cereal grains have potential applications in biofortification, as sources of dietary fibre to support gut bacteria and protective agents against ethanol toxicity.
Polyphenols comprise up to 0.2–0.3% fresh weight for many fruits. Consuming common servings of wine, chocolate, legumes or tea may also contribute to about one gram of intake per day. According to a 2005 review on polyphenols:
Sources: en.wikipedia.org
Liquid chromatography with mass spectrometry is a common approach. Ultraviolet detection and nuclear magnetic resonance can support identification when suitable standards are available.
The solid is generally kept cold, dry, and protected from light. Solutions are often frozen in single-use aliquots to reduce repeated freeze-thaw cycles.
It indicates a material sold for laboratory study, not for human use. The label does not guarantee pharmaceutical purity, sterility, or regulatory approval.
No. It is an investigational compound without approved therapeutic indications. It is sold for research purposes only in many jurisdictions.