If you have been reading about WADA and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-03-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Not approved for human use | Research-use-only status in many markets |
| WADA status | Prohibited in sport | Generally listed as a non-approved substance |
| Detection technique | LC-MS/MS | Common for urine and blood analysis |
| Common alias | Stenabolic | Informal market nickname, not a pharmacopoeial name |
| Purity check | HPLC or LC-UV | Independent certificate of analysis is typical |
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.
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.
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.
2 oxidized rubredoxin + NADH The 3 substrates of this enzyme are reduced rubredoxin, NAD+, and H+, whereas its two products are oxidized rubredoxin and NADH. This enzyme belongs to the family of oxidoreductases, specifically those acting on iron-sulfur proteins as donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is rubredoxin:NAD+ oxidoreductase. Other names in common use include rubredoxin reductase, rubredoxin-nicotinamide adenine dinucleotide reductase, dihydronicotinamide adenine dinucleotide-rubredoxin reductase, reduced nicotinamide adenine dinucleotide-rubredoxin reductase, NADH-rubredoxin reductase, rubredoxin-NAD reductase, NADH: rubredoxin oxidoreductase, DPNH-rubredoxin reductase, and NADH-rubredoxin oxidoreductase. This enzyme participates in fatty acid metabolism. It has 2 cofactors: FAD and Iron.
A recombinant fusion protein is a protein created through genetic engineering of a fusion gene. This typically involves removing the stop codon from a cDNA sequence coding for the first protein, then appending the cDNA sequence of the second protein in frame through ligation or overlap extension PCR. That DNA sequence will then be expressed by a cell as a single protein. The protein can be engineered to include the full sequence of both original proteins, or only a portion of either. If the two entities are proteins, often linker (or "spacer") peptides are also added, which make it more likely that the proteins fold independently and behave as expected. Especially in the case where the linkers enable protein purification, linkers in protein or peptide fusions are sometimes engineered with cleavage sites for proteases or chemical agents that enable the liberation of the two separate proteins. This technique is often used for identification and purification of proteins, by fusing a GST protein, FLAG peptide, or a hexa-his peptide (6xHis-tag), which can be isolated using affinity chromatography with nickel or cobalt resins. Di- or multimeric chimeric proteins can be manufactured through genetic engineering by fusion to the original proteins of peptide domains that induce artificial protein di- or multimerization (e.g., streptavidin or leucine zippers). Fusion proteins can also be manufactured with toxins or antibodies attached to them in order to study disease development.
=== Solvation === Many liquids are used as solvents, to dissolve other liquids or solids. Solutions are found in a wide variety of applications, including paints, sealants, and adhesives. Naphtha and acetone are used frequently in industry to clean oil, grease, and tar from parts and machinery. Body fluids are water-based solutions. Surfactants are commonly found in soaps and detergents. Solvents like alcohol are often used as antimicrobials. They are found in cosmetics, inks, and liquid dye lasers. They are used in the food industry, in processes such as the extraction of vegetable oil.
Venezuelan defense minister Vladimir Padrino López said that US combat helicopters fired rockets and missiles in urban areas and that officials were working to gather information on the number of fatalities and injuries. Padrino López also stated that most of Maduro's personal guard were killed during the attack. The New York Times reported on 3 January 2026 that an anonymous Venezuelan official said at least 40 people, including civilians and military personnel, were killed in the attack, updated to 80 on 4 January, "according to a senior Venezuelan official". Independent Venezuelan journalistic reports confirmed that most Venezuelan dead were among members of the presidential guard, with two civilian deaths. The presence of Cuban troops in Venezuela was made public after the attack. Their presence was denied as far back as 2008. In 2019 Maduro had claimed in an interview that no Cuban military personnel were stationed in the country and that his personal guard was Venezuelan. Trump indicated that Cuban forces were involved in the operation, stating: "You know, a lot of Cubans were killed yesterday." The government of Cuba reported that 32 Cubans were killed in Venezuela, all members of armed forces and intelligence services. One of the most senior Cuban soldiers that died, Colonel Humberto Roca, was responsible for Fidel Castro's security in the past. According to Reuters reporting in February, anonymous Venezuelan officials indicated that some Cuban security forces and medical doctors in Venezuela were returning to Cuba, diminishing their role in Venezuelan politics.
Sources: en.wikipedia.org
This topographic architecture extends to the NAcc core, where KOR-mediated dopamine inhibition similarly manifests with greater intensity in the caudal relative to rostral subregion. The DRN to ventral tegmental area (VTA) circuit is an additional stress-responsive pathway whereby prodynorphin-expressing neurons release dynorphin at dopaminergic terminals, enabling KOR-dependent suppression of dopamine neuron excitability during acute stressors.
=== DEA classification === Vicoprofen was initially scheduled as a schedule III drug, but was later reclassified to a schedule II drug based on the DEA reclassification of products containing hydrocodone, effective October 2014.
=== Diagnosis and biomarkers === Since a MASLD diagnosis based on a liver biopsy is invasive and makes it difficult to estimate epidemiology, it is a high research priority to find accurate, inexpensive, and noninvasive methods of diagnosing and monitoring MASLD disease and its progression. The search for these biomarkers of MASLD, NAFL, and MASH involves lipidomics, medical imaging, proteomics, blood tests, and scoring systems. According to a review, proton density fat fraction estimation by magnetic resonance imaging (MRI-PDFF) may be considered the most accurate and even gold standard test to quantify hepatic steatosis. They recommend ultrasound-based transient elastography to accurately diagnose both fibrosis and cirrhosis in a routine clinical setting, with more objectivity than ultrasonography but with lower accuracy than magnetic resonance elastography; and plasma cytokeratin 18 (CK18) fragment levels to be a moderately accurate biomarker of steatohepatitis. However, transient elastography can fail for people with pre-hepatic portal hypertension.
Sources: en.wikipedia.org
Arapaima can reach lengths of more than 2 m (6 ft 7 in), in some exceptional cases even exceeding 2.6 m (8 ft 6 in) and over 100 kg (220 lb). The maximum recorded weight for the species is 200 kg (440 lb), while the longest recorded length verified was 3.07 m (10 ft 1 in). Anecdotal reports suggest that specimens as long as 4.57 m (15 ft 0 in) exist, but verification is deemed impossible, and thus considered questionable. As a result of overfishing, arapaima more than 2 m (6 ft 7 in) are seldom found in the wild. The arapaima is torpedo-shaped, with large, blackish-green scales and red markings. It is streamlined and sleek, with its dorsal and anal fins set near its tail. Arapaima scales have a mineralised, hard, outer layer with a corrugated surface under which lie several layers of collagen fibres in a Bouligand-type arrangement. In a structure similar to plywood, the fibres in each successive layer are oriented at large angles to those in the previous layer, increasing toughness. The hard, corrugated surface of the outer layer, and the tough internal collagen layers work synergistically to contribute to their ability to flex and deform while providing strength and protection—a solution that allows the fish to remain mobile while heavily armored. The arapaima has a fundamental dependence on surface air to breathe. In addition to gills, it has a modified and enlarged swim bladder, composed of lung-like tissue, which enables it to extract oxygen from the air.
The confirmation test in most laboratories (and all SAMHSA certified labs) is performed using mass spectrometry, and is precise but expensive. False positive samples from the screening test will almost always be negative on the confirmation test. Samples testing positive during both screening and confirmation tests are reported as positive to the entity that ordered the test. Most laboratories save positive samples for some period of months or years in the event of a disputed result or lawsuit. For workplace drug testing, a positive result is generally not confirmed without a review by a Medical Review Officer who will normally interview the subject of the drug test.
== Research == Much of Limbird's research has explored the activity of G-protein coupled receptors. She has demonstrated how alpha-2 adrenergic receptors are involved in regulation of blood pressure, suppression of pain, sedation and the action of opioid drugs. She has developed techniques for selectively manipulating such receptors. Limbird is the author of Cell Surface Receptors: A Short Course in Theory and Methods (1985, 1996, 2004); co-editor with Joel Hardman of the 9th (1995) and 10th (2001) editions of Goodman and Gilman’s Pharmacological Basis of Therapeutics; editor of Alpha2-Adrenergic Receptors (1988) and co-editor with Stephen Lanier of α2-Adrenergic Receptors. Structure, Function and Therapeutic Implications (1996). Limbird has served on the editorial boards of the Journal of Biological Chemistry, the American Journal of Physiology, and Molecular Pharmacology.
Sources: en.wikipedia.org
Legality depends on the country and the intended use. In many places it is not approved as a medicine and may be sold only as a research chemical. Importation or possession can be restricted, and sports organizations prohibit it.
Anti-doping laboratories typically use LC-MS/MS to detect SR9009 or its metabolites in urine or blood. The exact assay depends on the laboratory and the testing program. Detection can be challenging because the compound may be rapidly metabolized and present at low levels.
Stenabolic is an informal nickname used in online fitness and research-chemical markets, not an official drug name. It likely references reported effects on endurance in rodent studies. The nickname does not imply approval or proven human benefit.
SR9009 is a synthetic research compound that acts on REV-ERB nuclear receptors. It is not approved for human use and is sold only as a research chemical. Its effects have been studied mainly in cells and rodents.