If you have been reading about anti-doping 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.
Updated 2026-01-22. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
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.
==== Recombinant DNA ==== Biotechnology in the modern sense of genetic engineering began in the 1970s, with the invention of recombinant DNA techniques. Restriction enzymes were discovered and characterized in the late 1960s, following on the heels of the isolation, then duplication, then synthesis of viral genes. Beginning with the lab of Paul Berg in 1972 (aided by EcoRI from Herbert Boyer's lab, building on work with ligase by Arthur Kornberg's lab), molecular biologists put these pieces together to produce the first transgenic organisms. Soon after, others began using plasmid vectors and adding genes for antibiotic resistance, greatly increasing the reach of the recombinant techniques. Wary of the potential dangers (particularly the possibility of a prolific bacteria with a viral cancer-causing gene), the scientific community as well as a wide range of scientific outsiders reacted to these developments with both enthusiasm and fearful restraint. Prominent molecular biologists led by Berg suggested a temporary moratorium on recombinant DNA research until the dangers could be assessed and policies could be created. This moratorium was largely respected, until the participants in the 1975 Asilomar Conference on Recombinant DNA created policy recommendations and concluded that the technology could be used safely. Following Asilomar, new genetic engineering techniques and applications developed rapidly. DNA sequencing methods improved greatly (pioneered by Frederick Sanger and Walter Gilbert), as did oligonucleotide synthesis and transfection techniques.
=== Insulin, large neutral amino acids, and tryptophan === When foods with a high glycemic index are consumed, the carbohydrates in the food are more easily digested than low glycemic index foods. Hence, more glucose is available for absorption. It should not be misunderstood that glucose is absorbed more rapidly because, once formed, glucose is absorbed at the same rate. It is only available in higher amounts due to the ease of digestion of high glycemic index foods. In individuals with normal carbohydrate metabolism, insulin levels rise concordantly to drive glucose into the body's tissues and maintain blood glucose levels in the normal range. Insulin stimulates the uptake of valine, leucine, and isoleucine into skeletal muscle, but not uptake of tryptophan. This lowers the ratio of these branched-chain amino acids in the bloodstream relative to tryptophan (an aromatic amino acid), making tryptophan preferentially available to the large neutral amino acid transporter at the blood–brain barrier. Uptake of tryptophan by the brain thus increases. In the brain, tryptophan is converted to serotonin, which is then converted to melatonin. Increased brain serotonin and melatonin levels result in sleepiness.
==== Tag position ==== Most commonly, a polyhistidine tag is fused at the N-terminus or C-terminus of a protein and is attached via a short flexible linker, which may contain a protease cleavage site. Less commonly, tags can be added at both the N- and C-termini or inserted at an intermediate part of a protein, such as within an exposed loop. The choice of tag position depends on the properties of each protein and the chosen purification strategy; it may be necessary to test multiple constructs with the tag at different positions. Although polyhistidine tags are considered to typically not alter the properties of a protein, it has been demonstrated that addition of the tag can cause unwanted effects, such as influencing the protein's oligomeric state.
A hormone can perform functions over a larger spatial and temporal scale than can a neurotransmitter, which often acts in micrometer-scale distances. Hormonal signals can travel virtually anywhere in the circulatory system, whereas neural signals are restricted to pre-existing nerve tracts. Assuming the travel distance is equivalent, neural signals can be transmitted much more quickly (in the range of milliseconds) than can hormonal signals (in the range of seconds, minutes, or hours). Neural signals can be sent at speeds up to 100 meters per second. Neural signalling is an all-or-nothing (digital) action, whereas hormonal signalling is an action that can be continuously variable as it is dependent upon hormone concentration. Neurohormones are a type of hormone that share a commonality with neurotransmitters. They are produced by endocrine cells that receive input from neurons, or neuroendocrine cells. Both classic hormones and neurohormones are secreted by endocrine tissue; however, neurohormones are the result of a combination between endocrine reflexes and neural reflexes, creating a neuroendocrine pathway. While endocrine pathways produce chemical signals in the form of hormones, the neuroendocrine pathway involves the electrical signals of neurons. In this pathway, the result of the electrical signal produced by a neuron is the release of a chemical, which is the neurohormone. Finally, like a classic hormone, the neurohormone is released into the bloodstream to reach its target.
Sources: en.wikipedia.org
Leonidas Zervas (Greek: Λεωνίδας Ζέρβας, pronounced [leoˈniðas ˈzervas]; 21 May 1902 – 10 July 1980) was a Greek organic chemist who made seminal contributions in peptide chemical synthesis. Together with his mentor Max Bergmann they laid the foundations for the field in 1932 with their major discovery, the Bergmann-Zervas carboxybenzoxy oligopeptide synthesis which remained unsurpassed in utility for the next two decades. The carboxybenzyl protecting group he discovered is often abbreviated Z in his honour. Throughout his life Zervas also served in many important posts, including President of the Academy of Athens or briefly Minister of Industry of Greece. He received numerous awards and honours during his life and posthumously, such as Foreign Member of the USSR Academy of Sciences or the first Max Bergmann golden medal.
Japan In Japan, dihydrocodeine is available without a prescription; used in cough medicines such as New Bron Solution-ACE. Dihydrocodeine is used as an antitussive in many products as a Dextromethorphan alternative. Medicines in Japan which contain dihydrocodeine are coupled with caffeine to offset the sedative effects and discourage recreational use. Cough medicines containing dihydrocodeine are controlled similarly to dextromethorphan in the United States, in that its sale is strictly limited by purchase quantity and is restricted to persons 20 and older for purchase. United Kingdom In the United Kingdom, dihydrocodeine is a Class B drug; but, it is available over-the-counter in small amounts (less than 8 mg), when combined with paracetamol (see co-dydramol). Dihydrocodeine is listed in Schedule 5 of the Misuse of Drugs Regulations 2001 whereby it is exempt from prohibition on possession provided that it is in the form of a single preparation not being designed for injection and less than 100 mg (calculated as free base) or with a total concentration less than 2.5% (calculated as free base). Illegal possession of dihydrocodeine can result in up to 5 years in prison or an unlimited fine. United States In the US, pure dihydrocodeine is a DEA Schedule II substance, although preparations containing small amounts of dihydrocodeine can also be classified as Schedule III or Schedule V, depending on the concentration of dihydrocodeine relative to other active constituents, such as paracetamol (acetaminophen). The DEA's ACSCN for dihydrocodeine free base and all salts is 9120.
Lisdexamphetamine is an inactive prodrug that is converted in the body to dextroamphetamine, a pharmacologically active compound that is responsible for the drug's activity. After oral ingestion, lisdexamphetamine is broken down by enzymes in red blood cells to form L-lysine, a naturally occurring essential amino acid, and dextroamphetamine. The half-life of this conversion is roughly 1 hour. The conversion of lisdexamphetamine to dextroamphetamine is not affected by gastrointestinal pH and is unlikely to be affected by alterations in normal gastrointestinal transit times. Studies show a linear relationship between peak plasma concentration of dextroamphetamine and lisdexamphetamine dose up to lisdexamphetamine doses of 250 mg. The optical isomers of amphetamine, i.e., dextroamphetamine and levoamphetamine, are TAAR1 agonists and vesicular monoamine transporter 2 inhibitors that can enter monoamine neurons; this allows them to release monoamine neurotransmitters (dopamine, norepinephrine, and serotonin, among others) from their storage sites in the presynaptic neuron, as well as prevent the reuptake of these neurotransmitters from the synaptic cleft. Lisdexamphetamine was developed to provide a long-duration effect that is consistent throughout the day, with reduced potential for abuse. The attachment of the amino acid lysine slows down the relative amount of dextroamphetamine available in the bloodstream.
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.