If you have been reading about anti-doping testing 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 2025-11-21. Where a claim depends on a specific study, the study is described rather than over-claimed.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is not an approved medicine and has no established human therapeutic use. The compound appears in scientific literature as a tool for probing circadian and metabolic regulation. Online sellers often label it as a research chemical, sometimes using the nickname Stenabolic. Its chemical identity is distinct from selective androgen receptor modulators, stimulants, and peroxisome proliferator-activated receptor delta agonists. Researchers use it mainly in cell and animal experiments.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C20H24ClN3O4S | Derived from published structure. |
| Molecular weight | 437.94 g/mol | Calculated value. |
| Appearance | White to off-white solid | Typical for purified research samples. |
| Solubility | DMSO, ethanol; low in water | Class: poorly water-soluble. |
| Typical storage | -20 °C, desiccated, protected from light | Limits degradation. |
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.
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.
Scientific discussion of SR9009 often separates animal evidence from human anecdote. Rodent studies provide controlled data on endurance, metabolism, and gene expression, but they use specific strains, doses, and treatment durations. Human reports are mostly uncontrolled and cannot establish cause and effect. Open questions include oral bioavailability, tissue distribution, metabolic stability, and long-term effects. Review articles generally call for more rigorous pharmacokinetic and safety research before any clinical use could be considered.
4 RSeOH → 2 RSe(O)SeR + 2 H2O Even the very bulky 2,4,6-tri-tert-butylbenzeneselenenic acid disproportionates readily. Stable selenenic acids have been synthesized by burying the SeOH functional group within the cavity of a p-tert-butyl[calix[6]arene macrocycle]. In BmtSeOH (pictured), the Se-O bond length was found to be 1.808 Å while the O-Se-C angle was 96.90°. The compound was made by oxidation of BmtSeH; further oxidation gave BmtSeO2H. The Se-O absorbs in the IR spectrum at 680–700 cm−1. Selenenic acids are believed to be transient intermediates in a number of redox reactions involving organoselenium compounds. One notable example is the syn-elimination of selenoxides. Selenenic acids are also transient intermediates in the reduction of seleninic acids as well as the oxidation of diselenides. The reasoning for postulating selenenic acids as reactive intermediates is based in part on analogy with their more extensively studied sulfenic acid analogs.
In addition to ribosome dimerization, the joining of the two ribosomal subunits can be blocked by RsfS (formerly called RsfA or YbeB). RsfS binds to L14, a protein of the large ribosomal subunit, and thereby blocks joining of the small subunit to form a functional 70S ribosome, slowing down or blocking translation entirely. RsfS proteins are found in almost all eubacteria (but not archaea) and homologs are present in mitochondria and chloroplasts (where they are called MALSU1 and iojap, respectively). However, it is not known yet how the expression or activity of RsfS is regulated. Another ribosome-dissociation factor in Escherichia coli is HflX, previously a GTPase of unknown function. Zhang et al. (2015) showed that HflX is a heat shock–induced ribosome-splitting factor capable of dissociating vacant as well as mRNA-associated ribosomes. The N-terminal effector domain of HflX binds to the peptidyl transferase center in a strikingly similar manner as that of the class I release factors and induces dramatic conformational changes in central intersubunit bridges, thus promoting subunit dissociation. Accordingly, loss of HflX results in an increase in stalled ribosomes upon heat shock and possibly other stress conditions.
Repotrectinib, sold under the brand name Augtyro, is an anti-cancer medication used for the treatment of non-small cell lung cancer. It is taken by mouth. Repotrectinib is an inhibitor of proto-oncogene tyrosine-protein kinase ROS1 (ROS1) and of the tropomyosin receptor tyrosine kinases (TRKs) TRKA, TRKB, and TRKC. The most common adverse reactions include dizziness, dysgeusia, peripheral neuropathy, constipation, dyspnea, ataxia, fatigue, cognitive disorders, and muscular weakness. Repotrectinib was approved for medical use in the United States in November 2023, and in the European Union in January 2025.
Sources: en.wikipedia.org
== Types of reactions == An exergonic reaction is a spontaneous chemical reaction that releases energy. It is thermodynamically favored, indexed by a negative value of ΔG (Gibbs free energy). Over the course of a reaction, energy needs to be put in, and this activation energy drives the reactants from a stable state to a highly energetically unstable transition state to a more stable state that is lower in energy (see: reaction coordinate). The reactants are usually complex molecules that are broken into simpler products. The entire reaction is usually catabolic. The release of energy (called Gibbs free energy) is negative (i.e. −ΔG) because energy is released from the reactants to the products. An endergonic reaction is an anabolic chemical reaction that consumes energy. It is the opposite of an exergonic reaction. It has a positive ΔG because it takes more energy to break the bonds of the reactant than the energy of the products offer, i.e. the products have weaker bonds than the reactants. Thus, endergonic reactions are thermodynamically unfavorable. Additionally, endergonic reactions are usually anabolic. The free energy (ΔG) gained or lost in a reaction can be calculated as follows: ΔG = ΔH − TΔS where ∆G = Gibbs free energy, ∆H = enthalpy, T = temperature (in kelvins), and ∆S = entropy.
=== Exercise === It is recommended that hypermobile individuals remain fit, to prevent pain and fatigue. Regular exercise and exercise that is supervised by a physician and physical therapist can reduce symptoms because strong muscles increase dynamic joint stability. Low-impact exercise such as closed kinetic chain exercises are usually recommended as they are less likely to cause injury when compared to high-impact exercise or contact sports. Hydrotherapy can also be a beneficial medium for muscle training. Some isometric exercises can also be beneficial. Coordination may be improved through balance exercises. High impact sports are not recommended.
== History == Twinlab was founded by David and Jean Blechman in 1968 and run by them and their sons – Neil, Brian, Ross, Steve and Dean. Using experience gained from over 20 years as a pharmaceutical salesman, David Blechman named the company for his two sets of twins and started marketing a liquid protein supplement from their family garage. Sales of Twinlab's only product skyrocketed in the 1970s, in part from the success of a 1976 book entitled The Last Chance Diet — When Everything Else Has Failed: Dr. Linn's Protein-Sparing Fast Program. Dr. Robert Linn was a Pennsylvania osteopath, who had begun prescribing for his overweight patients a program of fasting and four- to six-ounce daily doses of liquid protein. His book sold extremely well, and Dr. Linn's diet became the latest weight-loss fad diet. This led to increased sales for Twinlab's liquid protein. As with many fad diets, the fasting/liquid protein craze came to a halt when in late 1976 and early 1977 there were reports of the deaths of 58 people who had followed Linn's diet. Following a U.S. Food and Drug Administration (FDA) investigation the associated coverage of the popular diet and its potential side effects by Newsweek, Parents' Magazine, and Science Digest, the liquid protein market bottomed out, and Twinlab's revenues declined sharply forcing the company to cut nearly all of its 150-person workforce. In the 1980s Twinlab branched out formulating new vitamin and nutritional supplements and purchased a publishing company called Advanced Research Press, Inc.
The BSE SENSEX (also known as the S&P Bombay Stock Exchange Sensitive Index or simply SENSEX) is an Indian free-float market-weighted stock market index of 30 well-established and financially sound companies listed on the Bombay Stock Exchange. The 30 constituent companies which are some of the largest and most actively traded stocks, are representative of various industrial sectors of the Indian economy. Published since 1 January 1986, the S&P BSE SENSEX is regarded as the pulse of the domestic stock markets in India. The base value of the SENSEX was taken as 100 on 1 April 1979 and its base year as 1978–79. On 25 July 2001, BSE launched DOLLEX-, a dollar-linked version of the SENSEX.
Sources: en.wikipedia.org
SR9009 is a synthetic REV-ERB agonist used in laboratory research. It is not an approved drug, and its effects in humans are not well characterized. It is often sold as a research chemical under the name Stenabolic.
No. SR9009 targets the nuclear receptors REV-ERBα and REV-ERBβ, not the androgen receptor. This mechanism differs from selective androgen receptor modulators and from exercise mimetics that act on PPARδ.
Published evidence is mainly preclinical, using cell cultures and animal models. Controlled human trials are not well documented in the public literature. Claims about human performance or health effects therefore remain unsupported by robust clinical data.
Its legal status depends on the country and intended use. It is not an approved medicine in major jurisdictions. In sport, it is prohibited by anti-doping rules.