circadian rhythm 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.
Updated 2025-11-02. 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.
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.
| 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 |
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.
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 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.
SR9009 is a synthetic small molecule developed as a REV-ERB agonist. It binds to REV-ERBα and REV-ERBβ, nuclear receptors that help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, the compound alters lipid and glucose handling and influences skeletal muscle oxidative capacity. Its exact effects in humans remain largely uncharacterized because controlled clinical trials have not been reported. The molecule is frequently described in preclinical literature as a metabolic modulator.
Research interest in SR9009 grew from studies showing improved running endurance in mice after short treatment periods. Those experiments linked the compound to increased mitochondrial content and fatty acid oxidation in muscle, but the findings come from animal models and specific dosing schedules. Independent replication has been limited, and the pathways connecting REV-ERB activation to exercise performance are still being mapped. Whether similar responses occur in humans is an open question.
=== Factors increasing cortisol levels === Viral infections increase cortisol levels through activation of the HPA axis by cytokines. Intense (high VO2 max) or prolonged aerobic exercise transiently increases cortisol levels to increase gluconeogenesis and maintain blood glucose; however, cortisol declines to normal levels after eating (i.e., restoring a neutral energy balance). Severe trauma or stressful events can elevate cortisol levels in the blood for prolonged periods. Low-carbohydrate diets cause a short-term increase in resting cortisol (≈3 weeks), and increase the cortisol response to aerobic exercise in the short- and long-term. Increase in the concentration of ghrelin, the hunger stimulating hormone, increases levels of cortisol.
== Applications == When processed industrially, 1,000 kg of bones yield 300 kg of ossein, which can be rapidly degraded and partially denatured by the prolonged action of slightly acidic boiling water, yielding gelatin. The product is specifically known as ossein gelatin in contrast to skin gelatin, which is generated from animal hides. Depending on the method of extraction, there are various types of ossein gelatin (acid ossein gelatin, limed ossein gelatin, etc.). Another prominent use of ossein is the production of bone glue, whose yield is 16-20% of the mass of dry bone. Bones that are unsuitable for ossein production can be carbonized to generate bone char, used to filter water among other uses.
A significant player in the process is transforming growth factor (TGFβ). This protein appears to be overproduced, and the fibroblast (possibly in response to other stimuli) also overexpresses the receptor for this mediator. An intracellular pathway (consisting of SMAD2/SMAD3, SMAD4, and the inhibitor SMAD7) is responsible for the secondary messenger system that induces transcription of the proteins and enzymes responsible for collagen deposition. Sp1 is a transcription factor most closely studied in this context. Apart from TGFβ, connective tissue growth factor (CTGF) has a possible role. Indeed, a common CTGF gene polymorphism is present at an increased level in systemic sclerosis. Damage to endothelium is an early abnormality in the development of scleroderma, and this, too, seems to be due to collagen accumulation by fibroblasts, although direct alterations by cytokines, platelet adhesion, and a type II hypersensitivity reaction similarly have been implicated. Increased endothelin and decreased vasodilation have been documented. Jimenez and Derk describe three theories about the development of scleroderma:
=== EC 7.3 Catalysing the translocation of inorganic anions === This subclass contains translocases that transfer inorganic cations anions. Subclasses are based on the reaction processes that provide the driving force for the translocation. At present only one subclass is represented: EC 7.3.2 Translocation of inorganic anions linked to the hydrolysis of a nucleoside triphosphate.
Sources: en.wikipedia.org
This phenomenon, where molecule Y affects the binding of molecule X to a transport molecule Z, is called a heterotropic allosteric effect. Hemoglobin in organisms at high altitudes has also adapted such that it has less of an affinity for 2,3-BPG and so the protein will be shifted more towards its R state. In its R state, hemoglobin will bind oxygen more readily, thus allowing organisms to perform the necessary metabolic processes when oxygen is present at low partial pressures. Animals other than humans use different molecules to bind to hemoglobin and change its O2 affinity under unfavorable conditions. Fish use both ATP and GTP. These bind to a phosphate "pocket" on the fish hemoglobin molecule, which stabilizes the tense state and therefore decreases oxygen affinity. GTP reduces hemoglobin oxygen affinity much more than ATP, which is thought to be due to an extra hydrogen bond formed that further stabilizes the tense state. Under hypoxic conditions, the concentration of both ATP and GTP is reduced in fish red blood cells to increase oxygen affinity. A variant hemoglobin, called fetal hemoglobin (HbF, α2γ2), is found in the developing fetus, and binds oxygen with greater affinity than adult hemoglobin. This means that the oxygen binding curve for fetal hemoglobin is left-shifted (i.e., a higher percentage of hemoglobin has oxygen bound to it at lower oxygen tension), in comparison to that of adult hemoglobin. As a result, fetal blood in the placenta is able to take oxygen from maternal blood. Hemoglobin also carries nitric oxide (NO) in the globin part of the molecule.
=== Community giving === The Day-End Dough-Nation program provides unsold bread and baked goods to local area hunger relief agencies and charities. Panera Bread bakery-cafes donate $100 million worth of unsold bread and baked goods annually to local organizations. Panera also supports events held by non-profit organizations serving those in need by donating a certificate or fresh bakery products.
== Therapeutic use == Recent studies have shown that SK channels do not only regulate afterhyperpolarization, they also have an effect on synaptic plasticity. This is the activity-dependent adaptation of the strength of synaptic transmission. Synaptic plasticity is an important mechanism underlying learning and memory processes. Apamin is expected to influence these processes by inhibiting SK channels. It has been shown that apamin enhances learning and memory in rats and mice. This may provide a basis for the use of apamin as a treatment for memory disorders and cognitive dysfunction. However, due to the risk of toxic effects, the therapeutic window is very narrow. SK channel blockers may have a therapeutic effect on Parkinson's disease. Dopamine, which is depleted in this disease, will be released from midbrain dopaminergic neurons when these SK channels are inhibited. SK channels have also been proposed as targets for the treatment of epilepsy, emotional disorders and schizophrenia.
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 activates the REV-ERBα and REV-ERBβ nuclear receptors. It is not an approved drug and has no established human therapeutic use. Most published biological data come from cell and rodent studies.