If you have been reading about reference standard 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 2026-05-02. Numbers and descriptions here follow the published literature rather than marketing material.
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.
For long-term storage, SR9009 is typically kept as a solid at low temperature, protected from moisture and light. Desiccated conditions limit hydrolysis, while opaque containers reduce photochemical breakdown. Solutions are less stable than solids and are often stored frozen in aliquots to avoid repeated freeze-thaw cycles. Stability data are not standardized across all suppliers, so users should rely on certificate-of-analysis information when available. Degradation may appear as color change, precipitate, or decreased chromatographic purity.
Laboratory samples of SR9009 are typically handled as research chemicals rather than pharmaceuticals. Suppliers usually state that the material is for research use only and not for human or veterinary administration. Storage recommendations generally call for a freezer at approximately −20 °C, protection from light, and a desiccated environment. The solid is often described as a white to off-white powder. Solubility is commonly reported in organic solvents such as dimethyl sulfoxide and ethanol, with low solubility in water.
Analytical identification and purity assessment often use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Liquid chromatography–tandem mass spectrometry is used to detect and quantify SR9009 in biological matrices, including urine and blood, for anti-doping or pharmacokinetic studies. Nuclear magnetic resonance spectroscopy can confirm molecular structure. Stability depends on form and storage: the solid is generally more stable than solutions, and repeated freeze–thaw cycles may degrade samples. Purity is typically reported as a percentage from a certificate of analysis.
Regulatory treatment of SR9009 varies by country and context. It is not approved as a therapeutic drug by agencies such as the United States Food and Drug Administration or the European Medicines Agency. Sports authorities list it as a prohibited substance; the World Anti-Doping Agency classifies it among hormone and metabolic modulators. Legal status for personal possession or sale differs across jurisdictions, and some countries may restrict it under analog or research chemical laws. Buyers who seek verified material often rely on independent laboratory testing because online product labels may not match contents.
| 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. |
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.
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.
Zinc is an efficient Lewis acid, making it a useful catalytic agent in hydroxylation and other enzymatic reactions. The metal also has a flexible coordination geometry, which allows proteins using it to rapidly shift conformations to perform biological reactions. Two examples of zinc-containing enzymes are carbonic anhydrase and carboxypeptidase, which are vital to the processes of carbon dioxide (CO2) regulation and digestion of proteins, respectively. In vertebrate blood, carbonic anhydrase converts CO2 into bicarbonate and the same enzyme transforms the bicarbonate back into CO2 for exhalation through the lungs. Without this enzyme, this conversion would occur about one million times slower at the normal blood pH of 7 or would require a pH of 10 or more. The non-related β-carbonic anhydrase is required in plants for leaf formation, the synthesis of indole acetic acid (auxin) and alcoholic fermentation. Carboxypeptidase cleaves peptide linkages during digestion of proteins. A coordinate covalent bond is formed between the terminal peptide and a C=O group attached to zinc, which gives the carbon a positive charge. This helps to create a hydrophobic pocket on the enzyme near the zinc, which attracts the non-polar part of the protein being digested.
S3: The S3 pocket is located on the rim of the S1 pocket and is flat and exposed to the solvent. This pocket is not as important as S1 and S4. S4: The S4 pocket is hydrophobic in nature and the floor of the pocket is formed by Trp-215 residue. The residues Phe-174 and Tyr-99 of FXa join Trp-215 to form an aromatic box that is able to bind aliphatic, aromatic and positively charged fragments. Because of the binding to positively charged entities, it can be described as a cation hole.
is not known. The other example, adenosine monophosphate is shown to illustrate the fact that a third species may, in principle, be involved. In fact the concentration of (AMP)H2+3 is negligible at the isoelectric point in this case. If the pI is greater than the pH, the molecule will have a positive charge.
Sources: en.wikipedia.org
=== Autoimmune === Lichen planus: A chronic inflammatory disease with different forms of oral presentations. The most classic appearance of lichen planus is the presence of white streaks in inner cheek, tongue, and gum. Desquamative gingivitis can be seen in patients with lichen planus. Biopsy is done for definitive diagnosis of lichen planus. Graft-versus-host disease: An autoimmune disease developed following bone marrow transplant in which its oral presentation is similar to lichen planus. Pemphigus vulgaris: An autoimmune chronic disease with clinical presentation of formation of superficial and large blisters which then burst into ulcers on the skin or mucous membrane. Mucous-membrane pemphigoid: Autoimmune disease which affects only mucous membranes with clinical presentation of hard and rigid blisters which then rupture eventually into deep ulcers. Cutaneous lupus erythematosus: These present as oral discoid lesions which may be present on the inner cheek and behind the lips. White papules may also be present.
Microbes have been engineered to produce proteins similar or even "bioidentical" to whey. Various companies offer microbe-produced whey and cheese; however, none of these companies stipulate the protein composition of their products, but they do contain some of the genes needed to make whey proteins.
Paleolithic hunting and gathering people ate varying proportions of vegetables (including tubers and roots), fruit, seeds (including nuts and wild grass seeds) and insects, meat, fish, and shellfish. However, there is little direct evidence of the relative proportions of plant and animal foods. Although the term "paleolithic diet", without references to a specific timeframe or locale, is sometimes used with an implication that most humans shared a certain diet during the entire era, that is not entirely accurate. The Paleolithic was an extended period of time, during which multiple technological advances were made, many of which had impact on human dietary structure. For example, humans probably did not possess the control of fire until the Middle Paleolithic, or tools necessary to engage in extensive fishing. On the other hand, both these technologies are generally agreed to have been widely available to humans by the end of the Paleolithic (consequently, allowing humans in some regions of the planet to rely heavily on fishing and hunting). In addition, the Paleolithic involved a substantial geographical expansion of human populations. During the Lower Paleolithic, ancestors of modern humans are thought to have been constrained to Africa east of the Great Rift Valley. During the Middle and Upper Paleolithic, humans greatly expanded their area of settlement, reaching ecosystems as diverse as New Guinea and Alaska, and adapting their diets to whatever local resources were available.
Sources: en.wikipedia.org
44 (9): 1829. doi:10.1016/0009-2509(89)85125-5. M. König (2008). Herstellung und Charakterisierung nanoporöser Monolithe auf Basis poröser Gläser mit optimierter geometrischer Form zur Anwendung in der Sensortechnik. Diplomarbeit, Halle.
When a model of replicating molecules was created, it was found that, for effective storage of information, macromolecules on prebiotic Earth could not exceed a certain threshold length. This problem is known as the error threshold problem. It arises because replication is an imperfect process, and during each replication event, there is a risk of incorporating errors into a new sequence, leading to the creation of a quasispecies. In a system that is deprived of high-fidelity replicases and error-correction mechanisms, mutations occur with a high probability. As a consequence, the information stored in a sequence can be lost due to the rapid accumulation of errors, a so-called error catastrophe. Moreover, it was shown that the genome size of any organism is roughly equal to the inverse of mutation rate per site per replication. Therefore, a high mutation rate imposes a serious limitation on the length of the genome. To overcome this problem, a more specialized replication machinery that is able to copy genetic information with higher fidelity is needed. Manfred Eigen suggested that proteins are necessary to accomplish this task. However, to encode a system as complex as a protein, longer nucleotide sequences are needed, which increases the probability of a mutation even more and requires even more complex replication machinery. John Maynard Smith and Eörs Szathmáry named this vicious circle Eigen's Paradox.
==== Size-exclusion chromatography (FPLC) ==== Due to the apparent size differences by the degree of PEGylation of the protein, size-exclusion chromatography (fast protein liquid chromatography or FPLC) can be used. There is a negative correlation between molecular weight and the retention time of the PEGylated protein in the chromatogram; larger protein, or more PEGylated protein elutes first, and smaller protein, or intact protein the latest.
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.
Legality depends on the country and the intended use. In many places it is sold as a research chemical, but sports and medicine regulations restrict it.