If you have been reading about circadian rhythm 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 2025-09-30. 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.
REV-ERB proteins typically suppress gene expression by recruiting corepressor complexes to DNA response elements. SR9009 binds these receptors and strengthens that repressive action in cell-based assays. Studies in rodents have reported changes in lipid handling, mitochondrial function, and exercise capacity after treatment. Such findings are often cited as evidence for metabolic effects, but species differences and limited pharmacokinetic data make direct translation to humans uncertain. Researchers continue to examine which effects are robust and which depend on specific experimental conditions.
SR9009 is frequently discussed alongside other REV-ERB ligands, including synthetic agonists and natural heme-related molecules. Its selectivity for REV-ERB over related nuclear receptors has been measured in binding and reporter assays, though off-target activity at higher concentrations is possible. The compound is prohibited in sport by the World Anti-Doping Agency, and it is not approved for any medical use in major jurisdictions. Products sold online may be labeled as research chemicals, and their identity and purity are not guaranteed by regulatory review.
SR9009 is a synthetic small molecule that acts on the nuclear receptors REV-ERBα and REV-ERBβ. These receptors are part of the circadian clock machinery and normally repress transcription of certain target genes. In laboratory research, SR9009 is used as a chemical tool to study how REV-ERB activity influences metabolism, inflammation, and daily biological rhythms. The compound is not an approved medicine, and its effects in humans remain largely uncharacterized. It is often described as an investigational agent rather than a therapeutic product.
| 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 an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. These receptors help regulate circadian rhythms, lipid metabolism, and inflammatory gene expression. In cell and animal experiments, SR9009 alters transcription of clock-controlled genes and metabolic pathways. The compound is not a hormone and does not resemble classical steroid structures. Its activity depends on binding to the ligand-binding domain of REV-ERB, where it can modify corepressor recruitment.
Research interest in SR9009 grew from studies of circadian biology and metabolic disease. Preclinical reports describe effects on exercise capacity, muscle metabolism, and blood lipid levels in rodents, but these findings come from controlled laboratory settings. The compound has low oral bioavailability in animals, which limits systemic exposure after swallowing. Investigators often use injected routes in experiments to achieve measurable plasma concentrations. Human clinical data are sparse, no approved therapeutic product exists, and whether animal effects translate to humans remains an open question.
In laboratory settings, SR9009 is commonly identified by its molecular structure and its interaction with REV-ERB receptors. Vendors may list it under synonyms such as Stenabolic or REV-ERB agonist, but those names do not define purity or identity. Analytical confirmation typically uses high-performance liquid chromatography with ultraviolet detection or liquid chromatography–mass spectrometry. A reference standard is needed to compare retention time and mass spectrum, because the compound can be confused with related research chemicals.
Handling practices for SR9009 focus on minimizing degradation and contamination. The solid is generally stored desiccated at or below -20 °C, protected from light and moisture. Stock solutions are often prepared in dimethyl sulfoxide or ethanol, then aliquoted to avoid repeated freeze–thaw cycles. Aqueous solubility is low, so formulations for animal studies may require cosolvents or suspending agents. Personnel should follow institutional chemical safety procedures, because toxicological data for humans are incomplete.
Regulatory status varies by country and intended use. Major drug agencies have not granted marketing authorization for SR9009 as a medicine, and it is not listed as a controlled substance in many jurisdictions. It is often sold as a research chemical, a category that may fall outside pharmaceutical manufacturing rules. Buyers should verify local laws and supplier documentation, including certificates of analysis. The lack of standardized quality controls raises concerns about identity, purity, and actual content in products marketed online.
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.
=== Danger of confusion with paregoric === In the United States, opium tincture contains 10 mg per mL of anhydrous morphine. By contrast, opium tincture's weaker cousin, paregoric, also confusingly known as "camphorated tincture of opium", is 1/25th the strength of opium tincture, containing only 0.4 mg of morphine per mL. A 25-fold morphine overdose may occur if opium tincture is used where paregoric is indicated. Opium tincture is almost always dosed in drops, or fractions of a mL, or less commonly, in minims, while paregoric is dosed in teaspoons or tablespoons. Thus, an order for opium tincture containing directions in teaspoons is almost certainly in error. To avoid this potentially fatal outcome, the term "camphorated tincture of opium" is avoided in place of paregoric since the former can easily be mistaken for opium tincture. In 2004, the FDA issued a "Patient Safety" news bulletin stating that "To help resolve the confusion [between opium tincture and paregoric], FDA will be working with the manufacturers of these two drugs to clarify the labeling on the containers and in the package inserts." Indeed, in 2005, labels for opium tincture began to include the concentration of morphine (10 mg/mL) in large text beneath the words "Opium Tincture".
=== February === 3 February – Prime Minister Keir Starmer rejects an allegation that he broke COVID-19 regulations by having a voice coach present at a press conference where he responded to a Brexit deal negotiated by Boris Johnson. For the first time, Reform UK have led an opinion poll, after coming top with 25% in a YouGov poll for Sky News. Labour are second on 24%, with the Conservatives on 21%. Northern Ireland's Economy Minister, Conor Murphy steps down from the post and announces he will leave Stormont after being elected to the Irish Seanad. Caoimhe Archibald is appointed to replace him as Economy Minister. 4 February – BBC News reports that Jack Lopresti, the former Conservative MP for Filton and Bradley Stoke who lost the seat at the last general election has joined the Ukrainian military. Welsh Conservatives leader Darren Millar and his colleague Russell George miss a Senedd vote on the Eluned Morgan government's budget for 2025–26 because they have travelled to the United States for the annual National Prayer Breakfast. 5 February – Deputy Prime Minister Angela Rayner confirms that local elections in East Sussex, West Sussex, Essex, Thurrock, Hampshire, the Isle of Wight, Norfolk, Suffolk and Surrey will be delayed for a year to allow major local government reorganisations to take place. Four of the seven MPs suspended from the Labour Party for voting against the child benefit cap are readmitted to the party; they are Richard Burgon, Ian Byrne, Imran Hussain and Rebecca Long-Bailey.
=== Exceptions === Some jellyfish species, including Turritopsis dohrnii, Laodicea undulata, and Aurelia sp.1, are able to revert to the polyp stage even after reproducing (so-called reversible life cycle), rather than dying as in other jellyfish. Consequently, these species are considered biologically immortal and have no maximum lifespan. There may be no natural limit to the hydra's life span, but it is not yet clear how to estimate the age of a specimen. Flatworms, or Platyhelminthes, are known to be "almost immortal" as they have a great regeneration capacity, continuous growth, and binary fission type cellular division. Lobsters are sometimes said to be biologically immortal because they do not seem to slow down, weaken, or lose fertility with age. However, due to the energy needed for moulting, they cannot live indefinitely.
=== Tastes Like America === In 2018, CKE resumed producing separate campaigns for their Hardee's and Carl's Jr. brands. For Hardee's, it started the Tastes Like America campaign with music by Big Wet. For this campaign, Hardee's restored its 1976 logo, now in white; however, the Happy Star still appears, replacing the A in "Tastes". The previous logo will also continue to be used as well.
Sources: en.wikipedia.org
Members of this family are found in birds, fish, reptiles and amphibians (mesotocin, isotocin, valitocin, glumitocin, aspargtocin, vasotocin, seritocin, asvatocin, phasvatocin), in worms (annetocin, nematocin), octopuses (cephalotocin, octopressin), insects (locupressin, inotocin) and in molluscs (conopressins G and S). Animals that lack a hormone from this family include fruit flies, and at least some mosquitos, silkworms, and honeybees.
Hahn spent February to June 1933 in the United States and Canada as a visiting professor at Cornell University. He gave an interview to the Toronto Star Weekly in which he painted a flattering portrait of Adolf Hitler: I am not a Nazi. But Hitler is the hope, the powerful hope, of German youth... At least 20 million people revere him. He began as a nobody, and you see what he has become in ten years.... In any case for the youth, for the nation of the future, Hitler is a hero, a Führer, a saint... In his daily life he is almost a saint. No alcohol, not even tobacco, no meat, no women. In a word: Hitler is an unequivocal Christ. The April 1933 Law for the Restoration of the Professional Civil Service banned Jews and communists from academia. Meitner was exempt from its impact because she was an Austrian rather than a German citizen. Haber was likewise exempt as a veteran of World War I, but chose to resign his directorship of the Kaiser Wilhelm Institute of Physical Chemistry and Electrochemistry in protest on 30 April 1933. The directors of the other Kaiser Wilhelm Institutes, even the Jewish ones, complied with the new law, which applied to the KWS as a whole and those Kaiser Wilhelm institutes with more than 50% state support, which exempted the KWI for Chemistry. Hahn therefore did not have to fire any of his own full-time staff, but as the interim director of Haber's institute, he dismissed a quarter of its staff, including three department heads. Gerhart Jander was appointed the new director of Haber's old institute, and reoriented it towards chemical warfare research.
Pitting also may be caused by a variety of systemic diseases, including reactive arthritis and other connective tissue disorders, sarcoidosis, pemphigus, alopecia areata, and incontinentia pigmenti. Because pitting is caused by defective layering of the superficial nail plate by the proximal nail matrix, any localized dermatitis (e.g., atopic dermatitis or chemical dermatitis) that disrupts orderly growth in that area also can cause pitting.
Sources: en.wikipedia.org
==== Prontosan ==== Prontosan (B Braun) Wound Irrigation Solution and Prontosan Wound Gel are proprietary preparations of PHMB with betaine, an alkaloid surfactant. Surfactants lower the surface tension of the fluid medium making it easier to infiltrate wound coatings, debris and bacteria. Both the wound irrigation solution and the wound gel are colorless cleansing agents that are indicated for use in acute and chronic wounds. They also have the potential to be used in conjunction with a range of dressing materials which include occlusive dressings. In vitro studies on clinical isolates of E. coli and S. epidermidis have demonstrated the anti-biofilm efficacy of PHMB. The activity of five biocides at various concentrations was recorded following exposure to the isolates. The biocides found to be most active towards planktonic (free floating) cells were PHMB and peracetic acid. A corresponding level of activity towards biofilm phenotype bacteria was also found with the two agents. Prontosan's activity on MRSA biofilms has been investigated using an in vivo porcine wound model. Prontosan activity was compared with Ringer's solution, saline, and untreated control. A comparative reduction in MRSA at 48 and 72 hours in the Prontosan-treated group was found to be statistically significant compared to the other groups (p-value <0.05). The study results indicated that extended irrigation with Prontosan may provide additional reduction in wound bioburden as the largest reduction of MRSA was found from 48 to 72 hours.
Chitin was probably present in the exoskeletons of Cambrian arthropods such as trilobites. The oldest preserved (intact) chitin samples thus far reported are dated to the Oligocene, about 25 million years ago, from specimens encased in amber where the chitin has not completely degraded.
Followers of Jainism practice a strict lacto-vegetarian diet deeply rooted in the fundamental ethical principle of nonviolence (ahimsa). Unlike many other dietary frameworks, Jain vegetarianism operates on a rigorous biological taxonomy that categorizes lifeforms by their number of sense organs, ranging from one-sensed organisms (ekendriya jiva, such as plants and water) to five-sensed beings (panchendriya jiva, such as mammals and humans). The overarching dietary goal is to completely eliminate violence against higher-sensed beings (meat, fish, and eggs) while strictly minimizing harm to single-sensed organisms and microscopic life. To achieve this, the diet extends significantly beyond standard vegetarianism. Jains strictly avoid root and underground vegetables—such as potatoes, onions, and garlic—because harvesting them requires uprooting and killing the entire plant, and disrupts massive clusters of microscopic lifeforms (nigoda) that thrive in the soil and root systems. The consumption of honey is absolutely forbidden due to the violent disruption of the hive during extraction and because its viscous nature makes it a breeding ground for microorganisms. Similarly, fungi (mushrooms) and multi-seeded vegetables (like eggplant) are avoided to prevent the ingestion of mobile insects (trasa jiva) and microscopic life. Furthermore, Jain dietary law prohibits the consumption of products derived from already-dead animals.
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 binds and modulates the nuclear receptors REV-ERBα and REV-ERBβ. It is used in laboratory studies of circadian biology and metabolism, not as an approved medicine. It is also known by the informal name Stenabolic.