circadian rhythm raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-04-13 and is reviewed periodically as new material appears.
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.
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.
SR9009 is often grouped with compounds studied for circadian and metabolic regulation rather than with classical anabolic steroids. Its interactions with nuclear receptors differ from those of androgen receptor ligands, and its proposed mechanisms involve transcriptional control rather than direct hormone signaling. Some sources classify it as a metabolic modulator because of observed effects on energy utilization. The distinction matters for regulation and for interpreting research results across different compound classes.
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.
| 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 |
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.
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.
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.
In rodent studies, SR9009 has been reported to increase mitochondrial content in skeletal muscle and improve exercise endurance under some conditions. These findings led to popular descriptions such as an exercise mimetic, although that term oversimplifies the biology. Effects vary by dose, timing, tissue, and model. The compound's influence on circadian pathways means that time of administration can matter in experiments. Whether similar metabolic changes occur in humans remains largely unexplored in controlled published trials.
Pharmacokinetic data for SR9009 are limited in published literature. Some reports indicate low oral bioavailability and rapid clearance in animals, which complicates interpretation of exposure and effect. Researchers often use injected routes in preclinical work to achieve measurable systemic levels. Analytical studies rely on mass spectrometry to detect the parent compound and its metabolites. Questions about tissue distribution, active metabolites, and long-term consequences remain open. Species differences in metabolism can affect observed half-life and target engagement.
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 and metabolic gene expression. In laboratory experiments, SR9009 binds these receptors and alters transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. It is not a naturally occurring compound and has no approved therapeutic use. Research interest stems from its ability to modify energy metabolism in cells and animal models.
==== Cyanobactins ==== Cyanobactin biosynthesis requires proteolytic cleavage of both N-terminal and C-terminal portions of the precursor peptide. The defining proteins are thus an N-terminal protease, referred to as the A protein, and a C-terminal protease, referred to as the G protein. The G protein is also responsible for macrocyclization. For cyanobactins, the precursor peptide is referred to as the E peptide. Minimally, the E peptide requires a leader peptide region, a core (structural) region, and both N-terminal and C-terminal protease recognition sequences. In contrast to most RiPPs, for which a single precursor peptide encodes a single natural product via a lone core peptide, cyanobactin E peptides can contain multiple core regions; multiple E peptides can even be present in a single gene cluster. Many cyanobactins also undergo heterocyclization by a heterocyclase (referred to as the D protein), installing oxazoline or thiazoline moieties from Ser/Thr/Cys residues prior to the action of the A and G proteases. The heterocyclase is an ATP-dependent YcaO homologue that behaves biochemically in the same manner as YcaO-domain cyclodehydratases in thiopeptide and linear azol(in)e-containing peptide (LAP) biosynthesis (described above). A common modification is prenylation of hydroxyl groups by an F protein prenyltransferase. Oxidation of azoline heterocycles to azoles can also be accomplished by an oxidase domain located on the G protein. Unusual for ribosomal peptides, cyanobactins can include D-amino acids; these can occur adjacent to azole or azoline residues.
National legislation for amendment of the Controlled Substances Act to place salvinorin A and Salvia divinorum in Schedule I at the federal level in the United States was proposed in 2002 by Representative Joe Baca (D- California). Those opposed to bill HR 5607 include Daniel Siebert, who sent a letter to Congress arguing against the proposed legislation, and the Center for Cognitive Liberty and Ethics (CCLE), who sent key members of the US Congress a report on Salvia divinorum and its active principle, along with letters from an array of scientists who expressed concern that scheduling Salvia divinorum would negatively impact important research on the plant. The bill did not pass. Although salvia is not regulated under the Controlled Substances Act, as of 2009, it had been made illegal in 13 states. Delaware banned it after salvia use was reported to have played a role in the suicide of a teenager. Alabama, Delaware, Illinois, Louisiana, Michigan, Missouri, Ohio, Texas, and other states have passed their own laws. Several other states have proposed legislation against salvia, including Alaska, California, Florida, Iowa, Maryland, New Jersey, New York, Oregon, and Pennsylvania. Many of these proposals have not made it into law, with motions having failed, stalled or otherwise died, for example at committee review stages. Where individual state legislation does exist, it varies from state to state in its prohibitive degree. Legal consequences may also exist even in states without bans on salvia in particular.
==== Tissue engineering in situ ==== In situ tissue regeneration is defined as the implantation of biomaterials (alone or in combination with cells and/or biomolecules) into the tissue defect, using the surrounding microenvironment of the organism as a natural bioreactor. This approach has found application in bone regeneration, allowing the formation of cell-seeded constructs directly in the operating room.
==== Ultrasonic couplant ==== Glycerol can be sometimes used as replacement for water in ultrasonic testing, as it has favourably higher acoustic impedance (2.42 MRayl versus 1.483 MRayl for water) while being relatively safe, non-toxic, non-corrosive and relatively low cost.
Sources: en.wikipedia.org
=== Vasopressin during surgery and anaesthesia === Vasopressin concentration is used to measure surgical stress for evaluation of surgical techniques. Plasma vasopressin concentration is elevated by noxious stimuli, predominantly during abdominal surgery, especially at gut manipulation, traction of viscera, as well as abdominal insufflation with carbon dioxide during laparoscopic surgery.
Repatriating the survivors of the 16 October strike on a semi-submersible to their home countries for prosecution avoids a civilian court challenge to continued detention without evidence, and a military court challenge to the legal justification for treating prisoners as unlawful combatants if they were not engaged in armed conflict.
CGRP mediates its effects through a heteromeric receptor composed of a G protein-coupled receptor called calcitonin receptor-like receptor (CALCRL) and RAMP1. CGRP receptors are found throughout all the body, suggesting that the protein may modulate a variety of physiological functions in all major systems (e.g., respiratory, endocrine, gastrointestinal, immune, and cardiovascular). These transmembrane receptors form folded accordion-like structures embedded in the cell membrane with loops of protein on the inside (intracellular loops) and outside (extracellular loops) of the membrane. The second extracellular loop is fundamental for ligand-induced activation, with key interactions of R274/Y278/D280/W283.
=== 2024–present: I'm a Celebrity... South Africa and Everything. All At Once === In April 2024, Collins made a guest appearance on the E4 reality series The Underdog: Josh Must Win, in which contestants believe they are competing on a reality show called The Favourite, however unbeknownst to them, the game is being controlled by Amber Gill, Nick Grimshaw, Pete Wicks and Vicky Pattison who must ensure that Josh, a non-typical reality show contestant, is declared the winner. Collins was enlisted to help with a photoshoot in which she assigned costumes to the contestants and advised them on various different poses. In May 2024, Collins appeared on the Daily Mail's podcast series Everything I Know About Me where she spoke about her life and career. In September 2024, Collins appeared on the BBC genealogy documentary series Who Do You Think You Are?. Collins was keen to learn more about her mother's side of the family, after she was fostered at birth and ultimately discovered that her grandmother was a diagnosed chronic schizophrenic who spent time in two psychiatric hospitals. Throughout the episode, she meets her distant cousins who reside in Dagenham near to where Collins grew up, and sees a photo of her grandmother for the first time. She also discovers that her ancestors lived on Dorset Street in Spitalfields, where Jack the Ripper is believed to have murdered his final victim Mary Jane Kelly in November 1888. In January 2025, she appeared on an episode of Pointless Celebrities alongside Hayley Hasselhoff, filmed two years prior.
== Contraindications == Etifoxine is contraindicated in people with circulatory shock, severe liver impairment, severe kidney impairment, myasthenia gravis, galactosemia (due to lactose in the drug formulation), severe respiratory failure, and hypersensitivity (allergy) to etifoxine. The medication is not recommended in children or adolescents under the age of 18 and is not recommended during pregnancy and breastfeeding due to insufficient data. Caution is warranted with regard to combining etifoxine and other central depressants such as benzodiazepines, central analgesics, antipsychotics, sedative antihistamines, and alcohol.
Sources: en.wikipedia.org
A G cell or gastrin cell is a type of cell in the stomach and duodenum that secretes gastrin. It works in conjunction with gastric chief cells and parietal cells. G cells are found deep within the pyloric glands of the stomach antrum, and occasionally in the pancreas and duodenum. The vagus nerve innervates the G cells. Gastrin-releasing peptide is released by the post-ganglionic fibers of the vagus nerve onto G cells during parasympathetic stimulation. The peptide hormone bombesin also stimulates gastrin from G cells. Gastrin-releasing peptide, as well as the presence of amino acids in the stomach, stimulates the release of gastrin from the G cells. Gastrin stimulates enterochromaffin-like cells to secrete histamine. Gastrin also targets parietal cells by increasing the amount of histamine and the direct stimulation by gastrin, causing the parietal cells to increase HCl secretion in the stomach. G-cells frequently express PD-L1 during homeostasis which protects them from Helicobacter pylori-induced immune destruction.
=== Durability === Mid-term durability from ESG appears promising. A total body weight loss of 17% and excess weight loss of between approximately 60-67% was observed to be sustained at 18–24 months. This was later confirmed in the multicenter, randomized controlled MERIT study, which observed that 68% of subjects who underwent an ESG maintained 25% or more of their excess weight loss at two years. As a novel therapy, ESG presently lacks studies assessing long-term durability, though more data on this component of ESG are anticipated as more ESGs are performed over time. One recent study observed at 5 years from ESG that at least 10% total body weight loss was maintained in 90% of patients and at least 15% total body weight loss was maintained in 61% of patients.
All triterpenoids are synthesized via the cyclization of the C30 isoprenoid chain, squalene. Eukaryotes use oxidosqualene cyclase and several other enzymes to create the tetracyclic skeleton found in steroids, a process that requires molecular oxygen. Bacteria use a similar enzyme (shc) to create the pentacyclic hopanoid precursor, diploptene; however, this biosynthesis does not require oxygen. It was recently discovered that tetrahymanol-producing bacteria form diploptene using shc then elongate the final cyclopentane into a fifth ring using tetrahymanol synthase (ths). It is unknown whether bacteria modify diploptene into other hopene molecules before creating tetrahymanol. It has also been found with a methylation at the C-3 site. Eukaryotes that live in anaerobic environments cannot synthesize their own sterols because of a lack of molecular oxygen. These organisms can gain sterols through predation. However, there can be times of sterol starvation. Tetrahymanol biosynthesis does not require oxygen, and can substitute readily for sterols. It is hypothesized that ciliates synthesize tetrahymanol in response to lack of oxygen and exogenous sterols. The gene for tetrahymanol synthase was found in the genomes of many genera of alpha-, delta-, and gammaproteobacteria, including Rhodopseudomonas, Bradyrhizobium and Methylomicrobium.
Electrosmog is colloquially understood as the exposure of humans and the environment to electric, magnetic and electromagnetic fields, some of which are believed to have undesirable biological effects. Electromagnetic environmental compatibility (EMC) refers to the effects on living organisms, some of which are considered electrosensitive. Fears of such effects have existed since the beginning of technological use in the mid-19th century. In 1890, for example, officials of the Royal General Directorate in Bavaria were forbidden to attend the opening ceremony of Germany's first alternating current power plant, the Reichenhall Electricity Works, or to enter the machine room. With the establishment of the first radio telegraphy and its telegraph stations, the U.S. magazine The Atlanta Constitution reported in April 1911 on the potential dangers of radio telegraph waves, which, in addition to "tooth loss," were said to cause hair loss and make people "crazy" over time. Full-body protection was recommended as a preventive measure. During the second half of the 20th century, other sources of electromagnetic fields have become the focus of health concerns, such as power lines, photovoltaic systems, microwave ovens, computer and television screens, security devices, radar equipment, and more recently, cordless telephones (DECT), cell phones, their base stations, energy-saving lamps, and Bluetooth connections. Electrified railroad lines, tram overhead lines and subway tracks are also strong sources of electrosmog.
==== Drug delivery ==== Emerging methods of drug delivery involving nanotechnological methods can be useful by improving bodily response, specific targeting, and non-toxic metabolism. Many nanotechnological methods and materials can be functionalized for drug delivery. Ideal materials employ a controlled-activation nanomaterial to carry a drug cargo into the body. Mesoporous silica nanoparticles (MSN) have increased in research popularity due to their large surface area and flexibility for various individual modifications while maintaining high-resolution performance under imaging techniques. Activation methods greatly vary across nanoscale drug delivery molecules, but the most commonly used activation method uses specific wavelengths of light to release the cargo. Nanovalve-controlled cargo release uses low-intensity light and plasmonic heating to release the cargo in a variation of MSN containing gold molecules. The two-photon activated photo-transducer (2-NPT) uses near infrared wavelengths of light to induce the breaking of a disulfide bond to release the cargo. Recently, nanodiamonds have demonstrated potential in drug delivery due to non-toxicity, spontaneous absorption through the skin, and the ability to enter the blood–brain barrier. The unique structure of carbon nanotubes also gives rise to many innovative inventions of new medical methods. As more medicine is made at the nano level to revolutionize the ways for human to detect and treat diseases, carbon nanotubes become a stronger candidate in new detection methods and therapeutic strategies.
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.
It is a synthetic REV-ERB agonist used mainly in preclinical research. It is not an approved medicine for human use.