A practical reference on circadian rhythm: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-04-12 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic small-molecule REV-ERB agonist | Not a hormone or natural product |
| Primary targets | REV-ERBα and REV-ERBβ | Nuclear receptors involved in circadian and metabolic regulation |
| Appearance | White to off-white solid | Typical for purified research samples |
| Solubility | Soluble in DMSO and ethanol; low water solubility | Laboratory solubility depends on solvent and purity |
| Common synonyms | SR9009; Stenabolic | Stenabolic is a colloquial name, not a formal chemical name |
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.
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.
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 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.
Preclinical reports describe effects on exercise endurance, mitochondrial content, and lipid profiles in rodents, but these findings come from specific experimental conditions. Many studies use high doses or delivery methods that may not translate directly to human use. SR9009 has been reported to have low oral bioavailability and a short half-life, which complicates interpretation of oral dosing studies. It is not established as safe or effective for any indication. Literature discussions often separate its pharmacological mechanism from unverified claims made in fitness and supplement markets.
LnM(CO) + RO− → [LnM−C(=O)OR]− Some metal carbonyls react with azide to give isocyanato complexes with release of nitrogen. By adjusting the cone voltage or temperature, the degree of fragmentation can be controlled. The molar mass of the parent complex can be determined, as well as information about structural rearrangements involving loss of carbonyl ligands under ESI-MS conditions. Mass spectrometry combined with infrared photodissociation spectroscopy can provide vibrational informations for ionic carbonyl complexes in gas phase.
MrMed is an online pharmacy for super-specialty medicines based in India. It was founded by Devashish Singh and Saurab Jain and has its headquarters in Chennai. In 2022, the company received an award from the Government of Tamil Nadu for its contributions to healthcare.
=== Fetus earrings === During the 1984 exhibition of freeze-dried sculptures in London, Gibson was given two dehydrated human fetuses from an anatomy professor. They were 10 weeks in development and had been dehydrated for 20 years. Gibson re-hydrated both fetuses, freeze-dried them and attached them as earrings to a female mannequin head. The sculpture was titled Human Earrings. They were exhibited at the Young Unknowns Gallery in south London in December 1987. On Thursday, 3 December 1987, the sculpture was seized by the Metropolitan Police. Because of this incident, Gibson was expelled from Goldsmiths College on 21 December 1987, where he was studying post-graduate art, design and technology. On 11 April 1988, Gibson and the gallery owner, Peter Sylveire, were formally charged with the common law offences of exhibiting a public nuisance and outraging public decency. The trial started on Monday, 30 January 1989 at the Old Bailey in central London. The judge was Brian Smedley, Michael Worsley was the prosecuting barrister, and Geoffrey Robertson and Helena Kennedy were the defence barristers. On 6 February 1989, the charge of public nuisance was dismissed. On Tuesday, 9 February 1989, the jury of 10 women and 2 men found Gibson and Sylveire guilty of outraging public decency. Gibson was fined £500 and Sylveire was fined £300. Immediately following the verdict, an appeal application was filed. However, on 10 July 1990, the Court of Appeal dismissed the case and upheld the earlier conviction.
Corrective rape, also called curative rape or homophobic rape, is a hate crime in which somebody is raped because of their perceived sexual orientation or gender identity. The common intended consequence of the rape, as claimed by the perpetrator, is to turn the person heterosexual. The term was coined in South Africa after well-known cases of corrective rapes of lesbian women such as Eudy Simelane (who was also murdered in the same attack) and Zoliswa Nkonyana became public. Popularization of the term has raised awareness and encouraged LGBTQ+ people in countries across the world to come forward with their own stories of being raped as punishment for or in an attempt to change their sexual orientation or gender identity. Although some countries have laws protecting LGBTQ+ people, corrective rape is often overlooked. South African researcher Kylie Thomas offers a critique of the terms "corrective" and "curative" rape in her report, "Homophobia, Injustice and 'Corrective Rape' in Post-Apartheid South Africa".
The most common vehicle currently used for targeted drug delivery is the liposome. Liposomes are non-toxic, non-hemolytic, and non-immunogenic even upon repeated injections; they are biocompatible and biodegradable and can be designed to avoid clearance mechanisms (reticuloendothelial system (RES), renal clearance, chemical or enzymatic inactivation, etc.) Lipid-based, ligand-coated nanocarriers can store their payload in the hydrophobic shell or the hydrophilic interior depending on the nature of the drug/contrast agent being carried. The only problem to using liposomes in vivo is their immediate uptake and clearance by the RES system and their relatively low stability in vitro. To combat this, polyethylene glycol (PEG) can be added to the surface of the liposomes. Increasing the mole percent of PEG on the surface of the liposomes by 4-10% significantly increased circulation time in vivo from 200 to 1000 minutes. PEGylation of the liposomal nanocarrier elongates the half-life of the construct while maintaining the passive targeting mechanism that is commonly conferred to lipid-based nanocarriers. When used as a delivery system, the ability to induce instability in the construct is commonly exploited allowing the selective release of the encapsulated therapeutic agent in close proximity to the target tissue/cell in vivo. This nanocarrier system is commonly used in anti-cancer treatments as the acidity of the tumour mass caused by an over-reliance on glycolysis triggers drug release.
Sources: en.wikipedia.org
==== Cation attachment ==== In the process of cation attachment, cations (typically H+ or Na+) attach themselves to analyte molecules; the desorption of the cation attachment (e.g., MNa+) can then be realized through the emitter heating and high field. The ionization of more polar organic molecules (e.g., ones with aliphatic hydroxyl or amino groups) in FD-MS typically go through this mechanism.
After releasing Half-Life 2 in 2004, Valve began developing a trilogy of episodic sequels, planning to release shorter games more frequently. Half-Life 2: Episode One was released in 2006, followed by Episode Two in 2007, which ended on a cliffhanger. Episode Three was scheduled for 2008, but was canceled. The Half-Life: Alyx project lead, Robin Walker, said that Valve uses the Half-Life series to "solve some interesting collision of technology and art that had reared itself", but had failed to find a unifying idea that provided a sense of "wonderment, or opening, or expansion" for Episode Three. After the release of Left 4 Dead in 2008, Valve abandoned episodic development and made several failed attempts to develop further Half-Life projects. They decided to complete their new engine, Source 2, before beginning a new game, as developing Half-Life 2 and the Source engine simultaneously had created problems. In 2016 and 2017, the Half-Life writers Marc Laidlaw, Erik Wolpaw, Jay Pinkerton and Chet Faliszek left Valve. Coupled with Valve's support for their other franchises, journalists took the departures as an indicator that new Half-Life games were no longer in development. Walker blamed the lack of progress on Valve's flat management structure, whereby employees decide what to work on themselves. The team decided they would be happier if they worked together on a large project, even if it was not everyone's preferred choice. By 2013, Valve was experimenting with VR using Half-Life 2 as a basis.
via glucuronidation (30–50%): valproic acid β-O-glucuronide via beta oxidation (>40%): 2E-ene-valproic acid, 2Z-ene-valproic acid, 3-hydroxyvalproic acid, 3-oxovalproic acid via omega oxidation: 5-hydroxyvalproic acid, 2-propyl-glutaric acid some others: 3E-ene-valproic acid, 3Z-ene-valproic acid, 4-ene-valproic acid, 4-hydroxyvalproic acid All in all, over 20 metabolites are known. In adult patients taking valproate alone, 30–50% of an administered dose is excreted in urine as the glucuronide conjugate. The other major pathway in the metabolism of valproate is mitochondrial beta oxidation, which typically accounts for over 40% of an administered dose. Typically, less than 20% of an administered dose is eliminated by other oxidative mechanisms. Less than 3% of an administered dose of valproate is excreted unchanged (i.e., as valproate) in urine. Only a small amount is excreted via the faeces. Elimination half-life is 16±3 hours and can decrease to 4–9 hours when combined with enzyme inducers.
GLUTs are integral membrane proteins composed of 12 α-helix membrane spanning regions. The GLUT proteins are encoded by the SLC2 genes and categorized into three classes based on amino acid sequence similarity. Humans have been found to express fourteen GLUT proteins. Class I GLUTs include GLUT1, one of the most studied isoforms, and GLUT2. GLUT1 is found in various tissues like the red blood cells, brain, and blood-brain barrier and is responsible for basal glucose uptake. GLUT2 is predominantly found in the liver, pancreas, and small intestines. It plays an important role in insulin secretion from pancreatic beta cells. Class II includes the GLUT3 and GLUT4. GLUT3, primarily found in the brain, neurons and placenta, has a high affinity for glucose in facilitating glucose uptake into neurons. GLUT4 plays a role in insulin-regulated glucose uptake and is mainly found in insulin-sensitive tissues such as muscle and adipose tissue. Class III includes GLUT5, found in the small intestine, kidney, testes, and skeletal muscle. Unlike the other GLUTs, GLUT5 specifically transports fructose rather than glucose. Glucose transporters allow glucose molecules to move down their concentration gradient from areas of high glucose concentration to areas of low concentration. This process often involves bringing glucose from the extracellular space or blood into the cell. The concentration gradient set up by glucose concentrations fuels the process without the need for ATP.
A Calutron is a sector mass spectrometer that was used for separating the isotopes of uranium developed by Ernest O. Lawrence during the Manhattan Project and was similar to the Cyclotron invented by Lawrence. Its name is a concatenation of Cal. U.-tron, in tribute to the University of California, Lawrence's institution and the contractor of the Los Alamos laboratory. They were implemented for industrial scale uranium enrichment at the Oak Ridge, Tennessee Y-12 plant established during the war and provided much of the uranium used for the "Little Boy" nuclear weapon, which was dropped onto Hiroshima in 1945.
Sources: en.wikipedia.org
It is a synthetic research compound that activates REV-ERB nuclear receptors. It is not an approved drug or dietary supplement. Most information comes from cell and animal studies.
It binds REV-ERBα and REV-ERBβ and changes transcription of metabolic genes. This can affect circadian rhythm, lipid use, and mitochondrial function. The full downstream effects are still under study.
No. Some rodent studies show increased endurance, but controlled human trials are lacking. Claims about human performance are not established by published evidence.
The most common approach is liquid chromatography-tandem mass spectrometry, often after extraction from blood, urine, or tissue. Ultraviolet detection and nuclear magnetic resonance spectroscopy are used mainly for reference material characterization. Isotope-labeled internal standards improve accuracy.