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 2026-03-27. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C20H24ClN3O4S | Reported for the free base |
| Molecular weight | 437.9 g/mol | Calculated from the formula |
| Primary target | REV-ERBα and REV-ERBβ | Nuclear receptors involved in circadian regulation |
| Solubility | Soluble in DMSO and ethanol | Poorly soluble in water |
| Typical storage | -20 °C, desiccated | Protect from light and moisture |
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.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ, also called NR1D1 and NR1D2. These receptors help regulate circadian rhythms and metabolic gene programs. The compound was developed for laboratory research, not as an approved therapeutic. Its identity is distinct from steroid hormones and selective androgen receptor modulators. Scientific interest centers on how REV-ERB activation changes gene expression in cells and animal models.
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.
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.
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.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is not an approved medicine and has no established human therapeutic use. The compound appears in scientific literature as a tool for probing circadian and metabolic regulation. Online sellers often label it as a research chemical, sometimes using the nickname Stenabolic. Its chemical identity is distinct from selective androgen receptor modulators, stimulants, and peroxisome proliferator-activated receptor delta agonists. Researchers use it mainly in cell and animal experiments.
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.
In contrast, sleep-related hypoventilation occurs when there is a malfunction of the brain's drive to breathe. The underlying cause of the loss of the wakefulness drive to breathe encompasses a broad set of diseases from strokes to severe kyphoscoliosis.
=== Pharmacokinetics === The bioavailability of anastrozole in humans is unknown, but it was found to be well-absorbed in animals. Absorption of anastrozole is linear over a dosage range of 1 to 20 mg/day in humans and does not change with repeated administration. Food does not significantly influence the extent of absorption of anastrozole. Peak levels of anastrozole occur a median 3 hours after administration, but with a wide range of 2 to 12 hours. Steady-state levels of anastrozole are achieved within 7 to 10 days of continuous administration, with 3.5-fold accumulation. However, maximal suppression of estradiol levels occurs within 3 or 4 days of therapy. Active efflux of anastrozole by P-glycoprotein at the blood–brain barrier has been found to limit the central nervous system penetration of anastrozole in rodents, whereas this was not the case with letrozole and vorozole. As such, anastrozole may have peripheral selectivity in humans, although this has yet to be confirmed. In any case, estradiol is synthesized peripherally and readily crosses the blood–brain barrier, so anastrozole would still expected to reduce estradiol levels in the central nervous system to a certain degree. The plasma protein binding of anastrozole is 40%. The metabolism of anastrozole is by N-dealkylation, hydroxylation, and glucuronidation. Inhibition of aromatase is due to anastrozole itself rather than to metabolites, with the major circulating metabolite being inactive. The elimination half-life of anastrozole is 40 to 50 hours (1.7 to 2.1 days).
== Pharmacokinetics == The metabolism of topically applied nitrofurazone is thought to be by 5-nitro reduction and cleavage of the -CH=N- linkage to generate a reactive species which can covalently bond to cellular macromolecules, none of the end products are thought to be antimicrobial.
== Function == 5-HEDH functions as a highly specific oxidizer of 5(S)-HETE to 5-oxo-ETE; no functional importance has yet been ascribed to its ability in similarly oxidizing other 5(S)-hydroxyl fatty acids. 5-Oxo-ETE stimulates a wide range of biological activities far more potently and powerfully than 5(S)-HETE. For example, it is 30–100-fold more potent in stimulating cells that promote inflammation and allergy reactions such as neutrophils, monocytes, macrophages, eosinophils, and basophils and is more potent than 5-HETE in stimulating various types of cancer cells to grow. Furthermore, 5-oxo-ETE appears to be involved in various animal and human reactions: injected into the skin of rabbits, it causes a severe edema with an inflammatory cell infiltrate resembling an urticaria-like lesion; it is present in bronchoalveolar lavage fluid from cats undergoing experimentally induced asthma; it stimulates the local accumulation of eosinophils, neutrophils, and monocytes when injected into the skin of humans; and it has been extracted from scales of psoriatic patients. Most if not all of these allergic and inflammatory conditions as well as rapidly growing cancerous lesions are associated with oxidative stress. Studies therefore suggest that 5-HEDH contributes to the development and progression of these reactions and diseases by being responsible for generating 5-oxo-ETE.
The most widely used method to determine absolute molar mass is size-exclusion chromatography (SEC) coupled with multi-angle laser light scattering (MALS). SEC can separate macromolecules based on their size by passing an analyte containing molecules of different sizes through a column containing porous substrate. Larger components of the analyte spend less time traveling through these pores and therefore elute faster, while smaller components can access more of these pores and are therefore retained longer. However, molar masses determined through SEC require calibration curves constructed from standards, and calculating absolute molar masses require absolute detection systems. The two primary detection systems used to determine absolute molar mass are light scattering photometers and viscometers. Static light scattering (SLS) experiments measure the difference between the light scattered by a dilute solution and the light scattered through pure solvent. Given a dilute enough solution and at an angle of θ = 0° between the incident light and the scattering direction, this difference, known as the excess Rayleigh ratio ΔR(θ), can be approximately related to the weight-average molar mass Mw through the equation:
Sources: en.wikipedia.org
Without this reactivity reserve, a reactor shutdown would preclude its restart for several tens of hours until 135I/135Xe sufficiently decays, especially shortly before replacement of spent fuel (with high burnup and accumulated nuclear poisons) with fresh fuel. Fluid fuel reactors cannot develop xenon inhomogeneity because the fuel is free to mix. Also, the Molten Salt Reactor Experiment demonstrated that spraying the liquid fuel as droplets through a gas space during recirculation can allow xenon and krypton to leave the fuel salts.
=== Non-intoxicating effects === Cannabidiol does not appear to have any intoxicating effects such as those caused by ∆9-THC in cannabis, but it is under preliminary research for its possible anxiolytic and antipsychotic effects. As the legal landscape and understanding about the differences in medical cannabinoids unfolds, experts are working to distinguish "medical cannabis" (with varying degrees of psychotropic effects and deficits in executive function) from "medical CBD therapies", which would commonly present as having a reduced or non-psychoactive side-effect profile. Various strains of "medical cannabis" are found to have a significant variation in the ratios of CBD-to-THC and are known to contain other non-psychotropic cannabinoids. Any psychoactive cannabis, regardless of its CBD content, is derived from the flower (or bud) of the genus Cannabis. As defined by US federal law, non-psychoactive hemp (also commonly termed "industrial hemp"), regardless of its CBD content, is any part of the cannabis plant, whether growing or not, containing a ∆9-tetrahydrocannabinol concentration of no more than 0.3% on a dry-weight basis. In the United States, certain standards are required for legal growing, cultivating, and producing the hemp plant, but there are no federal standards for quality being enforced in the hemp industry. Certain state regulations are in place, but vary state to state. For instance, the Colorado Industrial Hemp Program registers growers of industrial hemp and samples crops to verify that the dry-weight THC concentration does not exceed 0.3%.
=== Woodhouse Grammar School === After the First World War, the former residence of ornamental plasterer Thomas Collins (1735–1830) in the Woodhouse area of Finchley was reconstructed; the house became The Woodhouse School in 1923. A blue plaque commemorating Thomas Collins is on the wall outside the present college office. The school coat of arms with the motto 'Cheerfulness with Industry' is still displayed above the stage in the college hall. During the Second World War, the school continued to function while the basement was used by the ARP service. The names of the forty-seven former pupils who died during WWII are recorded in a hand-illuminated Roll of Honour which hangs at the foot of the main staircase near the front entrance to the college. The Roll of Honour also records the names of the four houses of the old grammar school: Gordon, Livingstone, Nightingale and Scott.
Lipofuscin accumulation in the eye is a major risk factor implicated in macular degeneration, a degenerative disease, and Stargardt disease, an inherited juvenile form of macular degeneration. In the peripheral nervous system, abnormal accumulation of lipofuscin known as lipofuscinosis is associated with a family of neurodegenerative disorders – neuronal ceroid lipofuscinoses, the most common of these is Batten disease. Also, pathological accumulation of lipofuscin is implicated in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, certain lysosomal diseases, acromegaly, denervation atrophy, lipid myopathy, chronic obstructive pulmonary disease, and centronuclear myopathy. Accumulation of lipofuscin in the colon is the cause of the condition melanosis coli. On the other hand, myocardial lipofuscin accumulation more directly reflects chronological ageing rather than human cardiac pathology.
=== OECD === In October 2021, Castillo sent a letter to the secretary-general of the Organisation for Economic Co-operation and Development (OECD), Mathias Cormann, to ratify Peru's willingness to join the organization. In January 2022, Castillo signed the invitation letter to begin Peru's accession process to the OECD.
Sources: en.wikipedia.org
The thomson (symbol: Th) is a unit that has appeared infrequently in scientific literature relating to the field of mass spectrometry as a unit of mass-to-charge ratio. The unit was proposed by R. Graham Cooks and Alan L. Rockwood naming it in honour of J. J. Thomson, who measured the mass-to-charge ratio of electrons and ions.
Conversely, the catabolic effect was much less in an older male, and no such effect was observed in adult females consuming a diet with sufficient calories and protein. The catabolic effects of CPA were found to be greater than those of corticosteroids. Although higher doses of CPA are necessary for considerable systemic AR antagonistic activity, it is notable that even low doses of oral CPA appear to be able to significantly antagonize AR signaling in the liver in women. This may be related to the hepatic first-pass effect of oral administration, and is evidenced by the fact that whereas combined birth control pills containing CPA increase SHBG levels by 300 to 400%, combined birth control pills containing various other progestins, with either androgenic or antiandrogenic activity, increase SHBG levels by only 50 to 300%. This is relevant as estrogens stimulate hepatic SHBG production while androgens inhibit hepatic SHBG production, and vice versa for their antagonists. The antiandrogenic activity of CPA may also be responsible for the relatively greater risk of venous thromboembolism with CPA-containing birth control pills compared to those containing other progestins. In rats, a dosage of CPA of 25 mg/kg/day results in complete regression of prostate gland growth in gonadally intact males. The equivalent dosage in humans, on the basis of body surface (conversion factor from rat to human of 6), was estimated to be approximately 4 mg/kg/day, or around 300 mg/day CPA for a 75 kg (165 lb) man.
26 February: A wildfire engulfs over 70 hectares of land near Waipoua Settlement, leading to the evacuation of local residents. Justice Minister Paul Goldsmith and Associate Justice Minister Nicole McKee confirm the Government will introduce legislation expanding citizen's arrest powers that they claim will combat retail crime. Foreign Minister Winston Peters met with Chinese Foreign Minister Wang Yi to raise concerns about Chinese naval exercises in the Tasman Sea. Police confirm they have issued a warrant to arrest a 44-year old man in connection with the arson of four Masterton churches on 22 February. 27 February – The New Zealand Government confirms it will introduce legislation to extend the parliamentary term from three to four years, subject to a referendum. 28 February: High Court Justice Simon Moore quashes Whakaari Management Limited's conviction for its role in the 2019 Whakaari / White Island eruption. Sarah Fitt resigns as chief executive of state pharmaceutical agency Pharmac. Oranga Tamariki workers affiliated with Public Service Association launch a seven-week strike avoiding double shifts, being on-call, and working overtime to protest unsatisfactory pay and work conditions.
The society – which only admitted men at the time – initially mistook Benett for a man due to her reputation as a scientist and her unusual first name, addressing her diploma of admission to "Dominum" (Master) Benett. 1840: Scottish fossil collector and illustrator Lady Eliza Maria Gordon-Cumming invited geologists Louis Agassiz, William Buckland and Roderick Murchison to examine her collection of fish fossils. Agassiz confirmed several of Gordon-Cumming's discoveries as new species. 1843: During a nine-month period in 1842–43, English mathematician Ada Lovelace translated Luigi Menabrea's article on Charles Babbage's newest proposed machine, the Analytical Engine. With the article, she appended a set of notes. Her notes were labelled alphabetically from A to G. In note G, she describes an algorithm for the Analytical Engine to compute Bernoulli numbers. It is considered the first published algorithm ever specifically tailored for implementation on a computer, and Ada Lovelace has often been cited as the first computer programmer for this reason. The engine was never completed, so her program was never tested. 1843: British botanist and pioneering photographer Anna Atkins self-published her book Photographs of British Algae, illustrating the work with cyanotypes. Her book was the first book on any subject to be illustrated by photographs. 1846: British zoologist Anna Thynne built the first stable, self-sustaining marine aquarium.
Sources: en.wikipedia.org
It is a synthetic REV-ERB agonist used mainly in preclinical research. It is not an approved medicine for human use.
It binds to REV-ERBα and REV-ERBβ, nuclear receptors involved in circadian and metabolic gene regulation. This can alter transcription of genes related to lipid and glucose metabolism in experimental models.
No controlled human trials have established that effect. Endurance findings come primarily from rodent studies, and human responses remain unknown.
SR9009 is a synthetic compound investigated as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is used in preclinical research on circadian rhythm and metabolism. It is not an approved drug.