A practical reference on circadian clock: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-03-03. Anything still debated is marked as such rather than presented as settled.
REV-ERB proteins help regulate daily cycles in gene expression, including genes tied to lipid and glucose metabolism. SR9009 binds these receptors and alters their activity in cell and animal experiments. Consequences observed in rodents include changes in skeletal muscle oxidative capacity, blood lipid levels, and exercise performance. The precise chain from receptor occupancy to whole-body effects is still an active area of study. Human responses cannot be assumed from rodent data.
Most published work on SR9009 consists of preclinical studies. It is widely sold as a research chemical, a category that does not imply safety, efficacy, or pharmaceutical-grade quality. Sports anti-doping organizations have listed SR9009 as a prohibited substance, and its presence in an athlete sample can lead to sanctions. Legal status differs by country; in several jurisdictions it is not approved for human consumption and may be treated as an unapproved new drug.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Common name | SR9009 | Also referred to as Stenabolic in non-scientific contexts. |
| Chemical class | Synthetic small molecule | Not a steroid or peptide hormone. |
| Receptor target | REV-ERBα and REV-ERBβ | Nuclear receptor agonist in preclinical studies. |
| Development status | Investigational | No approved human therapeutic indication. |
| Regulatory attention | Prohibited in sport | Listed by anti-doping authorities. |
Scientific discussion of SR9009 often separates animal evidence from human anecdote. Rodent studies provide controlled data on endurance, metabolism, and gene expression, but they use specific strains, doses, and treatment durations. Human reports are mostly uncontrolled and cannot establish cause and effect. Open questions include oral bioavailability, tissue distribution, metabolic stability, and long-term effects. Review articles generally call for more rigorous pharmacokinetic and safety research before any clinical use could be considered.
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.
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.
=== Flame retardants === Compounds of boron, silicon, arsenic, and antimony have been used as flame retardants. Boron, in the form of borax, has been used as a textile flame retardant since at least the 18th century. Silicon compounds such as silicones, silanes, silsesquioxane, silica, and silicates, some of which were developed as alternatives to more toxic halogenated products, can considerably improve the flame retardancy of plastic materials. Arsenic compounds such as sodium arsenite or sodium arsenate are effective flame retardants for wood but have been less frequently used due to their toxicity. Antimony trioxide is a flame retardant. Aluminium hydroxide has been used as a wood-fibre, rubber, plastic, and textile flame retardant since the 1890s. Apart from aluminium hydroxide, use of phosphorus based flame-retardants – in the form of, for example, organophosphates – now exceeds that of any of the other main retardant types. These employ boron, antimony, or halogenated hydrocarbon compounds.
== Associated disease states and abnormalities == Abnormal GnSAF bioactivity has been associated with premature surges in LH and LH hypersecretion. Optimal and timely changes in serum LH concentrations are crucial to ensuring the viability of oocytes and implantation after fertilization. For successful implantation of a zygote, the mid-cycle LH surge after the decline of GnSAF and ovulation must correspond with uterine receptivity. Hypersecretion of LH contributes to cycle disturbance, infertility and increased chances of miscarriage. GnSAF has been implicated in polycystic ovary syndrome (PCOS), one of the most common ovarian disorders responsible for causing anovulatory infertility. Approximately 40% of women with PCOS display higher GnRH pulse frequency and tonic hypersecretion of LH due to hypersecretion of androgens from the polycystic ovary. Androgens are readily metabolized to estradiol in the ovaries. The supraphysiological concentrations of estradiol maintains high pituitary responsiveness to GnRH, permitting the hypersecretion of LH. Superovulation is common in women who take medications such as clomiphene citrate, an anti-estrogenic oral medication used to treat infertility. Superovulation is induced in women to increase chances of fertilization and conception in assisted reproductive techniques. In naturally superovulating women, the mid-cycle LH surge is significantly lower compared to that of normal ovulating women due to the presence of GnSAF in the late follicular phase fluid.
=== Dermis === The dermis lies next to the epidermis. It is a 1–2 mm layer mainly composed of fibroblasts and immune cells (e.g. dermal dendritic cells, macrophages, T cells, mast cells) in a collagen and elastic fiber extracellular matrix. These immune cells play important roles in parasitic infections, psoriasis induction, tumor progression, dermal inflammation, angiogenesis, wound healing, tissue remodeling, skin sensitization, and tolerance. Therefore, the regional accumulation of drugs in the dermis is necessary for the prevention and treatment of these local skin diseases. The hair follicle is an invagination of epidermis cells deep into the dermis. The follicular route is critical in the topical delivery of particle-based formulations and hydrophilic, high-molecular-weight drugs. The follicular route provides benefits such as deeper penetration, prolonged residence duration, faster entry into the skin, and site-specific targeting.
== Reactivity == Active esters are mainly used as acylating agents. They undergo the same reactions as their unactivated analogues but do so more rapidly. They are prone to hydrolysis, for example. Of great interest is the enhanced reactivity of active esters toward amines to give amides.
== History == The first few amino acids were discovered in the early 1800s. In 1806, French chemists Louis-Nicolas Vauquelin and Pierre Jean Robiquet isolated a compound from asparagus that was subsequently named asparagine, the first amino acid to be discovered. Cystine was discovered in 1810, although its monomer, cysteine, remained undiscovered until 1884. Glycine and leucine were discovered in 1820. The last of the 20 common amino acids to be discovered was threonine in 1935 by William Cumming Rose, who also determined the essential amino acids and established the minimum daily requirements of all amino acids for optimal growth. The unity of the chemical category was recognized by Wurtz in 1865, but he gave no particular name to it. The first use of the term "amino acid" in the English language dates from 1898, while the German term, Aminosäure, was used earlier. Proteins were found to yield amino acids after enzymatic digestion or acid hydrolysis. In 1902, Emil Fischer and Franz Hofmeister independently proposed that proteins are formed from many amino acids, whereby bonds are formed between the amino group of one amino acid with the carboxyl group of another, resulting in a linear structure that Fischer termed "peptide".
Sources: en.wikipedia.org
== Medical uses == Vortioxetine is used as a treatment for major depressive disorder, with its effectiveness shown to be similar to other antidepressants and its effect size has been described as modest. Vortioxetine may be used when other treatments have failed. A 2017 Cochrane review on vortioxetine determined that its place in the treatment of severe depression is unclear due to low-quality evidence and that more studies comparing vortioxetine to selective serotonin reuptake inhibitors (SSRIs), the typical first-line treatments, are needed. Vortioxetine appears to work in depressed patients with anxiety. Vortioxetine is also used off label for anxiety. A 2016 review found it was not useful in generalized anxiety disorder at 2.5, 5.0, and 10 mg doses (15 and 20 mg doses were not tested). A 2019 meta-analysis found that vortioxetine did not produce statistically significant results over placebo in the symptoms, quality of life, and remission rates of generalized anxiety disorder, but it was well-tolerated. However, a 2018 meta-analysis supported use and efficacy of vortioxetine for generalized anxiety disorder, though stated that more research was necessary to strengthen the evidence. A 2021 systematic review and meta-analysis concluded that there was uncertainty about the effectiveness of vortioxetine for anxiety due to existing evidence being of very low-quality.
==== Dismantling clean energy initiatives ==== The nonpartisan think tank Energy Innovation found that the bill's efforts to dismantle clean energy incentives would cost more than 830,000 jobs across the country. Cutting clean energy incentives would also raise energy costs for households, with wholesale power prices rising by roughly fifty percent by 2035 due to the loss of new generation capacity.
Variational autoencoders (VAEs) are deep learning models that probabilistically encode data. They are typically used for tasks such as noise reduction from images, data compression, identifying unusual patterns, and facial recognition. Unlike standard autoencoders, which compress input data into a fixed latent representation, VAEs model the latent space as a probability distribution, allowing for smooth sampling and interpolation between data points. The encoder ("recognition model") maps input data to a latent space, producing means and variances that define a probability distribution. The decoder ("generative model") samples from this latent distribution and attempts to reconstruct the original input.
The large intestine forms an arch starting at the cecum and ending at the rectum and anal canal. It also includes the appendix, which is attached to the cecum. Its length is about 1.5 m, and the area of the mucosa in an adult human is about 2 m2 (22 sq ft). The longest part of the large intestine is the colon whose main function is to absorb water and salts. The large intestine begins at the cecum, where the appendix is located. This is also the start of the colon as the ascending colon in the back wall of the abdomen. At the right colic flexure (hepatic flexure) (the flexed portion of the ascending and transverse colon) it runs across the abdomen in the transverse colon, passing below the diaphragm. At the left colic flexure (splenic flexure) the flexed portion of the transverse and descending colon, it descends down the left side of the abdomen. It reaches the sigmoid colon which is a loop of the colon closest to the rectum and continues to the rectum and anal canal.
The many-banded krait (Bungarus multicinctus) is the second most venomous krait species known, based on toxinological studies conducted on mice. The venom of the many-banded krait consists of both pre- and postsynaptic neurotoxins (known as α-bungarotoxins and β-bungarotoxins, among others). Due to poor response to antivenom therapy, mortality rates are very high in cases of envenomation – up to 50% of cases that receive antivenom are still fatal. Case fatality rates of the many-banded krait envenoming reach 77–100% without treatment. The average venom yield from specimens kept on snake farms was between 4.6 and 18.4 mg per bite. In another study, the average venom yield was 11 mg (Sawai, 1976). The venom is possibly the most toxic of any Bungarus (krait) species and possibly the most toxic of any snake species in Asia, with LD50 values of 0.09 mg/kg–0.108 mg/kg SC, 0.113 mg/kg IV and 0.08 mg/kg IP on mice. Based on several LD50 studies, the many-banded krait is among the most venomous land snakes in the world. The Taiwan National Poison Control Center reports that the chief cause of death from snakebite during the decade (2002–2012) was respiratory failure, with 80% of these caused by bites from the many-banded krait.
Sources: en.wikipedia.org
It is a synthetic compound studied as an agonist of REV-ERB nuclear receptors. It is not an approved medicine and has mainly been examined in laboratory and animal research.
No. It is a small molecule that binds nuclear receptors involved in circadian regulation. Its classification differs from anabolic steroids or peptide hormones.
Published human clinical trial data are lacking. Most safety and activity information comes from preclinical models, so effects in people remain uncertain.
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.