The short version of circadian clock fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-03-14. Anything still debated is marked as such rather than presented as settled.
SR9009 is generally described as poorly soluble in water and more soluble in organic solvents such as dimethyl sulfoxide and ethanol. Stock solutions are commonly prepared in an organic solvent before dilution into an aqueous buffer or vehicle. Precipitation can occur if the organic fraction is reduced too quickly or if the final concentration exceeds the compound's solubility limit. Sonication or gentle warming may aid dissolution in some protocols, but excessive heat can promote degradation. Container material and pH can also influence observed solubility.
For long-term storage, SR9009 is typically kept as a solid at low temperature, protected from moisture and light. Desiccated conditions limit hydrolysis, while opaque containers reduce photochemical breakdown. Solutions are less stable than solids and are often stored frozen in aliquots to avoid repeated freeze-thaw cycles. Stability data are not standardized across all suppliers, so users should rely on certificate-of-analysis information when available. Degradation may appear as color change, precipitate, or decreased chromatographic purity.
SR9009 is a synthetic small molecule developed as an agonist of the nuclear receptors REV-ERBα (NR1D1) and REV-ERBβ (NR1D2). These receptors help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, SR9009 alters transcription of genes involved in lipid metabolism, inflammation, and mitochondrial function. It is not an approved medicine, and its pharmacological profile in humans remains largely uncharacterized. The compound is frequently discussed in the context of circadian biology and metabolic research rather than clinical use.
Preclinical reports have linked SR9009 to improved endurance and altered energy expenditure in rodents. Such findings have prompted interest in whether REV-ERB activation can influence skeletal muscle metabolism. However, the reported effects depend on dose, route, and experimental model, and replication across laboratories is limited. Human trials have not established comparable outcomes, so claims about exercise performance remain speculative. The absence of controlled human data is a central limitation in interpreting these observations.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Visual inspection is not sufficient for identity. |
| Solubility | Soluble in DMSO and ethanol | Low solubility in water; stock solutions use organic solvent. |
| Storage | -20°C, desiccated, protected from light | Limits hydrolysis and photodegradation. |
| Analytical method | HPLC-UV/MS | Used for identity and purity assessment. |
| Synonyms | SR9009, Stenabolic | Naming varies by supplier. |
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.
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. 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.
Analytical identification and purity assessment often use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Liquid chromatography–tandem mass spectrometry is used to detect and quantify SR9009 in biological matrices, including urine and blood, for anti-doping or pharmacokinetic studies. Nuclear magnetic resonance spectroscopy can confirm molecular structure. Stability depends on form and storage: the solid is generally more stable than solutions, and repeated freeze–thaw cycles may degrade samples. Purity is typically reported as a percentage from a certificate of analysis.
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.
Nicotinate riboside kinase (EC 2.7.1.173, ribosylnicotinic acid kinase, nicotinic acid riboside kinase, NRK1) is an enzyme that in humans is encoded by the genes NMRK1 and NMRK2. Its systematic name ATP:beta-D-ribosylnicotinate 5-phosphotransferase, and it catalyses the following chemical reaction:
transcriptional bursting The intermittent nature of transcription and translation mechanisms. Both processes occur in "bursts" or "pulses", with periods of gene activity separated by irregular intervals.
Carbon nanotubes are modelled in a similar manner as traditional composites in which a reinforcement phase is surrounded by a matrix phase. Idealized models such as cylindrical, hexagonal and square models are common. The size of the micromechanics model is a function of the studied mechanical properties. The concept of representative volume element (RVE) is used to determine the appropriate size and configuration of the computer model to replicate the actual behavior of the CNT-reinforced nanocomposite. Depending on the material property of interest (thermal, electrical, modulus, creep), one RVE might predict the property better than the alternatives. While the implementation of the ideal model is computationally efficient, they do not represent microstructural features observed in scanning electron microscopy of actual nanocomposites. To incorporate realistic modeling, computer models are also generated to incorporate variability such as waviness, orientation and agglomeration of multiwall or single-wall carbon nanotubes.
Sources: en.wikipedia.org
Each member of the population typically progresses from susceptible to infectious to recovered. This can be shown as a flow diagram in which the boxes represent the different compartments and the arrows the transition between compartments (see diagram).
An outbreak of avian botulism leads to the deaths of about 1,000 birds at the Waikouaiti wastewater treatment plant near Dunedin and the Washdyke Lagoon near Timaru. 27 January – New Zealand Foreign Minister Winston Peters' suspends New Zealand's aid programme to Kiribati after Kiribati President Taneti Maamau cancelled three pre-arranged meetings including one scheduled for mid January 2025. The New Zealand Government had wanted to discuss how NZ$102 million worth of aid money allocated to Kiribati between 2021 and 2024 was being spent. 29 January: Prime Minister Luxon and Transport Minister Chris Bishop announces plans by the Government to reverse blanket speed limits on 38 sections of the New Zealand state highway network and seek public consultation on raising the speed limits for another 49 state highway sections. Advocacy group Toitū te Tiriti files an urgent Waitangi Tribunal claim against proposed Regulatory Standards Bill, claiming it would undermine the Treaty of Waitangi. 30 January: Mount Taranaki is officially recognised as a person under the name Taranaki Maunga. The $130 million Queenstown Town Centre arterial road opens. 31 January: Health Minister Simeon Brown confirms that a new Dunedin Hospital will be built on the site of the former Cadbury factory at a cost of NZ$1.9 billion. A power outage affects 22,000 Transpower customers in Rotorua. The Royal New Zealand Air Force formally retires its fleet of five C-130H Hercules planes.
==== SEC/IEC ==== Hydrophobic interactions in protein SEC are relatively weak at low ionic strength, electrostatic effects may contribute significantly to retention, and this allows us to use an SEC column as a weak ion exchanger.
Sources: en.wikipedia.org
Around 90% of the protein structures available in the Protein Data Bank have been determined by X-ray crystallography. This method allows one to measure the three-dimensional (3-D) density distribution of electrons in the protein, in the crystallized state, and thereby infer the 3-D coordinates of all the atoms to be determined to a certain resolution. Roughly 7% of the known protein structures have been obtained by nuclear magnetic resonance (NMR) techniques. For larger protein complexes, cryo-electron microscopy can determine protein structures. The resolution is typically lower than that of X-ray crystallography, or NMR, but the maximum resolution is steadily increasing. This technique is still a particularly valuable for very large protein complexes such as virus coat proteins and amyloid fibers. General secondary structure composition can be determined via circular dichroism. Vibrational spectroscopy can also be used to characterize the conformation of peptides, polypeptides, and proteins. Two-dimensional infrared spectroscopy has become a valuable method to investigate the structures of flexible peptides and proteins that cannot be studied with other methods. A more qualitative picture of protein structure is often obtained by proteolysis, which is also useful to screen for more crystallizable protein samples. Novel implementations of this approach, including fast parallel proteolysis (FASTpp), can probe the structured fraction and its stability without the need for purification.
=== Hypoglycemia === Hypoglycemia, or low blood glucose, can happen even with care, since insulin requirements can change without warning. Some common reasons for hypoglycemia include increased or unplanned exercise, illness, or medication interactions, where another medication potentiates the effects of the insulin. Vomiting and diarrhea episodes can bring on a hypoglycemia reaction, due to dehydration or simply a case of too much insulin and not enough properly digested food. Symptoms of hypoglycemia need to be taken seriously and addressed promptly. Since serious hypoglycemia can be fatal, it is better to treat a suspected incident than to fail to respond quickly to the signs of actual hypoglycemia. Dr. Audrey Cook addressed the issue in her 2007 article on diabetes mellitus: "Hypoglycemia is deadly; hyperglycemia is not. Owners must clearly understand that too much insulin can kill, and that they should call a veterinarian or halve the dose if they have any concerns about a pet's well-being or appetite. Tell owners to offer food immediately if the pet is weak or is behaving strangely."
=== EC 1.5.99 With unknown physiological acceptors === EC 1.5.99.1: Now EC 1.5.8.3, sarcosine dehydrogenase EC 1.5.99.2: Now EC 1.5.8.4, dimethylglycine dehydrogenase EC 1.5.99.3: L-pipecolate dehydrogenase EC 1.5.99.4: nicotine dehydrogenase EC 1.5.99.5: methylglutamate dehydrogenase EC 1.5.99.6: spermidine dehydrogenase EC 1.5.99.7: Now EC 1.5.8.2, trimethylamine dehydrogenase EC 1.5.99.8: Now EC 1.5.5.2, proline dehydrogenase EC 1.5.99.9: transferred to EC 1.5.98.1, methylenetetrahydromethanopterin dehydrogenase EC 1.5.99.10: Now EC 1.5.8.1, dimethylamine dehydrogenase EC 1.5.99.11: transferred to EC 1.5.98.2, 5,10-methylenetetrahydromethanopterin reductase EC 1.5.99.12: cytokinin dehydrogenase EC 1.5.99.13: D-proline dehydrogenase EC 1.5.99.14: 6-hydroxypseudooxynicotine dehydrogenase EC 1.5.99.15: dihydromethanopterin reductase (acceptor)
Sources: en.wikipedia.org
Liquid chromatography with mass spectrometry is a common approach. Ultraviolet detection and nuclear magnetic resonance can support identification when suitable standards are available.
The solid is generally kept cold, dry, and protected from light. Solutions are often frozen in single-use aliquots to reduce repeated freeze-thaw cycles.
It indicates a material sold for laboratory study, not for human use. The label does not guarantee pharmaceutical purity, sterility, or regulatory approval.
It is a synthetic compound that acts as an agonist at REV-ERBα and REV-ERBβ. It is used mainly as a research chemical to study circadian and metabolic pathways. It is not approved for human therapeutic use.