A practical reference on circadian rhythm: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-01-12. 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.
Laboratory identification of SR9009 typically relies on chromatographic separation coupled to mass spectrometry, often with ultraviolet detection as a secondary check. Nuclear magnetic resonance spectroscopy can confirm molecular structure when a reference standard is available. Because many suppliers sell the compound as a research chemical, independent identity testing is important for experimental reproducibility. A single retention time is not sufficient proof of identity, especially when related compounds may be present. Purity assessments usually report a percentage based on area normalization.
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.
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.
| 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. |
Handling practices for SR9009 focus on minimizing degradation and contamination. The solid is generally stored desiccated at or below -20 °C, protected from light and moisture. Stock solutions are often prepared in dimethyl sulfoxide or ethanol, then aliquoted to avoid repeated freeze–thaw cycles. Aqueous solubility is low, so formulations for animal studies may require cosolvents or suspending agents. Personnel should follow institutional chemical safety procedures, because toxicological data for humans are incomplete.
Regulatory status varies by country and intended use. Major drug agencies have not granted marketing authorization for SR9009 as a medicine, and it is not listed as a controlled substance in many jurisdictions. It is often sold as a research chemical, a category that may fall outside pharmaceutical manufacturing rules. Buyers should verify local laws and supplier documentation, including certificates of analysis. The lack of standardized quality controls raises concerns about identity, purity, and actual content in products marketed online.
In laboratory settings, SR9009 is commonly identified by its molecular structure and its interaction with REV-ERB receptors. Vendors may list it under synonyms such as Stenabolic or REV-ERB agonist, but those names do not define purity or identity. Analytical confirmation typically uses high-performance liquid chromatography with ultraviolet detection or liquid chromatography–mass spectrometry. A reference standard is needed to compare retention time and mass spectrum, because the compound can be confused with related research chemicals.
Melarsoprol is an arsenic-containing medication used for the treatment of sleeping sickness (African trypanosomiasis). It is specifically used for second-stage disease caused by Trypanosoma brucei rhodesiense when the central nervous system is involved. For Trypanosoma brucei gambiense, eflornithine or fexinidazole is usually preferred. It is effective in about 95% of people. It is given by injection and is known by patients as "fire in the veins". Melarsoprol has a high number of side effects. Common side effects include brain dysfunction, numbness, rashes, and kidney and liver problems. About 1–5% of people die during treatment, although this is tolerated due to sleeping sickness itself having a practically 100% mortality rate when untreated. In those with glucose-6-phosphate dehydrogenase (G6PD) deficiency, red blood cell breakdown may occur. It has not been studied in pregnancy. While its mechanism of action is not fully understood, its covalent binding to trypanothione to form the toxic Mel T complex is thought to play a large role. Melarsoprol has been used medically since 1949. It is on the World Health Organization's List of Essential Medicines. In regions of the world where the disease is common, melarsoprol is provided for free by the World Health Organization. It is not commercially available in Canada or the United States. In the United States, it may be obtained from the Centers for Disease Control and Prevention, while in Canada it is available from Health Canada.
Some analyses of traditional preparations of San Pedro cactus have found doses ranging from 34 mg to 159 mg of total alkaloids, a relatively low and barely psychoactive amount. It appears that patients who receive traditional treatments with San Pedro ingest sub-psychoactive doses and do not experience psychedelic effects. The onset of the effects of mescaline given orally is 0.5 to 0.9 hours on average with a range of 0.1 to 2.7 hours. Its effects peak after 1.9 to 4.0 hours with a range of 0.5 to 8.0 hours. The duration of mescaline appears to be dose-dependent, varying from 6.4 hours on average (range 3.0–10 hours) at a dose of 100 mg, 9.7 to 11 hours on average (range 5.6–22 hours) at moderate doses of 300 to 500 mg, and 14 hours on average (range 7.2–22 hours) at a dose of 800 mg. Cases of mescaline having unusually prolonged or delayed effects have also been described. Given intravenously, mescaline has been reported to have an onset of several minutes or within 10 minutes, a time to peak of 1 to 2 hours, and a duration of approximately 4 to 9 hours in different studies. Mescaline induces a psychedelic state comparable to those produced by LSD and psilocybin, but with unique characteristics. Subjective effects may include altered thinking processes, an altered sense of time and self-awareness, and closed- and open-eye visual phenomena. In PiHKAL, Shulgin described the effects of mescaline based on a collection of experience reports.
=== 2-D liquid chromatography === By coupling liquid chromatography with a variety of other immunodetection techniques such as serological proteome analysis (SERPA), it is possible to analyze the hydrophobicity, PI, relative mass, and antibody reactivity of antibodies within a given serum.
Sources: en.wikipedia.org
=== Cell culture === One of the key advantages of droplet-based microfluidics is the ability to use droplets as incubators for single cells. In addition, droplets can be applied for studies on embryogenesis of animals and plants. Devices capable of generating thousands of droplets per second open new ways to characterize cell populations, not only based on a specific marker measured at a specific time point but also based on cells' kinetic behavior such as protein secretion, enzyme activity or proliferation. Recently, a method was found to generate a stationary array of microscopic droplets for single-cell incubation that does not require the use of a surfactant.
ATP + Creatine → H+ + ADP + CP (Mg2+ assisted, catalyzed by creatine kinase) ADP + Pi → ATP (during anaerobic glycolysis and oxidative phosphorylation) AMP can dephosphorylate to adenosine and diffuse out of the cell; the purine nucleotide cycle may therefore also reduce the loss of adenosine from the cell since nucleosides permeate cell membranes, whereas nucleotides do not.
== Further reading == Schaefer, Charles (1999). "'Selling at a Wash:' Competition and the Indian Merchant Community in Aden Crown Colony". Comparative Studies of South Asia, Africa and the Middle East. 19 (2): 16–23. doi:10.1215/1089201X-19-2-16.
This has been proven in two cases in the United States in the 1980s where a couple of men's vasa deferentia were directly surgically attached to their efferent ducts and these men both subsequently impregnated their partners within the next couple of years. This has also been proven in a similar case in Western Europe in the early 1990s.
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 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.