LC-MS is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-04-12. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| 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 |
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.
== Subtypes == Based on receptor binding studies, three variants of the KOR: κ1, κ2, and κ3 have been characterized via radioligand binding and regional CNS mapping. However, only one encoding cDNA has been cloned, hence these subtypes likely arise from interactions of the KOR protein with other membrane-associated proteins rather than gene duplication. Historically the understanding that KORs are encoded by a single gene reopened the question of how one receptor system could be involved in such a multiplicity of interactions and disparate profiles.
Equilin is a naturally occurring estrogen sex hormone found in horses as well as a medication. It is one of the estrogens present in the estrogen combination drug preparations known as conjugated estrogens (CEEs; e.g. Premarin) and esterified estrogens (EEs; e.g. Estratab, Menest). CEEs is the most commonly used form of estrogen medications in hormone replacement therapy (HRT) for menopausal symptoms in the United States. Estrone sulfate is the major estrogen in CEEs (about 50%) while equilin sulfate is the second major estrogen in the formulation, present as about 25% of the total.
=== Direct collection === A thick portion of sea ice is partially drilled into to create a hole that is covered and left to accumulate draining brine at the bottom before being collected later. This brine drainage occurs much more slowly as temperatures decrease, especially below –5 °C, which is the limit for bulk ice permeability. One limitation to this method is that the origins of the drained brine, as well as what proportion of microbes were left behind in the brine pool, cannot be known with certainty. Studies on these "sackhole" brines have illustrated that substantial bacteria and viruses can be found within brine pools.
=== Supercritical desalination === The solubility of dissolved ions drops precipitously once a fluid becomes supercritical. This effect can be used to precipitate salts from high salinity desalination streams, with solubility of different salts decreasing rapidly as water approaches supercritical temperatures. Complex cycle design can enable selective precipitation and improved heat recovery. Some very saline water sources like produced water also have high hydrocarbon content, which can be oxidized by supercritical desalination.
=== Complications === Anorexia nervosa can have serious implications if its duration and severity are significant and if onset occurs before the completion of growth, pubertal maturation, or the attainment of peak bone mass. Complications specific to adolescents and children with anorexia nervosa can include growth retardation, as height gain may slow and can stop completely with severe weight loss or chronic malnutrition. In such cases, provided that growth potential is preserved, height increase can resume and reach full potential after normal intake is resumed. Height potential is normally preserved if the duration and severity of illness are not significant or if the illness is accompanied by delayed bone age (especially prior to a bone age of approximately 15 years), as hypogonadism may partially counteract the effects of undernutrition on height by allowing for a longer duration of growth compared to controls. Appropriate early treatment can preserve height potential, and may even help to increase it in some post-anorexic subjects, due to factors such as long-term reduced estrogen-producing adipose tissue levels compared to premorbid levels. In some cases, especially where onset is before puberty, complications such as stunted growth and pubertal delay are usually reversible. Anorexia nervosa causes alterations in the female reproductive system; significant weight loss, as well as psychological stress and intense exercise, typically results in a cessation of menstruation in women who are past puberty.
Sources: en.wikipedia.org
Ningxia Provincial Government Archived 15 April 2012 at the Wayback Machine Ningxia at the Encyclopædia Britannica Economic profile for Ningxia at HKTDC Ningxia Profile – UNESCAP Archived 16 January 2014 at the Wayback Machine Ningxia Profile – China Economic Information Network
Kenneth D. Tew is a Scottish-American pharmacologist, academic and author. He is a professor in the Department of Cell & Molecular Pharmacology and the John C. West Endowed Chair in Cancer Research at the Medical University of South Carolina. Tew's research primarily focuses on identifying cancer strategies with strong translational potential, particularly in the context of redox pathways, and resistance to various drugs to understand redox mechanisms and their connections to essential signaling pathways. He has authored, co-authored and edited research articles and books such as Preclinical and Clinical Modulation of Anticancer Drugs and Basic Science of Cancer. He is the recipient of the Outstanding Investigator Grant from the National Cancer Institute in 1993, the 2003 American Cancer Society Scientific Research Award and the 2010 Astellas USA Foundation Award from the American Society for Pharmacology and Experimental Therapeutics. Tew is an Elected Fellow of the American Association for the Advancement of Science and the American Society for Pharmacology and Experimental Therapeutics. He is an Executive Editor of Biomedicine & Pharmacotherapy.
There was low- to moderate-strength evidence of no benefit for most of the other medications used in RCTs, which included antidepressants (bupropion, mirtazapine, sertraline), antipsychotics (aripiprazole), anticonvulsants (topiramate, baclofen, gabapentin), naltrexone, varenicline, citicoline, ondansetron, prometa, riluzole, atomoxetine, dextroamphetamine, and modafinil.
== Introduction == Isotopologues are molecules that have the same chemical composition, but differ only in their isotopic composition. Methane has ten stable isotopologues: 12CH4, 13CH4, 12CH3D, 13CH3D, 12CH2D2, 13CH2D2, 12CHD3, 13CHD3, 12CD4 and 13CD4, among which, 12CH4 is an unsubstituted isotopologue; 13CH4 and 12CH3D are singly substituted isotopologues; 13CH3D and 12CH2D2 are doubly substituted isotopologues. The multiple-substituted isotopologues are clumped isotopologues. The absolute abundance of each isotopologue primarily depends on the traditional carbon and hydrogen isotope compositions (δ13C and δD) of the molecules. Clumped isotope composition is calculated relative to the random distribution of carbon and hydrogen isotopes in the methane molecules. The deviations from the random distribution is the key signature of methane clumped isotope (please see "notation" for details). In thermodynamic equilibrium, methane clumped isotopologue composition has a monotonic relationship with formation temperature. This is the condition for many geological environments so that methane clumped isotope can record its formation temperature, and therefore can be used to identify the origins of methane. When methane clumped-isotope composition is controlled by kinetic effects, for example, for microbial methane, it has the potential to be used to study metabolism. The study of methane clumped isotopologues is very recent. The first mass spectrometry measurement of methane clumped isotopologues of natural abundance was made in 2014. This is a very young and fast-growing field.
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.
Liquid chromatography–mass spectrometry is common for identity and purity checks. High-performance liquid chromatography with ultraviolet detection can also be used. Both methods require a suitable reference standard.