This is a working overview of LC-MS/MS, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-08-24. Anything still debated is marked as such rather than presented as settled.
Research interest in SR9009 grew from studies showing improved running endurance in mice after short treatment periods. Those experiments linked the compound to increased mitochondrial content and fatty acid oxidation in muscle, but the findings come from animal models and specific dosing schedules. Independent replication has been limited, and the pathways connecting REV-ERB activation to exercise performance are still being mapped. Whether similar responses occur in humans is an open question.
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.
Regulatory and sporting contexts treat SR9009 as a prohibited substance in many elite competitions. Its presence on banned lists reflects concerns about performance enhancement and unknown long-term safety. Analytical chemists have developed methods to detect the parent compound and its metabolites in urine and blood. Literature discussions distinguish between in vitro potency, animal pharmacology, and anecdotal human reports. The latter are difficult to verify because products sold online may lack purity or contain different compounds.
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.
| 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 |
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.
In laboratory settings, SR9009 is typically characterized by liquid chromatography–mass spectrometry (LC-MS) or high-performance liquid chromatography with ultraviolet detection (HPLC-UV). These methods can confirm identity and estimate purity, but they require reference standards for accurate quantification. Because SR9009 is not a licensed pharmaceutical, no harmonized pharmacopeial monograph exists. Laboratories often validate in-house methods for matrices such as plasma, urine, or cell culture media. Sample preparation may involve protein precipitation or liquid-liquid extraction before analysis.
Physicochemical behavior influences handling. SR9009 is described as a solid with limited aqueous solubility, so organic solvents such as dimethyl sulfoxide or ethanol are common in research stock solutions. Aqueous dilution can produce precipitates if the organic content is too low. Light, heat, and repeated freeze-thaw cycles may affect stability. Storage recommendations usually specify a desiccated freezer environment protected from light, but exact stability data depend on the formulation and matrix.
== Examples == Pexelizumab, a scFv binding to component 5 of the complement system and designed to reduce side effects of cardiac surgery C6.5, a diabody targeting HER2/neu found in some breast cancers Brolucizumab, a scFV binding to VEGF-A and used to treat wet age-related macular degeneration G6A, a scFV binding to human Hsp70.1 and can be used to target this protein as a potential marker in vast cancers.
=== Radiologic and pathologic features === MRI shows increased T2 signal in the lateral putamen with caudate atrophy and secondary lateral ventricular dilation. Necropsy shows loss of neurons and gliosis in the caudate and globus pallidus. Similar changes may also be seen in the thalamus, substantia nigra, and putamen. The cerebellum and cerebral cortex are generally spared.
The earliest forms of cigarettes were similar to their predecessor, the cigar. Cigarettes appear to have had antecedents in Mexico and Central America around the 9th century in the form of reeds and smoking tubes. The Maya, and later the Aztecs, smoked tobacco and other psychoactive drugs in religious rituals and frequently depicted priests and deities smoking on pottery and temple engravings. The cigarette and the cigar were the most common methods of smoking in the Caribbean, Mexico, and Central and South America until recent times. The North American, Central American, and South American cigarette used various plant wrappers; when it was brought back to Spain, maize wrappers were introduced, and by the 17th century, fine paper. The resulting product was called papelate and is documented in Goya's paintings La Cometa, La Merienda en el Manzanares, and El juego de la pelota a pala (18th century). By 1830 the cigarette had become known in France, where it received the name cigarette, and in 1845 the French state tobacco monopoly began manufacturing them. The French word made its way into English in the 1840s. Some American reformers promoted the spelling cigaret, but this was never widespread and is now largely abandoned. The first patented cigarette-making machine was invented by Juan Nepomuceno Adorno of Mexico in 1847. In the 1850s, Turkish cigarette leaves became popular.
== Metal catalysts == Metals such as iron, copper, chromium, vanadium, and cobalt are capable of redox cycling in which a single electron may be accepted or donated by the metal. This action catalyzes production of reactive radicals and reactive oxygen species. The presence of such metals in biological systems in an uncomplexed form (not in a protein or other protective metal complex) can significantly increase the level of oxidative stress. These metals are thought to induce Fenton reactions and the Haber-Weiss reaction, in which hydroxyl radical is generated from hydrogen peroxide. The hydroxyl radical then can modify amino acids. For example, meta-tyrosine and ortho-tyrosine form by hydroxylation of phenylalanine. Other reactions include lipid peroxidation and oxidation of nucleobases. Metal-catalyzed oxidations also lead to irreversible modification of arginine, lysine, proline, and threonine. Excessive oxidative-damage leads to protein degradation or aggregation. The reaction of transition metals with proteins oxidized by reactive oxygen or nitrogen species can yield reactive products that accumulate and contribute to aging and disease. For example, in Alzheimer's patients, peroxidized lipids and proteins accumulate in lysosomes of the brain cells.
== Reception == Ron Charles of The Washington Post praises Demon Copperhead as his "favorite novel of 2022" as it is "equal parts hilarious and heartbreaking, this is the story of an irrepressible boy nobody wants, but readers will love." Writing for The Guardian, Elizabeth Lowry contends that "while the task of modernising [Dickens's] novel is complicated by the fact that mores have shifted so radically since the mid-19th century … the ferocious critique of institutional poverty and its damaging effects on children is as pertinent as ever." In a starred review, Kirkus Reviews called the novel "An angry, powerful book seething with love and outrage for a community too often stereotyped or ignored."
Sources: en.wikipedia.org
== Advantages == No risk for infections Antigen presentation by both MHC class I and class II molecules Polarise T-cell response toward type 1 or type 2 Immune response focused on the antigen of interest Ease of development and production Stability for storage and shipping Cost-effectiveness Obviates need for peptide synthesis, expression and purification of recombinant proteins and use of toxic adjuvants Long-term persistence of immunogen In vivo expression ensures protein more closely resembles normal eukaryotic structure, with accompanying post-translational modifications
=== Ambient ionization mass spectrometry for disease diagnosis === The MasSpec Pen technology is based on the principles of ambient ionization, in which ions are generated directly from a sample without need for extensive sample preparation or chromatographic separations. The MasSpec Pen can further be categorized as a solid-liquid extraction based ambient ionization method, described as methods that utilize a solvent system to gently extract molecules from a sample surface that are subsequently analyzed by a mass spectrometer. Desorption electrospray ionization (DESI) was the first liquid-based ambient ionization MS method. DESI employed a spray of charged solvent droplets to bombard a sample surface to desorb and ionize molecules from the sample surface, which are then directed towards and analyzed by a mass spectrometer. DESI-MS and other solvent-based ambient ionization MS methods has been widely employed for the analysis of small molecules, primarily metabolites and lipids, directly from biological tissue specimens to determine their molecular composition and leverage the mass spectral data acquired for diagnostic purposes. These methods have been deployed for the discrimination of normal and cancerous regions of tissue samples for many solid tumor indications, including breast, brain, prostate, ovarian, and colorectal, among others. Multivariate statistical analysis methods are often utilized to generate statistical models from the mass spectral data acquired from direct analysis of tissue samples to distinguish between healthy and diseased tissues.
Its branching ratio relative to alpha decay is expected to increase with atomic number such that it may compete with alpha decay around Z = 120, and perhaps become the dominant decay mode for heavier nuclides around Z = 124. As such, it is expected to play a larger role beyond the center of the island of stability (though still influenced by shell effects), unless the center of the island lies at a higher atomic number than predicted.
=== Sites for infusion sets === Infusion sets are most commonly placed on the abdomen, in a roughly semicircular area around and below the navel. Other sites include the upper leg, upper buttocks, hips, upper arms and lower back. Insulin absorption may vary from site to site, and therefore medical advice is required.
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 small molecule studied as an agonist of the REV-ERB nuclear receptors. It is not an approved medicine, and its effects in humans are not well characterized.