LC-MS/MS comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-05-07. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Detection of SR9009 in biological samples usually relies on liquid chromatography coupled to tandem mass spectrometry. This approach separates the compound from matrix components and identifies it by mass transitions. Because SR9009 can undergo metabolism, laboratories often look for both parent drug and specific metabolites. Sample preparation may involve protein precipitation or solid-phase extraction. Method validation examines sensitivity, carryover, and interference from related substances, and reference standards are required for accurate calibration.
Storage recommendations for SR9009 reference material typically specify a freezer at -20 °C or lower, with protection from moisture and light. Repeated freeze-thaw cycles can degrade small molecules and introduce variability. Stock solutions in dimethyl sulfoxide are often aliquoted to avoid repeated handling. Stability studies may examine degradation under heat, humidity, and light exposure. The compound's thiophene and nitro groups can participate in reactions that alter analytical signals over time, so such changes affect quantitative results.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic small molecule | Studied as a REV-ERB agonist |
| Molecular formula | C20H24ClN3O4S | Reported for the neutral compound |
| Appearance | Off-white to pale yellow solid | Typical research-grade material |
| Solubility | Sparingly soluble in water | Soluble in solvents such as DMSO |
| Common synonyms | SR9009; Stenabolic | Stenabolic is an informal alias |
SR9009 is a synthetic small molecule studied as an agonist of REV-ERB nuclear receptors. REV-ERB alpha and REV-ERB beta help regulate circadian rhythms and metabolic gene expression. In laboratory research, SR9009 has been used to probe how these receptors affect skeletal muscle, liver, and adipose tissue. The compound was identified in academic drug-discovery work and is often described in scientific literature by its chemical name and research code. It is not an approved medicine, and human clinical data remain limited or absent.
SR9009 binds REV-ERB receptors and alters their repressive activity on target genes. This action can change transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. In rodent studies, treated animals have shown changes in muscle oxidative capacity and exercise performance, though effects vary by dose, duration, and model. The precise molecular steps connecting receptor binding to whole-body outcomes are still an active area of investigation. Findings in animals do not automatically translate to humans.
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.
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.
== Side effects == Frequently (≥1% to <10%) reported adverse reactions with opipramol, especially at the beginning of the treatment, include fatigue, dry mouth, blocked nose, hypotension, and orthostatic dysregulation. Adverse reactions reported occasionally (≥0.1% to <1%) include dizziness, stupor, micturition disturbances, vigilance, accommodation disturbances, tremor, weight gain, thirst, allergic skin reactions (rash, urticaria), abnormal ejaculation, erectile impotence, constipation, transient increases in liver enzymes, tachycardia, and palpitations. Rarely (≥0.01% to <0.1%) reported adverse reactions include excitation, headache, paresthesia especially in elderly patients, restlessness, sweating, sleep disturbances, edema, galactorrhea, urine blockage, nausea and vomiting, fever, collapse conditions, stimulation conducting disturbances, intensification of present heart insufficiency, blood profile changes particularly leukopenia, confusion, delirium, stomach complaints, taste disturbance, and paralytic ileus especially with sudden discontinuation of a longer-term high-dose therapy. Very rarely (<0.01%) reported adverse reactions include seizures, motor disorders (akathisia, dyskinesia, ataxia), polyneuropathy, glaucoma, anxiety, hair loss, agranulocytosis, severe liver dysfunction after long-term treatment, jaundice, and chronic liver damage.
== History == Gemtuzumab ozogamicin was created in a collaboration between Celltech and Wyeth that began in 1991. The same collaboration later produced inotuzumab ozogamicin. Celltech was acquired by UCB in 2004 and Wyeth was acquired by Pfizer in 2009. In the United States, gemtuzumab ozogamicin was approved under an accelerated-approval process by the FDA in 2000, for use in patients over the age of 60 with relapsed acute myelogenous leukemia (AML); or those who are not considered candidates for standard chemotherapy. The accelerated approval was based on the surrogate endpoint of response rate. It was the first antibody-drug conjugate to be approved. Within the first year after approval, the FDA required a black box warning be added to gemtuzumab packaging. The drug was noted to increase the risk of veno-occlusive disease in the absence of bone marrow transplantation. Later the onset of VOD was shown to occur at increased frequency in gemtuzumab patients even following bone marrow transplantation. The drug was discussed in a 2008 JAMA article, which criticized the inadequacy of postmarketing surveillance of biologic agents. A randomized Phase III comparative controlled trial (SWOG S0106) was initiated in 2004, by Wyeth in accordance with the FDA accelerated-approval process. The study was stopped on August 20, 2009, prior to completion due to worrisome outcomes. Among the patients evaluated for early toxicity, fatal toxicity rate was significantly higher in the gemtuzumab combination therapy group vs the standard therapy group.
Curcumin, which shows positive results in most drug discovery assays, is regarded as a false lead that medicinal chemists include among "pan-assay interference compounds". This attracts undue experimental attention while failing to advance as viable therapeutic or drug leads, although some derivatives of curcumin such as EF-24 have been well-studied. Factors that limit the bioactivity of curcumin or its analogs include chemical instability, water insolubility, absence of potent and selective target activity, low bioavailability, limited tissue distribution, and extensive metabolism. Very little curcumin escapes the GI tract and most is excreted in feces unchanged. If curcumin enters plasma in reasonable amounts, there is a high risk of toxicity since it is promiscuous, and interacts with several proteins known to increase the risk of adverse effects, including hERG, cytochrome P450s, and glutathione S-transferase.
Sources: en.wikipedia.org
Also in 2003, Freeman starred in two other dramas that were not widely seen, Levity and Guilty by Association. His 2004 releases were comedy The Big Bounce and sports drama Million Dollar Baby. In the latter, directed by Clint Eastwood, Freeman portrayed an elderly former boxer. The film won four Academy Awards, including Best Picture, Best Director, Best Actress (Hilary Swank), and Best Supporting Actor, earning Freeman his first Academy Award. Freeman was also nominated for a Golden Globe Award in the same category. Roger Ebert complimented Freeman's "flat and factual" narration, and Timeout magazine thought the cast fully inhabited their roles.
Treponema pallidum pallidum is a motile spirochete that is generally acquired by close sexual contact, entering the host via breaches in squamous or columnar epithelium. The organism can also be transmitted to a fetus by transplacental passage during the later stages of pregnancy, giving rise to congenital syphilis. The helical structure of T. p. pallidum allows it to move in a corkscrew motion through mucous membranes or enter minuscule breaks in the skin. In women, the initial lesion is usually on the labia, the walls of the vagina, or the cervix; in men, it is on the shaft or glans of the penis. It gains access to the host's blood and lymph systems through tissue and mucous membranes. In more severe cases, it may gain access to the host by infecting the skeletal bones and central nervous system of the body. Despite effective antibiotic treatment since the mid twentieth century, this infection has been emerging globally in the last few decades. In 2021, approximately 6 million new infections occurred globally. In laboratory cultures, some contemporary variants of T. p. pallidum strains have been failing to respond to the second line antibiotic azithromycin. This phylogenetic divergence and global presence point to the emergence of a pandemic strain cluster. In addition to phylogenetic divergence, the switch to confidential record keeping resulted in an overall decrease in quality of tracking and recording disease prevalence. The incubation period for a T. p. pallidum infection is usually around 21 days, but can range from 10 to 90 days.
== Research == Some related pyrrylphenylethanones had analgesic activity comparable to morphine. Some pyrrole analogues were reported to have analgesic effects comparable to lefetamine and being devoid of neurotoxic properties.
Sources: en.wikipedia.org
SR9009 is a synthetic research compound that activates the REV-ERBα and REV-ERBβ nuclear receptors. It is not an approved drug and has no established human therapeutic use. Most published biological data come from cell and rodent studies.
No. SR9009 is frequently mislabeled as a SARM in online discussions, but it does not target androgen receptors. Its known mechanism involves REV-ERB nuclear receptors and circadian-metabolic gene regulation.
Human clinical data are very limited. There is no approved human use, and safety and efficacy in people are not established. Most evidence comes from preclinical models, so effects observed in animals may not apply to humans.
Liquid chromatography-tandem mass spectrometry is a common approach. It can detect the parent compound and its metabolites in biological matrices.