The short version of LC-MS/MS fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-04-09. Anything still debated is marked as such rather than presented as settled.
Quality control for research materials includes identity confirmation by nuclear magnetic resonance and purity assessment by high-performance liquid chromatography. Mass spectrometry provides molecular weight confirmation and can detect related impurities. Purchasers should request a certificate of analysis that lists lot-specific data. Online products advertised for human use often lack such documentation. Distinguishing legitimate research material from mislabeled or contaminated samples is a recurring challenge in independent testing, and independent laboratories may use orthogonal methods to verify identity.
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.
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.
SR9009 is a synthetic small molecule developed as a REV-ERB agonist. It binds to REV-ERBα and REV-ERBβ, nuclear receptors that help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, the compound alters lipid and glucose handling and influences skeletal muscle oxidative capacity. Its exact effects in humans remain largely uncharacterized because controlled clinical trials have not been reported. The molecule is frequently described in preclinical literature as a metabolic modulator.
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.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | -20 °C or lower | Desiccated and protected from light |
| Common analytical method | LC-MS/MS | Detects parent drug and metabolites |
| Solubility class | Lipophilic; soluble in organic solvents | Low aqueous solubility |
| Molecular weight | 437.94 g/mol | Calculated from reported formula |
| Synonyms | SR9009; REV-ERB agonist | Code name used in scientific literature |
Most published work on SR9009 consists of preclinical studies. It is widely sold as a research chemical, a category that does not imply safety, efficacy, or pharmaceutical-grade quality. Sports anti-doping organizations have listed SR9009 as a prohibited substance, and its presence in an athlete sample can lead to sanctions. Legal status differs by country; in several jurisdictions it is not approved for human consumption and may be treated as an unapproved new drug.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is not a steroid, peptide, or natural hormone. In scientific literature, it appears under the code SR9009 and in non-scientific contexts as Stenabolic. The compound was identified through chemical screening efforts aimed at targeting circadian clock components. Its status remains investigational, and no regulatory agency has approved it as a human medicine.
REV-ERB proteins help regulate daily cycles in gene expression, including genes tied to lipid and glucose metabolism. SR9009 binds these receptors and alters their activity in cell and animal experiments. Consequences observed in rodents include changes in skeletal muscle oxidative capacity, blood lipid levels, and exercise performance. The precise chain from receptor occupancy to whole-body effects is still an active area of study. Human responses cannot be assumed from rodent data.
Detection in biological samples can be complicated by rapid metabolism and low circulating concentrations. Some studies report phase I and phase II metabolites, and analytical methods may need to target those species in addition to the parent compound. Immunoassays are not broadly available, so mass spectrometry remains the main confirmatory approach. For anti-doping testing, laboratories look for SR9009 and its metabolites using validated LC-MS methods. Open questions include how long metabolites remain detectable and how different routes of administration alter detection windows.
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.
SR9009 stability depends on temperature, moisture, light, and solvent. Solid material is generally kept cool and dry, while solutions may require protection from repeated warming and cooling. Degradation can appear as color changes, precipitate, or new chromatographic peaks. Researchers should follow supplier instructions and their own stability data. Long-term storage conditions for human use have not been established because the compound lacks approved clinical formulation.
SR9009 is supplied as a solid research chemical, often in milligram quantities. Laboratories typically weigh it in a controlled environment because fine powders can disperse. Stock solutions are commonly prepared in dimethyl sulfoxide and stored in small aliquots to reduce freeze-thaw cycles. Personal protective equipment and chemical fume hoods are standard when handling unknown or potent compounds. These practices address laboratory safety rather than human use.
Identity and purity of SR9009 samples are usually checked with chromatographic and spectrometric methods. High-performance liquid chromatography can separate the compound from related impurities, while mass spectrometry provides molecular mass confirmation. Nuclear magnetic resonance spectroscopy may be used for structural verification in research settings. No single method proves biological activity, and certificates of analysis should be reviewed alongside raw data. Independent testing is often needed because online products vary widely.
The idea that life originated from non-living matter in slow stages appeared in Herbert Spencer's 1864–1867 book Principles of Biology, and in William Turner Thiselton-Dyer's 1879 paper "On spontaneous generation and evolution". On 1 February 1871 Charles Darwin wrote about these publications to Joseph Hooker, and set out his own speculation that the original spark of life may have been in a "warm little pond, with all sorts of ammonia and phosphoric salts,—light, heat, electricity &c present, that a protein compound was chemically formed". Darwin explained that "at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed." Alexander Oparin in 1924 and J. B. S. Haldane in 1929 proposed that the earliest cells slowly self-organized from a primordial soup, the Oparin–Haldane hypothesis. Haldane suggested that the Earth's prebiotic oceans consisted of a "hot dilute soup" in which organic compounds could have formed. J. D. Bernal showed that such mechanisms could form most of the necessary molecules for life from inorganic precursors. In 1967, he suggested three "stages": the origin of biological monomers; the origin of biological polymers; and the evolution from molecules to cells.
=== Diet === Changes in diet may help prevent the development of atherosclerosis. Tentative evidence suggests that a diet containing dairy products has no effect on or decreases the risk of cardiovascular disease. A diet rich in fruits and vegetables lowers the risk of cardiovascular disease and death. Evidence suggests that the Mediterranean diet may improve cardiovascular results. There is also evidence that a Mediterranean diet may be better than a low-fat diet in bringing about long-term changes to cardiovascular risk factors (e.g., lower cholesterol level and blood pressure). A 2024 review highlighted that bioactive compounds found in Mediterranean diet components (such as olive, grape, garlic, rosemary, and saffron) exhibit properties that may contribute to cardiovascular health and atherosclerosis prevention.
Immunohematology is a branch of hematology and transfusion medicine which studies antigen-antibody reactions and analogous phenomena as they relate to the pathogenesis and clinical manifestations of blood disorders. A person employed in this field is referred to as an immunohematologist or colloquially as a blood banker. Their day-to-day duties include blood typing, cross-matching and antibody identification.
Intoxication can occur naturally as a result of either wound or intestinal infection or by ingesting formed toxin in food. The estimated human median lethal dose of type A toxin is 1.3–2.1 ng/kg intravenously or intramuscularly, 10–13 ng/kg when inhaled, or 1 μg/kg when taken by mouth.
== Regulation == In Arabidopsis, two chains of catalytic ALS (InterPro: IPR012846) is complexed with two regulatory small subunits (InterPro: IPR004789), AHASS2 and AHASS1. Such an arrangement is widespread in both bacterial and eukaryotic ALS. The hetromeric structure was demonstrated in E. coli in 1984 and in eukaryotes (S. cerevisiae and Porphyra purpurea) in 1997. Most of the regulatory proteins have an ACT domain (InterPro: IPR002912) and some of them have a NiKR-like C-terminal (InterPro: IPR027271) In bacteria (E. coli)), Acetolactate synthase consists of three pairs of isoforms. Each pair includes a large subunit, which is thought to be responsible for catalysis, and a small subunit for feedback inhibition. Each subunit pair, or ALS I, II, and III respectively, is located on its own operon, ilvBN, ilvGM, and ilvIH (where ilvN regulated ilvB, and vice versa). Together, these operons code for several enzymes involved in branched-chain amino acid biosynthesis. Regulation is different for each operon.
Sources: en.wikipedia.org
ρ is fluid density, t is time, u is the flow velocity vector field. The time derivative can be understood as the accumulation (or loss) of mass in the system, while the divergence term represents the difference in flow in versus flow out. In this context, this equation is also one of the Euler equations (fluid dynamics). The Navier–Stokes equations form a vector continuity equation describing the conservation of linear momentum. If the fluid is incompressible (volumetric strain rate is zero), the mass continuity equation simplifies to a volume continuity equation:
== Types == The following is a comparison of different types of prostaglandin, including prostaglandin I2 (prostacyclin; PGI2), prostaglandin D2 (PGD2), prostaglandin E2 (PGE2), and prostaglandin F2α (PGF2α).
A ligand-targeted liposome (LTL) is a nanocarrier with specific ligands attached to its surface to enhance localization for targeted drug delivery. The targeting ability of LTLs enhances cellular localization and uptake of these liposomes for therapeutic or diagnostic purposes. LTLs have the potential to enhance drug delivery by decreasing peripheral systemic toxicity, increasing in vivo drug stability, enhancing cellular uptake, and increasing efficiency for chemotherapeutics and other applications. Liposomes are beneficial in therapeutic manufacturing because of low batch-to-batch variability, easy synthesis, favorable scalability, and strong biocompatibility. Ligand-targeting technology enhances liposomes by adding targeting properties for directed drug delivery.
=== RNA in information storage === RNA is a very similar molecule to DNA, with only two significant chemical differences (the backbone of RNA uses ribose instead of deoxyribose and its nucleobases include uracil instead of thymine). The overall structure of RNA and DNA are immensely similar—one strand of DNA and one of RNA can bind to form a double helical structure. This makes the storage of information in RNA possible in a very similar way to the storage of information in DNA. However, RNA is less stable, being more prone to hydrolysis due to the presence of a hydroxyl group at the ribose 2' position.
=== Fertilizer === The chelating ability of amino acids is sometimes used in fertilizers to facilitate the delivery of minerals to plants in order to correct mineral deficiencies, such as iron chlorosis. These fertilizers are also used to prevent deficiencies from occurring and to improve the overall health of the plants.
Sources: en.wikipedia.org
== Contraindications == Contraindications include the coadministration of terfenadine, astemizole, cisapride, pimozide, or carbamazepine. Nefazodone is contraindicated in patients who were withdrawn from nefazodone because of evident liver injury as well as those that have shown hypersensitivity to the drug, its inactive ingredients, or other phenylpiperazine antidepressants. Furthermore, the coadministration of triazolam and nefazodone should be avoided for all patients, including the elderly, since it causes a significant increase in the plasma level of triazolam and not all commercially available dosage forms of triazolam permit a sufficient dosage reduction. If coadministrated, a 75% reduction in the initial dosage of triazolam is recommended.
=== Others === Blood: Pentamidine frequently causes leukopenia and less often thrombopenia, which may cause symptomatic bleeding. Some cases of anemia, possibly related to folic acid deficiency, have been described. Cardiovascular: Hypotension, which may be severe. Severe or fatal arrhythmias and heart failure are quite frequent. Kidney: 25 percent develop signs of nephrotoxicity ranging from mild, asymptomatic azotemia (increased serum creatinine and urea) to irreversible renal failure. Ample fluids or intravenous hydration may prevent some nephrotoxicity. Liver: Elevated liver enzymes are associated with intravenous use of pentamidine. Hepatomegaly and hepatitis have been encountered with long term prophylactic use of pentamidine inhalation. Neurological: Dizziness, drowsiness, neuralgia, confusion, hallucinations, seizures and other central side effects are reported. Pancreas: Hypoglycemia that requires symptomatic treatment is frequently seen. On the other hand, pentamidine may cause or worsen diabetes mellitus. Respiratory: Cough and bronchospasm, most frequently seen with inhalation. Skin: Severe local reactions after extravasculation of intravenous solutions or following intramuscular injection treatment have been seen. Pentamidine itself may cause rash, or rarely Stevens–Johnson syndrome or Lyell syndrome. Eye discomfort, conjunctivitis, throat irritation, splenomegaly, Herxheimer reaction, electrolyte imbalances (e.g. hypocalcemia).
Subsequent experiments showed that the 19 "cold" amino acids were not necessary and that the protein product had the biochemical characteristics of polyphenylalanine, demonstrating that a chain of repeated uracil bases produced a protein chain made solely of the repeating amino acid phenylalanine. While the experiment did not determine the number of bases per codon, it was consistent with the triplet codon UUU coding for phenylalanine. In analogous experiments with other synthetic RNAs, they found that poly-C directed synthesis of polyproline. Nirenberg recounts that the labs of Severo Ochoa and James Watson had earlier done similar experiments with poly-A, but failed to detect protein synthesis because polylysine (unlike most proteins) is soluble in trichloroacetic acid. Further, using synthetic RNAs that randomly incorporated two bases at different ratios, they produced proteins containing more than one type of amino acid, from which they could deduce the triplet nature of the genetic code and narrow down the codon possibilities for other amino acids. Nirenberg's group eventually decoded all the amino acid codons by 1966, however this required additional ingenious experimental methods (see Nirenberg and Leder experiment).
On 27 October 1977, a group of insurgents attacked a SADF patrol in the Cutline, killing 5 South African soldiers and mortally wounding a sixth. As military historian Willem Steenkamp records, "while not a large clash by World War II or Vietnam standards, it was a milestone in what was then...a low intensity conflict". Three months later, insurgents fired on patrols in the Cutline again, killing six more soldiers. The growing number of ambushes and infiltrations were timed to coincide with assassination attempts on prominent South West African tribal officials. Perhaps the most high-profile assassination of a tribal leader during this time was that of Herero chief Clemens Kapuuo, which South Africa blamed on PLAN. Vorster finally acquiesced to Botha's requests for retaliatory strikes against PLAN in Angola, and the SADF launched Operation Reindeer in May 1978. One controversial development of Operation Reindeer helped sour the international community on the South African Border War. On 4 May 1978, a battalion-sized task force of the 44 Parachute Brigade conducted a sweep through the Angolan mining town of Cassinga, searching for what it believed was a PLAN administrative centre.
nucleus pl. nuclei A large spherical or lobular organelle surrounded by a dedicated membrane which functions as the main storage compartment for the genetic material of eukaryotic cells, including the DNA comprising chromosomes, as well as the site of RNA synthesis during transcription. The vast majority of eukaryotic cells have a single nucleus, though some cells may have more than one nucleus, either temporarily or permanently, and in some organisms there exist certain cell types (e.g. mammalian erythrocytes) which lose their nuclei upon reaching maturity, effectively becoming anucleate. The nucleus is one of the defining features of eukaryotes; the cells of prokaryotes such as bacteria lack nuclei entirely.
Sources: en.wikipedia.org
Liquid chromatography-tandem mass spectrometry is a common approach. It can detect the parent compound and its metabolites in biological matrices.
Research samples are typically kept frozen, desiccated, and protected from light. Stock solutions are often aliquoted to reduce freeze-thaw cycles.
High-performance liquid chromatography and nuclear magnetic resonance are standard for purity and identity. Mass spectrometry confirms molecular weight.
It is a synthetic REV-ERB agonist used mainly in preclinical research. It is not an approved medicine for human use.