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.
Last reviewed on 2025-11-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| 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 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.
Handling recommendations for SR9009 in a laboratory setting include storing the solid at low temperature, protected from light and moisture. The compound is often dissolved in dimethyl sulfoxide or ethanol for experiments. Solutions should be prepared with appropriate personal protective equipment and disposed of according to local rules. Stability data for long-term storage are limited, so stock solutions are typically kept cold and used within defined periods. Records of preparation date and concentration support reproducibility.
SR9009 is not approved as a medicine by major regulatory agencies. It is commonly sold as a research chemical, a category that may fall outside customary drug approval and quality rules. In sports, the World Anti-Doping Agency lists SR9009 as a prohibited substance. Athletes who use it can face sanctions if it is detected in a sample. Legal status varies by country, and importation may be restricted. Enforcement practices differ across borders.
Detection of SR9009 in biological samples usually employs liquid chromatography coupled with tandem mass spectrometry. This method can identify the parent compound and sometimes metabolites in urine or blood. Because exposure can be low and clearance may be rapid, sample timing and limits of detection matter. Laboratories validate assays for sensitivity and specificity. Results are interpreted alongside chain-of-custody and quality-control records. Urine is the common matrix for anti-doping analysis, while blood may be used in research settings.
Scientific discussion of SR9009 often separates animal evidence from human anecdote. Rodent studies provide controlled data on endurance, metabolism, and gene expression, but they use specific strains, doses, and treatment durations. Human reports are mostly uncontrolled and cannot establish cause and effect. Open questions include oral bioavailability, tissue distribution, metabolic stability, and long-term effects. Review articles generally call for more rigorous pharmacokinetic and safety research before any clinical use could be considered.
Analytical methods for SR9009 typically rely on liquid chromatography coupled with tandem mass spectrometry. The technique can separate the parent compound from related substances and detect low concentrations in biological matrices. Urine and blood are common samples in anti-doping testing, while in vitro studies may use cell culture media. Rapid metabolism and low expected concentrations make method validation important for reliable identification. Exact metabolite patterns can vary by species and are not fully mapped.
In early 1902, British tactics of containment, denial, and harassment finally began to yield results against the Boer guerrillas. The sourcing and co-ordination of intelligence became increasingly efficient with regular reporting from observers in the blockhouses, from units patrolling the fences and conducting "sweeper" operations, and from native Africans in rural areas who increasingly supplied intelligence, as the Scorched Earth policy took effect and they found themselves competing with the Boers for food supplies. Kitchener's forces at last began to affect the Boers' fighting strength and freedom of manoeuvre, and made it harder for the Boers and their families to survive. Despite this success, almost half the Boer fighting strength, around 15,000 men, were still in the field fighting by May 1902. However, Kitchener's tactics were costly: Britain was running out of time, patience, and money needed for the war. The British offered terms of peace on various occasions, notably in March 1901, but all them were rejected by Botha and the "Bitter-enders" among the Boers, who pledged to fight until the bitter end and rejected the demand for surrender or any compromise made by the "Hands-uppers". Their reasons included their hatred of the British, loyalty to their dead comrades, solidarity with fellow Boer commandos, a desire for independence, religious arguments, and fear of captivity or punishment. On the other hand, their women and children were dying in prison camps every day, and independence seemed more and more impossible.
=== Flexible linkers === Disordered regions are often found as flexible linkers or loops connecting domains. Linker sequences vary greatly in length but are typically rich in polar uncharged amino acids. Flexible linkers allow the connecting domains to freely twist and rotate to recruit their binding partners via protein domain dynamics. They also allow their binding partners to induce larger scale conformational changes by long-range allostery. The flexible linker of FBP25 which connects two domains of FKBP25 is important for the binding of FKBP25 with DNA.
===== Asia ===== Israel - DMT is an illegal substance; production, trade, and possession are prosecuted as crimes. India - DMT is illegal to produce, transport, trade in, or possess with a minimum prison or jail punishment of ten years.
Sources: en.wikipedia.org
From March through July 2020, vitamin C was the subject of more US FDA warning letters than any other ingredient for claims for prevention and/or treatment of COVID-19. In April 2021, the US National Institutes of Health (NIH) COVID-19 Treatment Guidelines stated that "there are insufficient data to recommend either for or against the use of vitamin C for the prevention or treatment of COVID-19." In an update posted December 2022, the NIH position was unchanged:
Generalized depression: Generalized depression is seen in the early stages of glaucoma and many other conditions. Mild constriction of the central and peripheral visual field due to isopter contraction comes under generalized depression. If all the isopters show similar depression to the same point, it is then called a contraction of the visual field. Relative paracentral scotomas are the areas where smaller and dimmer targets are not visualized by the patient. Larger and brighter targets can be seen. Small paracentral depressions, mainly superonasal are seen in normal tension glaucoma (NTG). The generalized depression of the entire field may be seen in cataract also. Baring of blind spot: "Baring of blind spot" means exclusion of blind spot from the central field due to the inward curve of the outer boundary of 30° central field. It is only an early non-specific visual field change, without much diagnostic value in glaucoma. Small wing-shaped Paracentral scotoma: Small wing-shaped Paracentral scotoma within Bjerrum's area is the earliest clinically significant field defect seen in glaucoma. It may also be associated with nasal steps. Scotoma may be seen above or below the blind spot. Siedel's sickle-shaped scotoma: Paracentral scotoma joins with the blind spot to form the Seidel sign. Arcuate or Bjerrum's scotoma: It is formed at later stages of glaucoma by extension of Seidel's scotoma in an area either above or below the fixation point to reach the horizontal line. Peripheral breakthrough may occur due to damage to nerve fibers.
==== Type II ==== Collagen is fatally defective at its C-terminus. Most cases result in death shortly after birth, or within the first year of life, due to respiratory failure. Another common cause of death is intracranial bleeds from skull fractures present at, or sustained during or shortly after, birth. In many cases, the newborn already has multiple broken bones at the time of birth. Type II infants also exhibit severe respiratory problems and have severely deformed bones. Sixty percent of infants die less than 24 hours after being born, and survival after the first year is extremely unlikely and normally requires mechanical ventilation. In the rare cases of infants who survive their first year of life, severe developmental and motor delays are seen; neither of two infants studied in 2019, both aged around two years, had achieved head control, and both required a ventilator to breathe. Type II is also known as the "lethal perinatal" form of OI, and is not compatible with survival into adulthood. Due to similarly severely deformed bones, sometimes infants with severe type III are wrongly initially classified as type II; once long-term survival is shown, they are considered as having type III instead.
=== Chemistry === Like the other noble gases, krypton is chemically highly unreactive. The rather restricted chemistry of krypton in the +2 oxidation state parallels that of the neighboring element bromine in the +1 oxidation state; due to the scandide contraction it is difficult to oxidize the 4p elements to their group oxidation states. Until the 1960s no noble gas compounds had been synthesized. Following the first successful synthesis of xenon compounds in 1962, synthesis of krypton difluoride (KrF2) was reported in 1963. In the same year, KrF4 was reported by Grosse, et al., but was subsequently shown to be a mistaken identification. Under extreme conditions, krypton reacts with fluorine to form KrF2 according to the following equation:
Sources: en.wikipedia.org
== Impact on function == Conservative replacements in proteins often have a better effect on function than non-conservative replacements. The reduced effect of conservative replacements on function can also be seen in the occurrence of different replacements in nature. Non-conservative replacements between proteins are far more likely to be removed by natural selection due to their deleterious effects.
A total of 94 F4U-7s were built for the Aéronavale in 1952, with the last of the batch, the final Corsair built, rolled out in December 1952. The F4U-7s were actually purchased by the U.S. Navy and passed on to the Aéronavale through the U.S. Military Assistance Program (MAP). They were supplemented by 25 ex-U.S.MC AU-1s (previously used in the Korean War) and moved from Yokosuka, Japan, to Tourane Air Base (Da Nang), Vietnam, in April 1952. US Air Force assistance followed in November 1953 when the French commander in Indochina, General Henri Navarre, asked General Chester E. McCarty, commander of the Combat Cargo Division, for 12 Fairchild C-119s for Operation Castor at Dien Bien Phu. The USAF also provided C-124 Globemasters to transport French paratroop reinforcements to Indochina. Under the codename Project Swivel Chair, on March 3, 1954, 12 C-119s of the 483rd Troop Carrier Wing ("Packet Rats") based at Ashiya, Japan, were painted with France's insignia and loaned to France with 24 CIA pilots for short-term use. Maintenance was carried out by the US Air Force and airlift operations were commanded by McCarty.
Transformation of a bacterial host with two different plasmids is required. One is designed to express a DNA-binding protein-of-interest as a fusion construct with a subunit of RNA polymerase (bait). The other plasmid contains a region of randomized sequence representing potential binding sites (prey) which, if bound to by the chimeric fusion product, drives expression of downstream reporter genes. This reporter region facilitates both positive and negative selection by HIS3 and URA3, respectively, which together allow for isolation of the prey containing the true DNA target sequence. HIS3 and URA3 encode proteins required for biosynthesis of histidine and uracil. Using a negative selectable marker is crucial for greatly reducing the incidence of false-positives. Self-activating prey, where the randomized region facilitate reporter expression in the absence of TF binding, are removed by transforming the reporter vector library into bacteria in the absence of bait and assaying for growth on plates containing 5-fluoro-orotic acid (5-FOA). The protein product of URA3 converts 5-FOA into a toxic compound, thereby allowing survival of only those colonies that contain reporter vectors which are not self-activating. Negative selection normally precedes positive selection so that a smaller, purified prey library can be subjected to the more rigorous positive selection process. Upon transformation of the purified prey library with the bait plasmid, positive selection is achieved by growing the host E.
== Analytical methods == Given the large diversity of PFAS structures that exist, analytical methods for PFAS analysis generally take one of two different approaches: targeted analysis or non-targeted analysis. Targeted methods narrow focus on known PFAS of concern (e.g. PFOA, PFOS) and generally use solid-phase extraction with liquid chromatography–mass spectrometry (LC-MS) detection. For example, EPA Method 537.1 is approved for use in drinking water and can quantify 18 PFAS compounds, while EPA Method 1633A is approved for use for wastewater, surface water, groundwater, soil, biosolids, sediment, landfill leachate, and fish tissue for 40 PFAS chemicals. Regulatory limits for PFOA and PFOS set by the US EPA (4 parts-per-trillion) are limited by the capability of targeted methods to detect low-level concentrations. Non-targeted analyses often sacrifice the identification and quantification of specific PFAS compounds to better understand the amount of PFAS present as a class. For example, total organic fluorine (TOF) analysis quantifies the amount of fluoride produced when a sample is oxidized at high enough temperatures to break the carbon-fluorine bond using combustion ion chromatography. Variants of this analysis include adsorbable organic fluorine (AOF) and extractable organic fluorine (EOF), which use similar solid-phase extraction approaches as the targeted analysis, but use combustion ion chromatography (CIC) as a detector.
One person was killed in a Russian missile attack in Sumy Oblast. Russian officials claimed that drones struck energy facilities in Rostov and Voronezh Oblasts. HUR officials claimed that two Su-34s were damaged during a Ukrainian drone strike on the Morozovsk air base in Rostov Oblast, with unconfirmed reports of six pilots killed and 10 troops wounded. Russian President Vladimir Putin claimed that almost 700,000 Russian soldiers were fighting in Ukraine, as on 14 June. The Ukrainian 68th Jaeger Brigade claimed to have destroyed an entire Russian tank company, with eight tanks destroyed and two damaged, plus eight infantry fighting vehicles and two artillery pieces destroyed in the Pokrovsk sector. They also claimed that 242 Russian troops were killed or wounded during fighting in the Pokrovsk direction on 14 June. Russia designated the Georgian National Legion, a foreign volunteer unit fighting for Ukraine, as a terrorist organisation. South Korean Defense Minister Shin Won-sik claimed that North Korea could have sent 4.8 million rounds of artillery ammunition to Russia, for use in Ukraine, as well as "dozens" of ballistic missiles.
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.
It is a synthetic compound that acts as an agonist at REV-ERBα and REV-ERBβ. It is used mainly as a research chemical to study circadian and metabolic pathways. It is not approved for human therapeutic use.