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 2025-07-26. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
The mechanism of action involves binding to REV-ERB receptors and recruiting corepressor complexes, which represses target gene transcription. This contrasts with many nuclear receptor agonists that activate transcription. Downstream effects may include changes in autophagy, mitochondrial biogenesis, and lipid handling, but the precise pathways remain an active area of study. Whether these molecular events translate into meaningful physiological effects in humans is unresolved. Most evidence comes from cultured cells and rodent models rather than human participants.
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.
| 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 |
Regulatory treatment of SR9009 varies by country and region. It is not approved as a pharmaceutical, and several jurisdictions restrict its sale for human consumption. Some authorities classify it as a research chemical, a prescription-only substance, or a prohibited performance-enhancing agent in sport. Purchasers may encounter certificates of analysis, but these documents do not guarantee identity, purity, or legality. In research settings, institutional safety reviews and controlled procurement help ensure that materials are handled under appropriate oversight. The absence of harmonized rules means that legal status can change and requires verification.
Analytical identification of SR9009 typically relies on liquid chromatography coupled with tandem mass spectrometry. In biological samples, researchers first separate the compound from matrix components using protein precipitation, liquid-liquid extraction, or solid-phase extraction. High-performance liquid chromatography with ultraviolet detection and nuclear magnetic resonance spectroscopy can support structural confirmation of reference materials. Because SR9009 is a small, relatively lipophilic molecule, reverse-phase columns and acidic mobile phases are common. Laboratories often include isotope-labeled internal standards to improve quantification and to correct for ion suppression.
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.
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.
Laboratory samples of SR9009 are typically handled as research chemicals rather than pharmaceuticals. Suppliers usually state that the material is for research use only and not for human or veterinary administration. Storage recommendations generally call for a freezer at approximately −20 °C, protection from light, and a desiccated environment. The solid is often described as a white to off-white powder. Solubility is commonly reported in organic solvents such as dimethyl sulfoxide and ethanol, with low solubility in water.
The Gβγ sub-unit binds to the intracellular loop between the two trans-membrane helices of the VDCC. When the sub-unit binds to the voltage-dependent calcium channel, it produces a voltage-dependent block, which inhibits the channel, preventing the flow of calcium ions into the neuron. Embedded in the cell membrane is also the G protein-coupled inwardly-rectifying potassium channel. When a Gβγ or Gα(GTP) molecule binds to the C-terminus of the potassium channel, it becomes active, and potassium ions are pumped out of the neuron. The activation of the potassium channel and subsequent deactivation of the calcium channel causes membrane hyperpolarization. This is when there is a change in the membrane's potential, so that it becomes more negative. The reduction in calcium ions causes a reduction of neurotransmitter release because calcium is essential for this event to occur. This means that neurotransmitters such as glutamate and substance P cannot be released from the presynaptic terminal of the neurons. Substance P is a believed to help sensitize postsynaptic neurons to glutamate, aiding in the transmission of pain signals from periphery nerves to the brain. These neurotransmitters are vital in the transmission of pain, and as β-Endorphin reduces the release of these substances, there is a strong analgesic effect.
additive (the result is simply the expected effect of each drug taken independently), synergistic (combining the drugs leads to a larger effect than expected), or antagonistic (combining the drugs leads to a smaller effect than expected). It may be difficult to distinguish between synergistic or additive interactions, as individual effects of drugs may vary. Direct interactions between drugs are also possible and may occur when two drugs are mixed before intravenous injection. For example, mixing thiopentone and suxamethonium can lead to the precipitation of thiopentone.
Hemoglobin is also found in other cells, including in the A9 dopaminergic neurons of the substantia nigra, macrophages, alveolar cells, lungs, retinal pigment epithelium, hepatocytes, mesangial cells of the kidney, endometrial cells, cervical cells, and vaginal epithelial cells. In these tissues, hemoglobin absorbs unneeded oxygen as an antioxidant, and regulates iron metabolism. Excessive glucose in the blood can attach to hemoglobin and raise the level of hemoglobin A1c. Hemoglobin and hemoglobin-like molecules are also found in many invertebrates, fungi, and plants. In these organisms, hemoglobins may carry oxygen, or they may transport and regulate other small molecules and ions such as carbon dioxide, nitric oxide, hydrogen sulfide and sulfide. A variant called leghemoglobin serves to scavenge oxygen away from anaerobic systems such as the nitrogen-fixing nodules of leguminous plants, preventing oxygen poisoning. The medical condition hemoglobinemia, a form of anemia, is caused by intravascular hemolysis, in which hemoglobin leaks from red blood cells into the blood plasma.
This album cover... I like to refer to it as "revenge". The song 'Dirt' was written to a certain person who basically buried my ass, so the woman on the album cover is kinda the portrayal of that person being sucked down into the dirt (laughs), instead of me. The picture is the spitting image of her, and that wasn't even planned. Actually, I was pretty angry about it when I first saw it – she's not happy about it either (laughs). It was real eerie. The cover was referenced on the music video for Alice in Chains' 2009 single "A Looking in View". At the 6:55 mark of the video, a woman (played by Sacha Senisch) is seen lying on a cracked desert floor similarly to Dirt's cover. "A Looking in View" was featured on Alice in Chains' fourth studio album, Black Gives Way to Blue, released exactly 17 years after Dirt, on September 29, 2009.
Chlorphenamine (CP, CPM), also known as chlorpheniramine, is an antihistamine used to treat the symptoms of allergic conditions such as allergic rhinitis (hay fever). It is taken orally (by mouth). The medication takes effect within two hours and lasts for about 4–6 hours. It is a first-generation antihistamine and works by blocking the histamine H1 receptor. Common side effects include sleepiness, restlessness, and weakness. Other side effects may include dry mouth and wheeziness. Chlorpheniramine was patented in 1948 and came into medical use in 1949. It is available as a generic medication and over the counter. In 2023, it was the 318th most commonly prescribed medication in the United States, with more than 200,000 prescriptions.
Sources: en.wikipedia.org
Opportunistic pathogens can cause an infectious disease in a host with depressed resistance (immunodeficiency) or if they have unusual access to the inside of the body (for example, via trauma). Opportunistic infection may be caused by microbes ordinarily in contact with the host, such as pathogenic bacteria or fungi in the gastrointestinal or the upper respiratory tract, and they may also result from (otherwise innocuous) microbes acquired from other hosts (as in Clostridioides difficile colitis) or from the environment as a result of traumatic introduction (as in surgical wound infections or compound fractures). An opportunistic disease requires impairment of host defenses, which may occur as a result of genetic defects (such as chronic granulomatous disease), exposure to antimicrobial drugs or immunosuppressive chemicals (as might occur following poisoning or cancer chemotherapy), exposure to ionizing radiation, or as a result of an infectious disease with immunosuppressive activity (such as with measles, malaria or HIV disease). Primary pathogens may also cause more severe disease in a host with depressed resistance than would normally occur in an immunosufficient host.
=== Labour Party === In 1965, Hitchens joined the Labour Party on the very first day he was eligible to vote, but along with the majority of the Labour students' organization was expelled in 1967, because of what Hitchens called "Prime Minister Harold Wilson's contemptible support for the war in Vietnam". Since then he stated he had "re-enlisted a few times" back into the Labour Party. In a 2001 interview with Reason, he said that, in 1979, despite being a member of the Labour Party, he wasn't going to vote for them, nor could he bring himself to "vote Conservative." He abstained from voting. Hitchens stated that by not voting for the Labour Party he was effectively voting for Margaret Thatcher to win, which he said he had "secretly hoped would happen." In a 2005 Vanity Fair article, he endorsed Tony Blair in the 2005 general election, mainly due to his support for the 2003 invasion of Iraq. In a 2009 Slate article, he described that in the late 1970s the Labour Party moved to the right and stated that the downfall of the Labour Party came about upon Gordon Brown's becoming Prime Minister.
– indicates that no information is available As a result of heparin's effect on such a wide variety of disease states, a number of drugs are indeed in development whose molecular structures are identical or similar to those found within parts of the polymeric heparin chain.
R-30490 (also known as 4-methoxymethylfentanyl) is an opioid analgesic related to the highly potent animal tranquilizer carfentanil, and with only slightly lower potency. It was first synthesised by a team of chemists at Janssen Pharmaceutica led by Paul Janssen, who were investigating the structure-activity relationships of the fentanyl family of drugs. R-30490 was found to be the most selective agonist for the μ-opioid receptor out of all the fentanyl analogues tested, but it has never been introduced for medical use in humans, although the closely related drug sufentanil is widely used for analgesia and anesthesia during major surgery. Side effects of fentanyl analogs are similar to those of fentanyl itself, which include itching, nausea and potentially serious respiratory depression, which can be life-threatening. Fentanyl analogs have killed hundreds of people throughout Europe and the former Soviet republics since the most recent resurgence in use began in Estonia in the early 2000s, and novel derivatives continue to appear.
Distribution in pharmacology is a branch of pharmacokinetics which describes the reversible transfer of a drug from one location to another within the body. Once a drug enters into systemic circulation by absorption or direct administration, it must be distributed into interstitial and intracellular fluids. Each organ or tissue can receive different doses of the drug and the drug can remain in the different organs or tissues for a varying amount of time. The distribution of a drug between tissues is dependent on vascular permeability, regional blood flow, cardiac output and perfusion rate of the tissue and the ability of the drug to bind tissue and plasma proteins and its lipid solubility. pH partition plays a major role as well. The drug is easily distributed in highly perfused organs such as the liver, heart and kidney. It is distributed in small quantities through less perfused tissues like muscle, fat and peripheral organs. The drug can be moved from the plasma to the tissue until the equilibrium is established (for unbound drug present in plasma). The concept of compartmentalization of an organism must be considered when discussing a drug's distribution. This concept is used in pharmacokinetic modelling.
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.
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.