This is a working overview of NR1D1, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is not an approved medicine and has no established human therapeutic use. The compound appears in scientific literature as a tool for probing circadian and metabolic regulation. Online sellers often label it as a research chemical, sometimes using the nickname Stenabolic. Its chemical identity is distinct from selective androgen receptor modulators, stimulants, and peroxisome proliferator-activated receptor delta agonists. Researchers use it mainly in cell and animal experiments.
At the molecular level, SR9009 binds REV-ERBα and REV-ERBβ and alters their repressive activity on target genes. These nuclear receptors help regulate the circadian clock, lipid synthesis, glucose metabolism, and inflammatory pathways. By changing transcription, the compound can shift the timing or magnitude of downstream metabolic processes in model systems. It does not act through androgen receptors or adenosine receptors, which distinguishes it from several substances sold for athletic performance. Whether the same transcriptional changes occur in humans at tolerable exposures remains an open question because controlled human studies are lacking.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C20H24ClN3O4S | Derived from published structure. |
| Molecular weight | 437.94 g/mol | Calculated value. |
| Appearance | White to off-white solid | Typical for purified research samples. |
| Solubility | DMSO, ethanol; low in water | Class: poorly water-soluble. |
| Typical storage | -20 °C, desiccated, protected from light | Limits degradation. |
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.
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.
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.
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.
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.
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.
Regulatory treatment of SR9009 reflects its investigational status. The compound has no approved human therapeutic indication, and sports authorities prohibit its use. It appears on anti-doping lists as a non-approved substance or metabolic modulator, depending on the list version. Products sold online as research chemicals are not quality-controlled medicines, so their identity and purity can differ from the label. Such products may also contain unlisted compounds, which complicates both testing and safety assessment.
Neural connections are constantly changing within the nervous system. Synaptic connections that are used more often are kept intact and promoted, while synaptic connections that are rarely used are subject to degradation. Elevated levels of synaptic connection loss and degradation of neurons are linked to neurodegenerative diseases. More recently, ferroptosis has been linked to diverse brain diseases, in particular, Alzheimer's disease, amyotrophic lateral sclerosis (ALS), and Parkinson's disease. Two new studies show that ferroptosis contributes to neuronal death after intracerebral hemorrhage. Neurons that are degraded through ferroptosis release lipid metabolites from inside the cell body. The lipid metabolites are harmful to surrounding neurons, causing inflammation in the brain. Inflammation is a pathological feature of Alzheimer's disease and intracerebral hemorrhage. Recent studies have suggested that ferroptosis contributes to neuronal cell death after traumatic brain injury. Hypoxic brain injury in resuscitated patients shows retrospective evidence of ferroptosis. Additionally there is evidence that the prion protein and pathogenic prions PrPSc contribute to ferroptosis sensitivity in the brain, a condition that is enhanced by RAC3 expression.
Liberation – How is the active pharmaceutical ingredient disintegrated (for solid oral forms (breaking down into smaller particles), dispersed, or dissolved from the medication? Absorption – How is the active pharmaceutical ingredient absorbed (through the skin, the intestine, the oral mucosa)? Distribution – How does the active pharmaceutical ingredient spread through the organism? Metabolism – Is the active pharmaceutical ingredient converted chemically inside the body, and into which substances. Are these active (as well)? Could they be toxic? Excretion – How is the active pharmaceutical ingredient excreted (through the bile, urine, breath, skin)? Drug metabolism is assessed in pharmacokinetics and is important in drug research and prescribing. Pharmacokinetics is the movement of the drug in the body, it is usually described as 'what the body does to the drug' the physico-chemical properties of a drug will affect the rate and extent of absorption, extent of distribution, metabolism and elimination. The drug needs to have the appropriate molecular weight, polarity etc. in order to be absorbed, the fraction of a drug that reaches the systemic circulation is termed bioavailability, this is simply a ratio of the peak plasma drug levels after oral administration and the drug concentration after an IV administration (first pass effect is avoided and therefore no amount drug is lost). A drug must be lipophilic (lipid soluble) in order to pass through biological membranes because biological membranes are made up of a lipid bilayer (phospholipids etc.).
=== Translation === fMet is required for efficient initiation of protein synthesis in most groups of bacteria. The 30S ribosome–mRNA complex specifically recruits tRNAs with a formylated amino acid – tRNAfMet attached to fMet in the natural case. Because the fMet directs initiation, proteins in bacteria start (N-terminus) with a fMet residue instead of a methionine. Further occurrences of the "AUG" codon will result in a normal methionine, because a normal "elongating" tRNAMet is used. The addition of the formyl group to methionine is catalyzed by the enzyme methionyl-tRNA formyltransferase. This modification is done after methionine has been loaded onto tRNAfMet by aminoacyl-tRNA synthetase. Methionine itself can be loaded either onto tRNAfMet or tRNAMet. However, formyltransferase will catalyze the addition of the formyl group to methionine only if methionine has been loaded onto tRNAfMet, not onto tRNAMet. This is because the formyltransferase recognizes specific features of tRNAfMet. The mitochondria of eukaryotic cells, including those of humans, and the chloroplasts of plant cells also initiate protein synthesis with fMet. Given that mitochondria and chloroplasts have this initial protein synthesis with fMet in common with bacteria, this has been cited as evidence for the endosymbiotic theory. Unexpectedly, formyltransferase can also act upon eukaryotic initiator tRNA in living yeast cells. Even under normal conditions, the nuclear-encoded formyltransferase is not completely imported into mitochondria; even more is left in the cytosol under stress.
Sources: en.wikipedia.org
=== Storyline === Minerva takes place in the Half-Life universe. Part of the first level is played in and around a World War II bunker, placed in an unknown, oceanic location, identified in the mod's blog as the Baltic Sea. The player assumes the role of an unnamed protagonist, hinted to be a renegade member of the Combine Overwatch, infiltrating, exploring, and ultimately destroying the Combine base on the island. In contrast to Half-Life 2, no non-hostile characters or dialogue appear; instead, the player is aided by a mysterious guide, the eponymous "Minerva", who serves to relay story information to the player. Minerva, who is never seen, calls herself a goddess, and messages indicate that she is somewhere in Earth's orbit aboard a satellite. The plot is progressed through radio messages from Minerva, relayed as text rather than spoken words. Minerva's communications initially are sarcastic and dismissive, and her demeanour brusque, treating the player as a data-gathering tool at her disposal. Information and storyline is revealed in short segments over the course of the chapters, often with no explanation; for example, in Metastasis she reveals that her (and therefore the player's) goal is to discover the Combine's purposes on and underneath the episode's island, but not why she considers this important or how the player became involved in the first place. As the story progresses the protagonist fights through the base's lower levels, discovering a massive portal by which the Combine are teleporting soldiers.
Comfrey, which contains alkaloids which may be harmful to the liver from chronic use, and particularly is not recommended during pregnancy or when prescription drugs are used; comfrey is not recommended for oral use. Lobelia, which contains alkaloids and has traditional medicine uses for smoking cessation, may cause nausea, vomiting, or dizziness at high doses. Herbal teas can also have different effects from person to person, and this is further compounded by the problem of potential misidentification. The deadly foxglove, for example, can be mistaken for the much more benign (but still relatively toxic to the liver) comfrey. Care must be taken not to use any poisonous plants. The US does not require herbal teas to have any evidence concerning their efficacy, but does treat them technically as food products and require that they be safe for consumption. Fruit or fruit-flavored tea is usually acidic and thus may contribute to erosion of tooth enamel.
== Significance == AKH has become an important area of study, particularly in insect crop pests and insects that act as intermediate or vector hosts for parasites that can affect humans or animals . In experiments where locusts were injected with AKH and lipopolysaccharide (LPS–an immune elicitor found in the cell walls of bacteria) a stronger immune response was observed than in locusts that only received an LPS injection. The spread of malaria by the female mosquito, Anopheles gambiae, is partly dependent on the adipokinetic hormone, Anoga-HrTH (pGlu-Leu-Thr-Phe-Thr-Pro-Ala-Trp-NH2). No crystal structure of this important neuropeptide is available. The NMR restrained molecular dynamic was used to investigate its conformational space in aqueous solution and when bound to a membrane surface. The results showed that Anoga-HrTH has an almost cyclic conformation that is stabilized by a hydrogen bond between the C-terminus and Thr3. When the agonist docks to its receptor, this H-bond is broken and the molecule adopts a more extended structure. Preliminary AKHR docking calculations give the free energy of binding to be −47.30 kJ/mol. Information about the 3D structure and binding mode of Anoga-HrTH to its receptor are vital for the design of suitable mimetics which can act as insecticides.
Sources: en.wikipedia.org
Ezetimibe, sold under the brand name Zetia among others, is a medication used to treat high blood cholesterol and certain other lipid abnormalities. Generally it is used together with dietary changes and a statin. Alone, it is less preferred than a statin. It is taken by mouth. It is also available in the fixed-dose combinations ezetimibe/simvastatin, ezetimibe/atorvastatin, ezetimibe/rosuvastatin, and ezetimibe/bempedoic acid. The most commonly reported adverse events include upper respiratory tract infections, joint pain, diarrhea, and tiredness. Serious side effects may include anaphylaxis, liver problems, depression, and muscle breakdown. Use in pregnancy and breastfeeding is of unclear safety. Ezetimibe works by decreasing cholesterol absorption in the intestines. Ezetimibe was approved for medical use in the United States in 2002. It is available as a generic medication. In 2023, it was the 70th most commonly prescribed medication in the United States, with more than 9 million prescriptions.
She added that the clitoris "extends away from the body in a sleek and slender arc, measuring, on average, over 17 cm from root to tip. Just like a penis, [it] is fully erectile, raising its head in hyena greeting ceremonies, social displays, games of rough and tumble or when sniffing out peers".
== Detection and optical properties == A spectral database exists for tracking polycyclic aromatic hydrocarbons (PAHs) in the universe. Detection of PAHs in materials is often done using gas chromatography-mass spectrometry or liquid chromatography with ultraviolet-visible or fluorescence spectroscopic methods or by using rapid test PAH indicator strips. Structures of PAHs have been analyzed using infrared spectroscopy. PAHs possess very characteristic UV absorbance spectra. These often possess many absorbance bands and are unique for each ring structure. Thus, for a set of isomers, each isomer has a different UV absorbance spectrum than the others. This is particularly useful in the identification of PAHs. Most PAHs are also fluorescent, emitting characteristic wavelengths of light when they are excited (when the molecules absorb light). The extended pi-electron electronic structures of PAHs lead to these spectra, as well as to certain large PAHs also exhibiting semi-conducting and other behaviors.
Sources: en.wikipedia.org
SR9009 is a synthetic REV-ERB agonist used in laboratory research. It is not an approved drug, and its effects in humans are not well characterized. It is often sold as a research chemical under the name Stenabolic.
No. SR9009 targets the nuclear receptors REV-ERBα and REV-ERBβ, not the androgen receptor. This mechanism differs from selective androgen receptor modulators and from exercise mimetics that act on PPARδ.
Published evidence is mainly preclinical, using cell cultures and animal models. Controlled human trials are not well documented in the public literature. Claims about human performance or health effects therefore remain unsupported by robust clinical data.
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.