circadian rhythm 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 2025-11-14. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Stability depends on physical form, temperature, light exposure, and solvent. Solid SR9009 is generally stored cold and dry, with protection from light to limit degradation. Dimethyl sulfoxide stocks are common for laboratory work, but repeated freeze-thaw cycles can reduce compound integrity. Aqueous solutions may be less stable than organic stocks, and the ethyl ester in the structure can be susceptible to hydrolysis under certain conditions. Researchers typically validate storage conditions and recheck purity before quantitative experiments, especially when using archived material.
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.
| 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 |
Storage conditions for research-grade SR9009 generally involve a freezer at approximately minus twenty degrees Celsius, sometimes lower for long-term preservation. Containers should remain tightly closed and protected from light. Desiccants may be used to limit moisture uptake. Solutions are often stored in aliquots to avoid repeated warming and cooling. Stability data for the compound under various conditions are limited, so laboratories typically follow supplier recommendations and verify performance through periodic analytical checks rather than assuming indefinite stability.
Identity and purity testing for SR9009 commonly uses liquid chromatography coupled with tandem mass spectrometry. This method separates the compound from matrix components and detects it by mass-to-charge transitions, providing sensitive and specific confirmation. Nuclear magnetic resonance spectroscopy can support structural identification, while high-performance liquid chromatography with ultraviolet detection may estimate purity. Because online products labeled as SR9009 may contain other substances or no active compound at all, independent verification is important in research settings. Certificates of analysis are useful but not a substitute for in-house testing.
==== Isobaric labeling ==== Isobaric mass tags (tandem mass tags) are tags that have identical mass and chemical properties that allow heavy and light isotopologues to co-elute together. All mass tags consist of a mass reporter that has a unique number of 13C substitutions, a mass normalizer that has a unique mass that balances the mass of the tag to make all the tags equal in mass and a reactive moiety that crosslinks to the peptides. These tags are designed to cleave at a specific linker region upon high-energy CID, yielding different-sized tags that are then quantitated by LC-MS/MS. Protein or peptide samples prepared from cells, tissues or biological fluids are labeled in parallel with the isobaric mass tags and combined for analysis. Protein quantitation is accomplished by comparing the intensities of the reporter ions in the MS/MS spectra. Three types of tandem mass tags are available with different reactivity: (1) reactive NHS ester which provides high-efficiency, amine-specific labeling (TMTduplex, TMTsixplex, TMT10plex and TMT11plex), (2) reactive iodacetyl function group which labels sulfhydryl-(-SH) groups (iodoTMT) and (3) reactive alkoxyamine functional group which provides covalent labeling of carbonyl-containing compounds (aminoxyTMT). A key benefit of isobaric labeling over other quantification techniques (e.g. SILAC, ICAT, Label-free) is the increased multiplex capabilities and thus increased throughput potential.
In accordance with such findings, high-dose CPA shows equivalent effects on the prostate gland in men relative to high-dose diethylstilbestrol or buserelin, which both achieve castrate levels of testosterone. However, a lower dosage of 50 mg/day CPA has been found to produce a reduction in prostate volume in men with benign prostatic hyperplasia that is reportedly comparable to that observed with surgical or medical castration. In accordance, the dosage of CPA that achieves complete inhibition of the secretory function of the healthy prostate gland is around 50 to 100 mg/day, which is less than the dosage of 200 to 300 mg/day CPA that is used to treat prostate cancer. It has been said that in combined androgen blockade regimens with castration and CPA as the AR antagonist for prostate cancer, due to the marked reduction in androgen levels, lower dosages of CPA than those used as a monotherapy would seem to be equally effective. Relative to the 200 to 300 mg/day dosage of CPA used as a monotherapy in prostate cancer, the recommended dosage in combined androgen blockade is 100 to 200 mg/day. It has been stated that this dosage should be more than necessary to inhibit the effects of the remaining adrenal androgens in castrated men. Despite considerable suppression of testosterone levels, only a modest suppression of spermatogenesis typically occurs with 5 to 10 mg/day CPA, and azoospermia occurs only occasionally. Conversely, a combination of testosterone enanthate injections with 12.5 to 100 mg/day CPA results in azoospermia in most men.
== Pharmacology == Setmelanotide binds to and activates MC4 receptors in the paraventricular nucleus (PVN) of the hypothalamus and in the lateral hypothalamic area (LHA), areas involved in the regulation of appetite, and this action is thought to underlie its appetite suppressant effects. In addition to reducing appetite, setmelanotide increases resting energy expenditure in both obese animals and humans. Importantly, unlike certain other MC4 receptor agonists, such as LY-2112688, setmelanotide has not been found to produce increases in heart rate or blood pressure. Setmelanotide has been reported to possess the following activity profile (cAMP, EC50): MC4 (0.27 nM) > MC3 (5.3 nM) ≈ MC1 (5.8 nM) > MC5 (1600 nM) ≟ MC2 (>1000 nM). (19.6-fold selectivity for MC4 over MC3, the second target of highest activity.)
Sources: en.wikipedia.org
== Examples == In the last 40 years, there has been a significant amount of research on metal binding peptides and their characteristics, structures, and chemical reactivities. Vincent L. Pecoraro and his group investigate the interaction of peptides with heavy metals in the body; Katherine Franz leads a group studying Cu-binding peptides; Angela Lombardi and her unit focus on the development of artificial metalloenzymes and similar peptide systems, and the group of Peter Faller focuses on redox reactivity of Cu-peptides.
Fibronectin is important for guiding cell attachment and migration during embryonic development. In mammalian development, the absence of fibronectin leads to defects in mesodermal, neural tube, and vascular development. Similarly, the absence of a normal fibronectin matrix in developing amphibians causes defects in mesodermal patterning and inhibits gastrulation. Fibronectin is also found in normal human saliva, which helps prevent colonization of the oral cavity and pharynx by pathogenic bacteria.
Benzodiazepines are sometimes used for criminal purposes; they serve to incapacitate a victim in cases of drug assisted rape or robbery. Overall, anecdotal evidence suggests that temazepam may be the most psychologically habit-forming benzodiazepine. Non-medical temazepam use reached epidemic proportions in some parts of the world, in particular, in Europe and Australia, and is a major addictive substance in many Southeast Asian countries. This led authorities of various countries to place temazepam under a more restrictive legal status. Some countries, such as Sweden, banned the drug outright. Temazepam also has certain pharmacokinetic properties of absorption, distribution, elimination, and clearance that make it more apt to non-medical use compared to many other benzodiazepines.
== History == Imetelstat is the first telomerase inhibitor to enter clinical trials. Chemically, imetelstat is a synthetic conjugate consisting of three parts: GRN163, a thio phosphoramide oligonucleotide, and a palmitoyl lipid group. GRN163 is the pharmacological component with telomerase inhibition based on experiments with poly-G oligonucleotides first conducted at the University of Nebraska Medical Center under contract with Lynx Therapeutics. The palmitic acid moiety is conjugated via a phosphothioate linkage to the backbone of the antisense oligonucleotide. Telomere shortening and lower cell viability are observed after inhibition of telomerase activity in vitro. IC50 values ranged from 50 to 200nM for 10 different pancreatic cell lines. The efficacy of imetelstat was evaluated in IMerge (NCT02598661), a randomized (2:1), double-blind, placebo-controlled multicenter trial in 178 participants with myelodysplastic syndromes. Participants received an intravenous infusion of imetelstat 7.1 mg/kg or placebo in 28-day treatment cycles until disease progression or unacceptable toxicity. Randomization was stratified by prior red blood cell transfusion burden and by International Prognostic Scoring System (IPSS) risk group. All participants received supportive care, which included red blood cell transfusions.
Sources: en.wikipedia.org
=== Andrey Lyapchev's cabinet === At the end of 1925 Kimon Georgiev actively participated in the events that led to the fall of Aleksander Tsankov. He was one of the activists of the People's Congress who at that time advocated changes in the cabinet, and was charged by the leadership of the Democratic Congress to present its decision in this direction to Tsankov. Discussed as a possible interior minister in a new cabinet, on 4 January 1926 he became Minister of Railways, Posts and Telegraphs in Andrey Lyapchev's first cabinet. After leaving the cabinet, Georgiev was among the members of the internal opposition in the Sgora, grouped around the newspaper "Luch" edited by Petar Todorov, which is why its representatives are often called racists. They advocate stronger state intervention in the economy, limiting partisan appointments in the administration and active action against IMRO. In response, Lyapchev made some concessions, such as the removal of war minister Ivan Valkov. A split occurred within the Radiationist group itself in 1930, when three of its members, including Aleksander Tsankov, were given cabinet seats, and the more extreme opponents, led by Kimon Georgiev, continued to criticize the government. In September, Georgiev himself sharply attacked the war minister in parliament over the Spy Affair. In November, a final rift between the two groups occurred, with the extreme opposition increasingly distancing itself from the Democratic Alliance, consolidating around the Political Circle "Zveno".
The functions of AGPs in plant growth and development processes rely heavily on the incredible diversity of their glycan and protein backbone moieties. In particular, it is the AG polysaccharides that are most likely to be involved in development. Most of the biological roles of AGPs have been identified through T-DNA insertional mutants characterization of genes or enzymes involved in AGP glycosylation, primarily in Arabidopsis thaliana. The galt2-6 single mutants revealed some physiological phenotypes under normal growth conditions, including reduced root hair length and density, reduced seed set, reduced adherent seed coat mucilage, and premature senescence. However, galt2galt5 double mutants showed more severe and pleiotropic physiological phenotypes than the single mutants with respect to root hair length and density and seed coat mucilage. Similarly, hpgt1hpgt2hpgt3 triple mutants showed several pleiotropic phenotypes including longer lateral roots, increased root hair length and density, thicker roots, smaller rosette leaves, shorter petioles, shorter inflorescence stems, reduced fertility, and shorter siliques. In the case of GALT31A, it has been found to be essential for embryo development in Arabidopsis. A T-DNA insertion in the 9th exon of GALT31A resulted in embryo lethality of this mutant line. Meanwhile, knockout mutants for KNS4/UPEX1 have collapsed pollen grains and abnormal pollen exine structure and morphology. In addition, kns4 single mutants exhibited reduced fertility, confirming that KNS4/UPEX1 is critical for pollen viability and development.
The Romanian Armed Forces consist of land, air, and naval forces led by a Commander-in-chief under the supervision of the Ministry of National Defence, and by the president as the Supreme Commander during wartime. The Armed Forces consist of approximately 55,000 reservists and 71,500 active military personnel—35,800 for land, 10,700 for air, 6,600 for naval forces, and 16,500 in other fields. Total defence spending in 2023 accounted for 2.44% of total national GDP, or approximately US$8.48 billion, with a total of $9 billion intended to be spent until 2026 for modernisation and acquisition of new equipment. Conscription stopped in 2007, when Romania switched to a volunteer army. The Air Force operates F-16AM/BM MLU fighters, C-27J Spartan and C-130 Hercules transport aircraft, as well as IAR 330 and IAR 316 helicopters. A procurement programme for F-35 fifth-generation fighters is also currently being carried out. The Naval Forces operate three frigates, of which two are Type 22 frigates acquired from the British Royal Navy, as well as four corvettes. The River Flotilla operates Mihail Kogălniceanu and Smârdan-class river monitors. Romania contributed troops to the international coalition in Afghanistan beginning in 2002, with a peak deployment of 1,600 troops in 2010 (which was the 4th largest contribution according to the US). Its combat mission in the country concluded in 2014. Romanian troops participated in the occupation of Iraq, reaching a peak of 730 soldiers before being slowly drawn down to 350 soldiers.
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.
The most common approach is liquid chromatography-tandem mass spectrometry, often after extraction from blood, urine, or tissue. Ultraviolet detection and nuclear magnetic resonance spectroscopy are used mainly for reference material characterization. Isotope-labeled internal standards improve accuracy.