circadian clock raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-07-07 and is reviewed periodically as new material appears.
SR9009 is a synthetic small molecule that acts on the nuclear receptors REV-ERBα and REV-ERBβ. These receptors are part of the circadian clock machinery and normally repress transcription of certain target genes. In laboratory research, SR9009 is used as a chemical tool to study how REV-ERB activity influences metabolism, inflammation, and daily biological rhythms. The compound is not an approved medicine, and its effects in humans remain largely uncharacterized. It is often described as an investigational agent rather than a therapeutic product.
REV-ERB proteins typically suppress gene expression by recruiting corepressor complexes to DNA response elements. SR9009 binds these receptors and strengthens that repressive action in cell-based assays. Studies in rodents have reported changes in lipid handling, mitochondrial function, and exercise capacity after treatment. Such findings are often cited as evidence for metabolic effects, but species differences and limited pharmacokinetic data make direct translation to humans uncertain. Researchers continue to examine which effects are robust and which depend on specific experimental conditions.
SR9009 is frequently discussed alongside other REV-ERB ligands, including synthetic agonists and natural heme-related molecules. Its selectivity for REV-ERB over related nuclear receptors has been measured in binding and reporter assays, though off-target activity at higher concentrations is possible. The compound is prohibited in sport by the World Anti-Doping Agency, and it is not approved for any medical use in major jurisdictions. Products sold online may be labeled as research chemicals, and their identity and purity are not guaranteed by regulatory review.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Common name | SR9009 | Also marketed informally as Stenabolic |
| Chemical class | Synthetic REV-ERB agonist | Binds REV-ERBα and REV-ERBβ |
| Molecular formula | C24H30ClN3O4S | Approximate molecular weight 492 g/mol |
| CAS Registry Number | 1379686-30-2 | Identifier for the parent compound |
| Regulatory status | Not approved for human use | Prohibited in sport by WADA |
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.
Preclinical reports describe effects on exercise endurance, mitochondrial content, and lipid profiles in rodents, but these findings come from specific experimental conditions. Many studies use high doses or delivery methods that may not translate directly to human use. SR9009 has been reported to have low oral bioavailability and a short half-life, which complicates interpretation of oral dosing studies. It is not established as safe or effective for any indication. Literature discussions often separate its pharmacological mechanism from unverified claims made in fitness and supplement markets.
==== Drugs ==== A number of medications have been identified which may cause hypoglycemia, through a variety of ways. Moderate quality evidence implicates the non-steroidal anti-inflammatory drug indomethacin and the anti-malarial quinine. Low quality evidence implicates lithium, used for bipolar disorder. Finally, very low quality evidence implicates a number of hypertension medications including angiotensin converting enzyme inhibitors (also called ACE-inhibitors), angiotensin receptor blockers (also called ARBs), and β-adrenergic blockers (also called beta blockers). Other medications with very low quality evidence include the antibiotics levofloxacin and trimethoprim-sulfamethoxazole, progesterone blocker mifepristone, anti-arrhythmic disopyramide, anti-coagulant heparin, and chemotherapeutic mercaptopurine. If a person without diabetes accidentally takes medications that are traditionally used to treat diabetes, this may also cause hypoglycemia. These medications include insulin, glinides, and sulfonylureas. This may occur through medical errors in a healthcare setting or through pharmacy errors, also called iatrogenic hypoglycemia.
=== Etymology === The etymology of melatonin stems from its skin-lightening properties. As detailed in their publication in the Journal of the American Chemical Society, Lerner and his colleagues proposed the name melatonin, derived from the Greek words melas, meaning 'black' or 'dark', and tonos, meaning 'labour', 'colour' or 'suppress'. This naming convention follows that of serotonin, another agent affecting skin color, discovered in 1948 as a modulator of vascular tone, which influenced its name based on its serum vasoconstrictor effect. Melatonin was thus aptly named to reflect its role in preventing the darkening of the skin, highlighting the intersection of biochemistry and linguistics in scientific discovery.
Broad proteomic and transcriptomic profiling has led to innumerable advances in the biomedical space, but the characterization of RNA and protein expression is limited in its ability to inform on the functional characteristics of proteins. Given that transcript and protein expression information leave gaps in knowledge surrounding the effects of post-translational modifications and protein-protein interactions on enzyme activity, and that enzyme activity varies across cell types, disease states, and physiological conditions, specialized tools are required to profile enzyme activity across contexts. Additionally, many identified enzymes have not been sufficiently characterized to yield actionable mechanisms on which to base functional assays. Without a basis for a functional biochemical readout, chemical tools are required to detect drug-protein interactions.
=== 2019 revision of the SI === The definition of the dalton was not affected by the 2019 revision of the SI, that is, 1 Da in the SI is still 1/12 of the mass of a carbon-12 atom, a quantity that must be determined experimentally in terms of SI units. However, the definition of a mole was changed to be the amount of substance consisting of exactly 6.02214076×1023 entities, and the definition of the kilogram was changed as well. As a consequence, the molar mass constant (Mu) remains close to but no longer exactly 1 g/mol, meaning that the mass in grams of one mole of any substance remains nearly but no longer exactly numerically equal to the average mass of an entity in daltons, although the relative standard uncertainty of 4.5×10−10 at the time of the redefinition is insignificant for all practical purposes. Letting ent denote one entity, the smallest amount of any substance (retaining its chemical properties), one mole is an aggregate of an Avogadro number of entities, i.e. 1 mol = N0 ent ≈ (g/Da) ent. This means that the appropriate atomic-scale unit for molar mass is dalton per entity (Da/ent), equal to the constant Mu, very nearly equal to 1 g/mol. For Da/ent to be exactly equal to g/mol, the dalton would need to be redefined exactly in terms of the (fixed-h) kilogram and the Avogadro number so that 1 Da = (1/N0) g, satisfying the relationships N0 = g/Da and 1 mol = N0 ent = (g/Da) ent, thus conforming to the original mole concept—that the Avogadro number is the gram-to-dalton mass unit ratio.
Sources: en.wikipedia.org
== External links == NASA Spinoff homepage NASA Spinoff back issues archive NASA spinoff database Home and City – relating everyday life to NASA research NASA Benefits to You NASA Office of the Chief Technologist NASA STI Program "The Economic Impacts of the U.S. Space Program" by Jerome Schnee, Rutgers University "A Sustainable Method for Quantifying the Benefits of NASA Technology Transfer"
== Consumption and toxicity == As with other plants of the lily family, tulips are poisonous to domestic animals including horses, cats, and dogs. In cats, ingestion of small amounts of tulips can cause vomiting, depression, diarrhoea, hypersalivation, and irritation of the mouth and throat, and larger amounts can cause abdominal pain, tremors, tachycardia, convulsions, tachypnea, difficulty breathing, cardiac arrhythmia, and coma. All parts of the tulip plant are poisonous to cats, while the bulb is especially dangerous. A veterinarian should be contacted immediately if a cat has ingested tulip. In the American East, white-tailed deer eat tulips with no apparent ill effects. Humans generally do not eat tulip bulbs, as they are slow to cultivate and safe preparation practices are not widely known. Although they resemble onions and are occasionally cooked as such, this has led to illness. In the Netherlands they were used as an ersatz ingredient and poverty food during the famine of 1944–45, and some chefs continue to offer them as a delicacy. Removal of the germ (the young stem) is an important preparation step. People who handle tulip bulbs extensively can develop contact dermatitis, known as "tulip fingers", caused by the defensive chemical tulipalin A. The petals are edible to humans, as are the leaves, although some people are allergic.
==== Sex differences ==== In humans, oxytocin differentially affects males and females. Females who are administered oxytocin are overall faster in responding to socially relevant stimuli than males who receive oxytocin. Additionally, after the administration of oxytocin, females show increased amygdala activity in response to threatening scenes; however, males do not show increased amygdala activation. This phenomenon can be explained by examining the role of gonadal hormones, specifically estrogen, which modulate the enhanced threat processing seen in females. Estrogen has been shown to stimulate oxytocin release from the hypothalamus and promote receptor binding in the amygdala. It has also been shown that testosterone directly suppresses oxytocin in mice. This has been hypothesized to have evolutionary significance. With oxytocin suppressed, activities such as hunting and attacking invaders would be less mentally difficult as oxytocin is strongly associated with empathy.
Sources: en.wikipedia.org
SR9009 is a synthetic research compound that binds and modulates the nuclear receptors REV-ERBα and REV-ERBβ. It is used in laboratory studies of circadian biology and metabolism, not as an approved medicine. It is also known by the informal name Stenabolic.
No. SR9009 has not been approved as a therapeutic drug in the United States, European Union, or other major markets. Human safety and efficacy data are very limited. Its presence in consumer products does not imply regulatory approval.
The World Anti-Doping Agency lists SR9009 as a prohibited substance because it can alter gene expression and metabolic pathways relevant to performance. The ban applies at all times, not only during competition. Detection relies on laboratory methods such as mass spectrometry.
It is usually detected by LC-MS or HPLC-UV against a reference standard. In biological matrices, metabolite targeting can improve detection. No universal immunoassay is widely available.