This is a working overview of REV-ERB agonist, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-01-31. Anything still debated is marked as such rather than presented as settled.
SR9009 is often grouped with compounds studied for circadian and metabolic regulation rather than with classical anabolic steroids. Its interactions with nuclear receptors differ from those of androgen receptor ligands, and its proposed mechanisms involve transcriptional control rather than direct hormone signaling. Some sources classify it as a metabolic modulator because of observed effects on energy utilization. The distinction matters for regulation and for interpreting research results across different compound classes.
SR9009 is a synthetic small molecule developed as a REV-ERB agonist. It binds to REV-ERBα and REV-ERBβ, nuclear receptors that help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, the compound alters lipid and glucose handling and influences skeletal muscle oxidative capacity. Its exact effects in humans remain largely uncharacterized because controlled clinical trials have not been reported. The molecule is frequently described in preclinical literature as a metabolic modulator.
Research interest in SR9009 grew from studies showing improved running endurance in mice after short treatment periods. Those experiments linked the compound to increased mitochondrial content and fatty acid oxidation in muscle, but the findings come from animal models and specific dosing schedules. Independent replication has been limited, and the pathways connecting REV-ERB activation to exercise performance are still being mapped. Whether similar responses occur in humans is an open question.
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.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. These receptors help regulate circadian rhythms and metabolic gene expression. In laboratory experiments, SR9009 binds these receptors and alters transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. It is not a naturally occurring compound and has no approved therapeutic use. Research interest stems from its ability to modify energy metabolism in cells and animal models.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C20H24ClN3O4S | Reported for the free base |
| Molecular weight | 437.9 g/mol | Calculated from the formula |
| Primary target | REV-ERBα and REV-ERBβ | Nuclear receptors involved in circadian regulation |
| Solubility | Soluble in DMSO and ethanol | Poorly soluble in water |
| Typical storage | -20 °C, desiccated | Protect from light and moisture |
Most published work on SR9009 consists of preclinical studies. It is widely sold as a research chemical, a category that does not imply safety, efficacy, or pharmaceutical-grade quality. Sports anti-doping organizations have listed SR9009 as a prohibited substance, and its presence in an athlete sample can lead to sanctions. Legal status differs by country; in several jurisdictions it is not approved for human consumption and may be treated as an unapproved new drug.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is not a steroid, peptide, or natural hormone. In scientific literature, it appears under the code SR9009 and in non-scientific contexts as Stenabolic. The compound was identified through chemical screening efforts aimed at targeting circadian clock components. Its status remains investigational, and no regulatory agency has approved it as a human medicine.
REV-ERB proteins help regulate daily cycles in gene expression, including genes tied to lipid and glucose metabolism. SR9009 binds these receptors and alters their activity in cell and animal experiments. Consequences observed in rodents include changes in skeletal muscle oxidative capacity, blood lipid levels, and exercise performance. The precise chain from receptor occupancy to whole-body effects is still an active area of study. Human responses cannot be assumed from rodent data.
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.
Laboratory samples of SR9009 are typically supplied as a white to off-white powder. The compound dissolves readily in organic solvents such as dimethyl sulfoxide and ethanol, while its solubility in water is low. Because of this solubility profile, researchers often prepare concentrated stock solutions in an organic solvent before diluting them into aqueous assay buffers. Light exposure, moisture, and repeated freeze-thaw cycles can degrade many small molecules, so handling procedures usually aim to minimize these factors. Purity is commonly checked before use.
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.
Samoyed dogs are most often white, and can have a brown tint to their double-layer coat, which is naturally dirt-repellent. They have been used in expeditions in both Arctic and Antarctic regions, and have a friendly and agreeable disposition.
Collagenases are enzymes that break the peptide bonds in collagen. They assist in destroying extracellular structures in the pathogenesis of bacteria such as Clostridium. They are considered a virulence factor, facilitating the spread of gas gangrene. They normally target the connective tissue in muscle cells and other body organs. Collagen, a key component of the animal extracellular matrix, is made through cleavage of pro-collagen by collagenase once it has been secreted from the cell. This stops large structures from forming inside the cell itself. In addition to being produced by some bacteria, collagenase can be made by the body as part of its normal immune response. This production is induced by cytokines, which stimulate cells such as fibroblasts and osteoblasts, and can cause indirect tissue damage.
=== Osteoarthritis risk === Variations in the COL2A1 gene may increase susceptibility to osteoarthritis in some individuals. These variations alter amino acids in the pro-alpha1(II) chain, potentially affecting collagen fiber integrity in joint cartilage and contributing to degenerative joint disease.
The discoverers proposed the name "Prometheum" (sic; the spelling was subsequently changed), derived from Prometheus, the Titan in Greek mythology who stole fire from Mount Olympus and brought it down to humans, to symbolize "both the daring and the possible misuse of mankind's intellect". A sample of the metal was made only in 1963. The two sources of natural promethium are rare alpha decays of natural europium-151 (producing promethium-147) and spontaneous fission of uranium (various isotopes). Promethium-145 is the most stable promethium isotope, but the only isotope with practical applications is promethium-147, chemical compounds of which are used in luminous paint, atomic batteries and thickness-measurement devices. Because natural promethium is exceedingly scarce, it is typically synthesized by bombarding uranium-235 (enriched uranium) with thermal neutrons to produce promethium-147 as a fission product.
=== Women of color === The war on drugs also plays a negative role in the lives of women of color. The number of black women imprisoned in the United States increased at a rate more than twice that of black men, over 64% from 1986 to 1991. During that same period, the percentage of females incarcerated for drug-related offenses more than doubled. In 1989, black and white women had similar levels of drug use during pregnancy. However, black women were 10 times as likely as white women to be reported to a child welfare agency for prenatal drug use. In 1997, of women in state prisons for drug-related crimes, forty-four percent were Hispanic, thirty-nine percent were black, and twenty-three percent were white, quite different from the racial make up shown in percentages of the United States as a whole. Statistics in England, Wales, and Canada are similar. Women of color who are implicated in drug crimes are "generally poor, uneducated, and unskilled; have impaired mental and physical health; are victims of physical and sexual abuse and mental cruelty; are single mothers with children; lack familial support; often have no prior convictions; and are convicted for a small quantity of drugs". Additionally, these women typically have an economic attachment to, or fear of, male drug traffickers, creating a power paradigm that sometimes forces their involvement in drug-related crimes. Though there are programs to help them, women of color are usually unable to take advantage of social welfare institutions in America due to regulations.
Sources: en.wikipedia.org
Medina expressed concern about the lack of legal certainty, the weakness of the political opposition, and skepticism regarding the negotiations over Annex C of the Itaipu Treaty, stating that any eventual benefits would primarily favor Brazil. Santiago Peña was criticized for his decision not to attend the funeral of Pope Francis. Peña's absence was regarded as a lack of reciprocity toward the affection shown by Francis for Paraguay, a deeply Catholic nation. Instead, Peña opted for an eleven-day trip to the United States to receive a private award. Peña has also attracted criticism for his international trips, which have been perceived as excessive. By mid-May 2025, Peña was estimated to have made more than 40 international trips as head of state, at a cost of ₲4.000 billion (or US$585,000), and to have spent a total of 126 days outside Paraguayan territory. His supporters have defended these measures, arguing that they attract more private investment to Paraguay.
Production will also face an increasingly complex situation; while OPEC countries still have large reserves at low production prices, newly found reservoirs often lead to higher prices; offshore giants such as Tupi, Guara and Tiber demand high investments and ever-increasing technological abilities. Subsalt reservoirs such as Tupi were unknown in the 20th century, mainly because the industry was unable to probe them. Enhanced oil recovery techniques such as those used at the Daqing Oil Field will continue to play a major role in increasing the world's recoverable oil. The expected availability of petroleum resources has always been around 35 years or even less since the start of the modern exploration. The oil constant, an insider pun in the German industry, refers to that effect. A growing number of divestment campaigns from major funds pushed by newer generations who question the sustainability of petroleum may hinder the financing of future oil prospection and production.
CK1δ seems to be involved in the circadian rhythm, the internal cellular clock, which permits a rhythm of about 24 h. The circadian rhythm mainly consists of a negative feedback loop mediated by (PER) and cryptochrome (CRY) proteins, which can dimerize and shuttle into the nucleus. Here, PER/CRY dimers can inhibit their own transcription, by inhibiting the CLOCK/BMAL1-responsive gene transcription. Alteration of normal circadian rhythm has been observed in different diseases, among them neurological and sleeping disorders. In the nucleus, CK1δ can further inhibit CLOCK/BMAL1-driven transcription by reducing their binding activity to DNA. Moreover, CK1δ/ε can phosphorylate PER proteins and influence their further degradation. Destabilization of the circadian rhythm can be observed after inhibition of PER phosphorylation by CK1δ/ε. In fact, alterations in CK1δ activity lead to changes in the length of the circadian rhythm.
== Mode of action == When used as a food additive, ractopamine added to feed can be distributed by the blood to the muscle tissues, where it serves as a full agonist to murine (mouse or rat) TAAR1, a receptor protein (not necessarily in humans). It is also an agonist to beta-adrenergic receptors and a dopamine releasing agent. A cascade of events will then be initiated to increase protein synthesis, which results in increased muscle fiber size. Ractopamine is known to increase the rate of weight gain, improve feed efficiency, and increase carcass leanness in finishing swine. Its use in finishing swine yields about 3 kg (6.6 lb) of additional lean pork per animal, and improves feed efficiency by 10%. In cattle on 28 January 2004 Elanco Animal Health made Optaflexx commercially available in the US. Optaflexx is a "medicated feed additive that is labeled only for use in steers or market heifers (not breeding heifers or bulls) during the last 28–42 days on feed."
=== Groupings and organizations === Lucha Libre AAA Worldwide, a Mexican wrestling promotion Asian Athletics Association, the continental athletics authority in Asia Amateur Athletic Association of England, the Athletic Association in England Arkansas Activities Association, for high school sports Montreal AAA, an amateur athletic association Triple-A (baseball), a North American Minor League Baseball classification level Senior ice hockey § Senior AAA hockey leagues
Sources: en.wikipedia.org
It is a synthetic REV-ERB agonist used mainly in preclinical research. It is not an approved medicine for human use.
It binds to REV-ERBα and REV-ERBβ, nuclear receptors involved in circadian and metabolic gene regulation. This can alter transcription of genes related to lipid and glucose metabolism in experimental models.
No controlled human trials have established that effect. Endurance findings come primarily from rodent studies, and human responses remain unknown.
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.