This is a working overview of NR1D1, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-05-30. Anything still debated is marked as such rather than presented as settled.
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.
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.
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 |
|---|---|---|
| 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 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.
SR9009 is frequently discussed in fitness and research-chemical contexts, yet it has no approved medical indication. Regulatory agencies have not authorized it for human use, and it is not a standard prescription drug. Some sports organizations list it as a prohibited substance because of its potential performance-enhancing properties. Published human data are sparse, so claims about its effects in people often rely on animal models or anecdotal reports. Quality and identity of online materials can vary widely.
SR9009 is a synthetic small molecule studied as a REV-ERB agonist. REV-ERBα and REV-ERBβ are nuclear receptors that help regulate circadian rhythms and metabolic gene expression. The compound was identified in academic screening efforts to find synthetic ligands for these receptors. In cell and animal studies, SR9009 alters transcription of genes involved in lipid and glucose metabolism, and it can shift circadian behavior. It is not an approved therapeutic agent.
In Japan, indigo became especially important during the Edo period. This was due to a growing textiles industry, and because commoners had been banned from wearing silk, leading to the increasing cultivation of cotton, and consequently indigo – one of the few substances that could dye it. In North America, indigo was introduced into colonial South Carolina by Eliza Lucas, where it became the colony's second-most important cash crop (after rice). As a major export crop, indigo supported plantation slavery there. In the May and June 1755 issues of The Gentleman's Magazine, there appeared a detailed account of the cultivation of indigo, accompanied by drawings of necessary equipment and a prospective budget for starting such an operation, authored by South Carolina planter Charles Woodmason. It later appeared as a book. By 1775, indigo production in South Carolina exceeded 1,222,000 pounds. When Benjamin Franklin sailed to France in November 1776 to enlist France's support for the American Revolutionary War, 35 barrels of indigo were on board the Reprisal, the sale of which would help fund the war effort. In colonial North America, three commercially important species are found: the native I. caroliniana, and the introduced I. tinctoria and I. suffruticosa. In the UK the structure of Natural Indigo was still being sought in 1878 when Edward Schunck published on Indigo e.g. Blue from Polygonum tinctorium and By other Plants (16 April 1878) to the Manchester Literary and Philosophical Society
===== Direct oral anticoagulants (DOACs) ===== DOACs are agents that inhibit the formation of thrombin which is the central effector of coagulation derived from factor Xa. They are categorised into direct thrombin inhibitors and direct factor Xa inhibitors. Direct thrombin inhibitors bind to the active sites of free or clot-bound thrombin to inhibit its effects. Dabigatran etexilate is a common example which has a rapid onset of action. Whereas direct factor Xa inhibitors including apixaban and rivaroxaban directly bind to clotting factor Xa to block its activity, thus inhibiting thrombin formation. DOACs are advantageous over warfarin because of a wider therapeutic window, which indicates safer and more effective use with minimal adverse effects. DOACs also have more stable and predictable anticoagulation effects. Therefore, routine coagulation monitoring is not required.
April 13, 1978: Creation of the State Secretariat for Women's Employment, attached to the Ministry of Labor and Participation; assigned to Nicole Pasquier. July 12, 1978: Law with various measures in favor of maternity. July 26, 1978: Decree amending Decree 68-92 of January 29, 1968, on the special status of police officers and peacekeepers of the national police; women may apply. September 11, 1978: Creation of the Ministry Delegate for Women's Status, replacing the delegation for women's status; assigned to Monique Pelletier. January 2, 1979: Law on working hours and night work for women. December 31, 1979: Law on voluntary termination of pregnancy, completing the January 1975 law. July 17, 1980: Law with various provisions to improve the situation of large families. December 23, 1980: Law on the punishment of rape and certain sexual offenses; rape is defined as: "Any act of sexual penetration, of any kind, committed on another person by violence, coercion, threat, or surprise, is rape"; it becomes a crime. September 30, 1981: Decree on the responsibilities of the Minister Delegate to the Prime Minister, Minister for Women's Rights, Mme Yvette Roudy. October 12, 1981: Publication of three decrees: abortion reimbursed at 75%, residency requirement shortened for foreign women, all public healthcare institutions required to have an abortion center; and a national contraception awareness campaign launched by Minister Yvette Roudy. January 20, 1982: March 8 becomes Women's Day in France, on the proposal of Yvette Roudy and accepted by the Council of Ministers.
=== Organ meats/offal === Lamb's liver, known as lamb's fry in New Zealand and Australia, is eaten in many countries. It is the most common form of offal eaten in the UK, traditionally used in the family favourite and pub grub staple of liver with onions, potentially also with bacon and mashed potatoes. It is a major ingredient, along with the lungs and heart (the pluck), in the traditional Scottish dish of haggis. Lamb testicles or lamb fries are a delicacy in many parts of the world. Lamb kidneys are found in many cuisines across Europe and the Middle East, often split into two halves and grilled (on kebabs in the Middle East), or sautéed in a sauce. They are generally the most highly regarded of all kidneys. Lamb sweetbreads are a delicacy in many cuisines.
Sources: en.wikipedia.org
==== February ==== On 1 February, the Syrian government forces launched attacks toward Suwayda from the areas of Tal Hadid, Mansoura and Walgha, with four mortar shells. Clashes were reported between the National Guard and the Syrian government forces in the area of Mansour and the National Guard declared that it shot down a drone belonging to the Syrian government forces. A Syrian security source reported an attempted infiltration by what it called "outlaw gangs" in the area of Mansoura. On 2 February, the Syrian internal security forces arrested Nasser Faisal Al-Saadi, a member of the National Guard, Eagles of the Whirlwind and Hezbollah, in addition to being the "biggest drug dealer in the region". On 6 February, the Syrian government forces advanced towards the towns of Atil and Salim, reaching Sweida. A Syrian security source reported attacks toward al-Mazra'a. The Syrian government forces launched attacks toward al-Majdal with rocket launchers, killing the civilian Rani Basel Naeem. On 7 February, a Syrian internal security force member shot and killed four people in Al-Matouna, a rural area of Suwayda, and was later arrested by Syrian government forces. The civilians were harvesting olives before they were shot and had received a security clearance from the government to enter their land. On 10 February, the National Guard denied having closed the road between Umm al-Zaytoun and Damascus, declaring it as "misleading and false information" and that the crossing is controlled by Internal Security Forces in Suwayda.
== History == Viracor-IBT was created through the merger of two specialty diagnostic testing labs, Viracor Laboratories and IBT Laboratories. Founded by Dr. Konstance Knox and Dr. Donald Carrigan in Milwaukee County in 2000, Viracor was among the first to commercially offer real-time quantitative PCR assays to diagnose patients with Adenovirus, BK virus and JC virus, among others. Founded in 1983, IBT was the first laboratory to offer a test to definitively diagnose autoimmune causes of chronic hives and developed the first commercially available test to measure pneumococcal antibodies. On 1 July 2014, Ampersand Capital Partners completed the sale of Viracor-IBT Laboratories to Eurofins Scientific for $255 million. The company continued to be known as Viracor-IBT.
Fluorescent techniques have been used to assess a number of protein dynamics including protein tracking, conformational changes, protein–protein interactions, protein synthesis and turnover, and enzyme activity, among others. Three general approaches for measuring protein net redistribution and diffusion are single-particle tracking, correlation spectroscopy and photomarking methods. In single-particle tracking, the individual molecule must be both bright and sparse enough to be tracked from one video to the other. Correlation spectroscopy analyzes the intensity fluctuations resulting from migration of fluorescent objects into and out of a small volume at the focus of a laser. In photomarking, a fluorescent protein can be dequenched in a subcellular area with the use of intense local illumination and the fate of the marked molecule can be imaged directly. Michalet and coworkers used quantum dots for single-particle tracking using biotin-quantum dots in HeLa cells. One of the best ways to detect conformational changes in proteins is to label the protein of interest with two fluorophores within close proximity. FRET will respond to internal conformational changes result from reorientation of one fluorophore with respect to the other. One can also use fluorescence to visualize enzyme activity, typically by using a quenched activity-based proteomics (qABP). Covalent binding of a qABP to the active site of the targeted enzyme will provide direct evidence concerning if the enzyme is responsible for the signal upon release of the quencher and regain of fluorescence.
Ultra short acting (30 minutes): thiopentone, methohexitone Short acting (2 hours): hexobarbitone, cyclobarbitone, pentobarbitone, secobarbitone Intermediate acting (3–6 hours): amobarbitone, butabarbitone Long acting (6 hours): phenobarbitone
== Mechanism of action == PAMORAs act by inhibiting the binding of opioids agonist to the μ-opioid receptor (MOR). The objective of PAMORAs treatment is to restore the enteric nervous system function (ENS). The MOR is found in several places in the body and PAMORAs is a competitive antagonist for binding to the receptor. The MORs in the gastrointestinal tract are the main receptors that PAMORAs are intended to block and prevent the binding of opioid agonists. PAMORAs are used in the treatment of opioid-induced bowel dysfunction (OIBD), a potential adverse effect caused by chronic opioid use. PAMORAs act on the three pathophysiological mechanisms of this adverse effect. They act on gut motility, gut secretion and sphincter function. PAMORAs effect on gut motility is that it can increase the resting tone in the circular muscle layer. The antagonist enhances the effect on tonic inhibition of the muscle tone. This will normalize the tone in the circular muscle layer and therefore prevent opioid-induced rhythmic contractions. When these two factors are combined, it results in decreased transit time. Impliedly these effects will decrease the passive absorption of fluids which helps with decreasing OIBD symptoms such as constipation, gut spasm and abdominal cramp. PAMORAs effect on gut secretion will help reverse the decreased cAMP formation that opioid agonists induce. Also, the antagonist will establish a normal secretion of chloride.
Sources: en.wikipedia.org
=== Fructose consumption === Non-alcoholic and alcoholic fatty liver disease share similar histological features, which suggests that they might share common pathogenic pathways. In laboratory research, high fructose levels promote fat accumulation in the liver by stimulating de novo lipogenesis and reducing the beta-oxidation of fat. Unlike the sugar glucose, the enzyme fructokinase rapidly metabolizes fructose. This leads to a decreased level of intracellular adenosine triphosphate (ATP). The decrease in ATP increases oxidative stress and impairments in proper protein synthesis and mitochondrial function in the liver.
Bipolar cell A type of amacrine cell that transmits signals from photoreceptors (rods and cones) to ganglion cells in the eye, playing a key role in visual processing. Bipolar disorder A mood disorder characterized by alternating episodes of depression and mania, associated with dysregulation in neurotransmitter systems and structural brain changes. Blood–brain barrier (BBB) A selective barrier formed by endothelial cells lining brain capillaries that restricts the passage of substances from the bloodstream into the central nervous system, protecting the brain from pathogens and toxins. Bouton Also known as an axon terminal or synaptic bouton, this is the swollen end of an axon where neurotransmitters are released into the synaptic cleft. Brain The central organ of the nervous system, responsible for processing sensory information, regulating bodily functions, and enabling thought, emotion, memory, and consciousness. Brain-derived neurotrophic factor (BDNF) A protein that supports the survival of existing neurons and encourages the growth and differentiation of new neurons and synapses. It is crucial for long-term memory and synaptic plasticity. Brain plasticity Also called neuroplasticity, this refers to the brain’s ability to reorganize and adapt by forming new neural connections throughout life, especially after injury or in response to learning and experience. Brainstem The posterior part of the brain that connects the cerebrum with the spinal cord.
=== EC 1.5.98 With other, known, physiological acceptors === EC 1.5.98.1: ethylenetetrahydromethanopterin dehydrogenase EC 1.5.98.2: 5,10-methylenetetrahydromethanopterin reductase EC 1.5.98.3: coenzyme F420:methanophenazine dehydrogenase
===== Proposed ===== Despite its superiority to current methods of large-surface-area wound care—gauze wrapping, honey vinegar treatments, and systemic antibiotics—and popular dermal patch uses, spider silk has not found its way into clinical practice. Historically the main reason for this is the difficulty of farming, and harvesting the silk. Unlike silkworms, that spin silk for several easy-to-replicate conditions, spiders spin silk for specific purposes such as catching prey, difficult to replicate in laboratory conditions. In addition, spiders generally tend to be cannibalistic, so breeding sufficient numbers becomes difficult. Forced silking yields unsuitable silks. The most popular proposed use case for dermal applications are:
Sugar phosphates (sugars that have added or substituted phosphate groups) are often used in biological systems to store or transfer energy. They also form the backbone for DNA and RNA. Sugar phosphate backbone geometry is altered in the vicinity of the modified nucleotides. Examples include:
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 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.