NR1D2 is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-04-25. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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 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.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Not approved for human use | Investigational status in most countries |
| Sports status | Prohibited by WADA | Classified as non-approved or metabolic modulator |
| Common analytical method | LC-MS/MS | Used for trace detection in biological samples |
| Typical test matrices | Urine and blood | Sample choice depends on testing program |
| Human trial data | None published | Effects and safety are not established |
Handling practices for SR9009 focus on minimizing degradation and contamination. The solid is generally stored desiccated at or below -20 °C, protected from light and moisture. Stock solutions are often prepared in dimethyl sulfoxide or ethanol, then aliquoted to avoid repeated freeze–thaw cycles. Aqueous solubility is low, so formulations for animal studies may require cosolvents or suspending agents. Personnel should follow institutional chemical safety procedures, because toxicological data for humans are incomplete.
Regulatory status varies by country and intended use. Major drug agencies have not granted marketing authorization for SR9009 as a medicine, and it is not listed as a controlled substance in many jurisdictions. It is often sold as a research chemical, a category that may fall outside pharmaceutical manufacturing rules. Buyers should verify local laws and supplier documentation, including certificates of analysis. The lack of standardized quality controls raises concerns about identity, purity, and actual content in products marketed online.
In laboratory settings, SR9009 is commonly identified by its molecular structure and its interaction with REV-ERB receptors. Vendors may list it under synonyms such as Stenabolic or REV-ERB agonist, but those names do not define purity or identity. Analytical confirmation typically uses high-performance liquid chromatography with ultraviolet detection or liquid chromatography–mass spectrometry. A reference standard is needed to compare retention time and mass spectrum, because the compound can be confused with related research chemicals.
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.
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.
=== Effects on drug metabolism and drug interactions === The enzymes that are defective in GS – UDP glucuronosyltransferase 1 family, polypeptide A1 (UGT1A1) – are also responsible for some of the liver's ability to detoxify certain drugs. For example, Gilbert syndrome is associated with severe diarrhea and neutropenia in patients who are treated with irinotecan, which is metabolized by UGT1A1. While paracetamol (acetaminophen) is not metabolized by UGT1A1, it is metabolized by one of the other enzymes also deficient in some people with GS. A subset of people with GS may have an increased risk of paracetamol toxicity. Another drug that has increased adverse side-effects in individuals with Gilbert syndrome is atazanavir. Atazanavir is a protease inhibitor for the treatment of HIV. Atazanavir can lead to jaundice in individuals with Gilbert syndrome because it further inhibits the UGT enzymes that already exhibit decreased activity in Gilbert syndrome.
== Honors and awards == Meldal was awarded the 2022 Nobel Prize in Chemistry, jointly with Carolyn R. Bertozzi and Karl Barry Sharpless, "for the development of click chemistry and bioorthogonal chemistry".
=== Pharmacokinetics === Little information thus far has been published on the clinical pharmacokinetics of phenibut. The drug is reported to be well-absorbed. It distributes widely throughout the body and across the blood–brain barrier. Approximately 0.1% of an administered dose of phenibut reportedly penetrates into the brain, with this said to occur to a much greater extent in young people and the elderly. Following a single 250 mg dose in healthy volunteers, its elimination half-life was approximately 5.3 hours and the drug was largely (63%) excreted in the urine unchanged. Some limited information has been described on the pharmacokinetics of phenibut in recreational users taking much higher doses (e.g., 1–3 grams) than typical clinical doses. In these individuals, the onset of action of phenibut has been reported to be 2 to 4 hours orally and 20 to 30 minutes rectally, the peak effects are described as occurring 4 to 6 hours following oral ingestion, and the total duration for the oral route has been reported to be 15 to 24 hours (or about 3 to 5 terminal half-lives).
Sources: en.wikipedia.org
The truce between South Africa and Angola survived only about fifteen months. Negotiations for completing the SADF withdrawal were stalled due to intransigence on both sides concerning the linkage policy, with the two governments clashing over timetables for the withdrawal of Cuban troops and Namibian independence, respectively. While the Soviet Union and Cuba did nothing to impede the dialogue, they feared that Luanda might sacrifice PLAN and MK by agreeing to expel them from the country. Castro confided to Soviet officials that he had no intention of authorising a withdrawal of Cuban forces if the Angolan government signed a non-aggression pact with South Africa similar to the Nkomati Accord. As a last resort, the Cuban presence in Angola would be maintained unilaterally for the purpose of aiding PLAN, with or without Luanda's approval. In October 1984, dos Santos blamed South Africa for stalling the implementation of the Lusaka Accords and called for the US to resolve the impasse by exerting pressure on Botha. On 17 November, dos Santos proposed a five-point peace plan on the following terms: a complete SADF withdrawal from Angola, a renewed ceasefire agreement, a formal pledge by the South African government to begin implementing Namibian independence under the terms of United Nations Security Council Resolution 435, a formal pledge by the Angolan government to begin implementing a three year phased withdrawal of all but 5,000 Cuban troops, and recognition of SWAPO and Cuba as an equal party in negotiations.
A band mask is a heavy duty full-face mask with many of the characteristics of a lightweight demand helmet. In structure it is the front section of a lightweight helmet from above the faceplate to below the demand valve and exhaust ports, including the bailout block and communications connections on the sides. This rigid frame is attached to a neoprene hood by a metal clamping band, hence the name. It is provided with a padded sealing surface around the frame edge which is held firmly against the diver's face by a rubber "spider", a multiple strap arrangement with a pad behind the diver's head, and usually five straps which hook onto pins on the band. The straps have several holes so the tension can be adjusted to get a comfortable seal. A band mask is heavier than other full face masks, but lighter than a helmet, and can be donned more quickly than a helmet. They are often used by the standby diver for this reason.
==== Multi-phase model ==== LNAPLs and DNAPLs can exist in multiple different phases simultaneously upon entering the subsurface environment. The composition of NAPLs is typically described using a multi-phase model that depends on a variety of complex and interrelated parameters, including, but not limited to, viscosity, solubility, and volatility; the possible phases of NAPL include gaseous, solid, aqueous, and immiscible hydrocarbon. The liquid phase of NAPLs is characterized by a physical dividing surface that separates it from the liquid phase of water, indicating immiscibility due to NAPLs' organic structure. That said, some chemical compounds within the NAPL are capable of solubilizing into water, meaning that two liquid phases of NAPL (immiscible hydrocarbon and aqueous solute) can exist simultaneously. The gaseous phase of NAPLs is also responsible for the contamination of groundwater and soil; therefore, the distribution of NAPLs between its various phases is important to quantify in order to assess the extent of contamination and to determine appropriate remediation strategies.
==== Sequencing by expansion ==== On February 2025, Roche announced development of a new, proprietary sequencing method relying on small molecules. This method "encode[s] the sequence of a target nucleic acid molecule (DNA or RNA) into a measurable surrogate polymer called an Xpandomer", and combined amplification with later detected by a nanopore platform with a CMOS camera.
Sources: en.wikipedia.org
No. It is an investigational compound without approved therapeutic indications. It is sold for research purposes only in many jurisdictions.
Sports authorities prohibit it because it is not approved for human use and has potential performance-enhancing effects. It appears on anti-doping lists under non-approved or metabolic modulator categories.
Detection usually uses liquid chromatography-tandem mass spectrometry. The method targets the parent compound or its metabolites in urine or blood.
It is a synthetic REV-ERB agonist used mainly in preclinical research. It is not an approved medicine for human use.