NR1D2 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 2026-08-01 and is reviewed periodically as new material appears.
Analytical identification and purity assessment often use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Liquid chromatography–tandem mass spectrometry is used to detect and quantify SR9009 in biological matrices, including urine and blood, for anti-doping or pharmacokinetic studies. Nuclear magnetic resonance spectroscopy can confirm molecular structure. Stability depends on form and storage: the solid is generally more stable than solutions, and repeated freeze–thaw cycles may degrade samples. Purity is typically reported as a percentage from a certificate of analysis.
Regulatory treatment of SR9009 varies by country and context. It is not approved as a therapeutic drug by agencies such as the United States Food and Drug Administration or the European Medicines Agency. Sports authorities list it as a prohibited substance; the World Anti-Doping Agency classifies it among hormone and metabolic modulators. Legal status for personal possession or sale differs across jurisdictions, and some countries may restrict it under analog or research chemical laws. Buyers who seek verified material often rely on independent laboratory testing because online product labels may not match contents.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Common supplier description |
| Solubility | Soluble in DMSO and ethanol | Low solubility in water |
| Typical storage | −20 °C, desiccated, dark | For research samples |
| Analytical method | LC-MS/MS | Used for detection and quantification |
| Regulatory status | Prohibited in sport | WADA metabolic modulator class |
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.
Laboratory studies often administer SR9009 by injection because oral absorption appears poor in rodents. Reported pharmacokinetic properties include rapid metabolism and low systemic exposure after oral dosing. Human pharmacokinetic data are sparse, so absorption, distribution, metabolism, and excretion in people are not well defined. Some research explores related REV-ERB compounds with improved drug-like properties. Regulatory approval for any REV-ERB agonist as a human medicine has not been granted to date.
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.
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.
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.
=== Controversy === Use of this class of drugs has a history of criticism in residential care. As the drugs used can make patients calmer and more compliant, critics claim that the drugs can be overused. Outside doctors can feel under pressure from care home staff. In an official review commissioned by UK government ministers it was reported that the needless use of antipsychotic medication in dementia care was widespread and was linked to 1800 deaths per year. In the US, the government has initiated legal action against the pharmaceutical company Johnson & Johnson for allegedly paying kickbacks to Omnicare to promote its antipsychotic risperidone (Risperdal) in nursing homes. There has also been controversy about the role of pharmaceutical companies in marketing and promoting antipsychotics, including allegations of downplaying or covering up adverse effects, expanding the number of conditions or illegally promoting off-label usage; influencing drug trials (or their publication) to try to show that the expensive and profitable newer atypicals were superior to the older cheaper typicals that were out of patent. Following charges of illegal marketing, settlements by two large pharmaceutical companies in the US set records for the largest criminal fines ever imposed on corporations. One case involved Eli Lilly and Company's antipsychotic Zyprexa, and the other involved Bextra. In the Bextra case, the government also charged Pfizer with illegally marketing another antipsychotic, Geodon.
knot in a protein. With this study, Taylor confirmed the existence of deeply knotted proteins. In 2007, Eric Yeates reported the identification of a molecular slipknot, which is when the molecule contains knotted subchains even though their backbone chain as a whole is unknotted and does not contain completely knotted structures that are easily detectable by computational models. Mathematically, slipknots are difficult to analyze because they are not recognized in the examination of the complete structure. A pentafoil knot prepared using dynamic covalent chemistry was synthesized by Ayme et al. in 2012, which at the time was the most complex non-DNA molecular knot prepared to date. Later in 2016, a fully organic pentafoil knot was also reported, including the very first use of a molecular knot to allosterically regulate catalysis. In January 2017, an 819 knot was synthesized by David Leigh's group, making the 819 knot the most complex molecular knot synthesized. An important development in knot theory is allowing for intra-chain contacts within an entangled molecular chain. Circuit topology has emerged as a topology framework that formalises the arrangement of contacts as well as chain crossings in a folded linear chain. As a complementary approach, Colin Adams. et al., developed a singular knot theory that is applicable to folded linear chains with intramolecular interactions.
The male pilot, who was the only person on board, is taken to hospital by air ambulance. In the first statement to be released since his cancer diagnosis, Charles III thanks the public for their messages of support. 11 February – British journalist Clare Rewcastle Brown accuses Malaysia of seeking "political revenge" for her reporting after a court jailed her in absentia for criminal defamation of a Malaysian royal. 12 February Azhar Ali, the Labour Party's Rochdale by-election candidate, is suspended from the party over comments about Israel and Jewish people. He will however remain on the ballot as the Labour candidate, as it is too late to replace him under electoral law. Three apologises after three days of outages that left around 12,000 people without mobile signals and data. Child killer Colin Pitchfork will be reconsidered for parole after successfully challenging a Parole Board decision to refuse him parole on the grounds he poses too much of a risk if released from prison. 13 February A catastrophic loss of seabird numbers is reported by the RSPB and the British Trust for Ornithology, due to the spread of H5N1 bird flu. Police begin an investigation into reports of antisemitism during a performance by comedian Paul Currie at the Soho Theatre in London, which left Jewish audience members feeling "unsafe" and "threatened". Labour leader Keir Starmer insists he took "decisive action" over comments made by Rochdale by-election candidate Azhar Ali. Cosmetics retailer The Body Shop enters administration, putting more than 2,200 jobs at risk.
Sources: en.wikipedia.org
The electoral system in Sweden is proportional. Of the 349 seats in the unicameral Riksdag, 310 are fixed constituency seats allocated to 29 multi-member constituencies in relation to the number of people entitled to vote in each constituency. The remaining 39 adjustment seats are used to correct the deviations from proportional national distribution that may arise when allocating the fixed constituency seats. There is a constraint in the system that means that only a party that has received at least four per cent of the votes in the whole country participates in the distribution of seats. However, a party that has received at least twelve per cent of the votes in a constituency participates in the distribution of the fixed constituency seats in that constituency.
=== Nitrogenase (nitrogen fixation) === The fixation of atmospheric nitrogen is an energy-intensive process, as it involves breaking the very stable triple bond between the nitrogen atoms. The nitrogenases catalyze the process. One such enzyme occurs in Rhizobium bacteria. There are three components to its action: a molybdenum atom at the active site, iron–sulfur clusters that are involved in transporting the electrons needed to reduce the nitrogen, and an abundant energy source in the form of magnesium ATP. This last is provided by a mutualistic symbiosis between the bacteria and a host plant, often a legume. The reaction may be written symbolically as
== Popular culture == In the 2013 biographical film Dallas Buyers Club, protagonist Ron Woodroof (Matthew McConaughey) promotes the use of injected peptide T as a treatment for HIV/AIDS and Alzheimer's disease and sues the FDA over their efforts to limit his ability to use peptide T, as it was an unapproved medicine. Additional information on Woodroof's court challenge to the FDA related to his obtaining access to peptide T can be found in the article by Marsha Cohen in Hastings Constitutional Law Quarterly (vol.18:471) [Cohen, 1991]. Woodroof's challenge was in part responsible for the 1987 revisions to the FDA investigational drug regulations that expanded access to experimental drugs for patients with serious diseases with no alternative therapies.
In Portugal, public prosecution is conducted by the Public Prosecution Service which is headed by the prosecutor general. The main police organisations of Portugal are the Guarda Nacional Republicana (National Republican Guard), the Polícia de Segurança Pública (Public Security Police), a civilian police force that works in urban areas; and the Polícia Judiciária (Judiciary Police), a senior criminal police body, under the authority of the Minister of Justice and endowed with administrative autonomy. Portugal has 49 correctional facilities run by the Directorate-General for Reintegration and Prison Services (DGRSP). The facilities are classified by security level, and by degree of management complexity, and often house inmates with different legal statuses, risk levels, and criminal trajectories within the same facilities. Despite following a reintegration-oriented penal model, Portugal retains high prison occupancy and an average sentence length of 31.3 months and one of the world's highest prison suicide rates representing around 30% of the 60 to 70 deaths occurring annually.
Sources: en.wikipedia.org
=== Cachexia === Certain diseases can cause a complex muscle wasting syndrome known as cachexia. It is commonly seen in cancer, congestive heart failure, chronic obstructive pulmonary disease, chronic kidney disease and AIDS although it is associated with many disease processes, usually with a significant inflammatory component. Cachexia causes ongoing muscle loss that is not entirely reversed with nutritional therapy. The pathophysiology is incompletely understood but inflammatory cytokines are considered to play a central role. In contrast to weight loss from inadequate caloric intake, cachexia causes predominantly muscle loss instead of fat loss and it is not as responsive to nutritional intervention. Cachexia can significantly compromise quality of life and functional status and is associated with poor outcomes.
1993/2957) A10 Trunk Road (Wadesmill, High Cross and Colliers End Bypass and Slip Road) Order 1993 (S.I. 1993/2963) A10 Trunk Road (North of Ware to South of Puckeridge) (Detrunking) Order 1993 (S.I. 1993/2964) Education (School Inspection) (Wales) (No. 2) (Amendment) Regulations 1993 (S.I. 1993/2968) Scottish College of Textiles (Scotland) Order of Council 1993 (S.I. 1993/2969) Civil Aviation (Route Charges for Navigation Services) (Amendment) Regulations 1993 (S.I. 1993/2970) Hereford and Worcester and West Midlands (County Boundaries) Order 1993 (S.I. 1993/2971) National Health Service (Service Committees and Tribunal) Amendment Regulations 1993 (S.I. 1993/2972) Education (School Inspection) (No. 2) (Amendment) Regulations 1993 (S.I. 1993/2973) Port of Bristol Harbour Revision Order 1993 (S.I. 1993/2974) Civil Aviation (Joint Financing) (Fifth Amendment) Regulations 1993 (S.I. 1993/2975) Gipsy Encampments (East Yorkshire Borough of Beverley) Order 1993 (S.I. 1993/2980)
=== Antibiotic function === The β-lactam family of antibiotic molecules consists of four groups: penicillins, cephalosporins, carbapenems (such as imipenem, ertapenem, meropenem and doripenem) and monobactams. These antibiotics share common structure and mechanism of action. They enter the periplasmic space through porins, where they then inhibit transpeptidases (which are also known as penicillin-binding proteins (PBPs)), enzymes that facilitate peptide cross-links during cell wall synthesis. Their binding to the PBP active site is facilitated in part by their common structure, which is similar to that of D-alanyl-D-alanine. D-Alanyl-D-alanine is a residue on the NAM peptide subunit involved in building peptidoglycan. Carbapenem covalently binds to PBPs, which causes transpeptidases to irreversibly lose their catalytic activity. Inhibition of transpeptidases prevents the formation of cross-links between peptidoglycan polymers and causes a build-up of peptidoglycan precursors. Newly formed peptidoglycan is weakened from the absence of cross-linkages. The continued activity of autolysins, that function like lysozymes and cleave glycosidic and peptide bonds of peptidoglycan in periplasm, weakens the cell wall and leads to osmotic bursting of the bacterial cell. One notable property of carbapenems is their resistance to hydrolysis by bacterial plasmid and chromosomally mediated extended-spectrum β-lactamases (ESBL).
Sources: en.wikipedia.org
Legality depends on the country and the intended use. In many places it is sold as a research chemical, but sports and medicine regulations restrict it.
Detection commonly uses liquid chromatography–tandem mass spectrometry. This method can identify the compound in urine or blood at low concentrations.
Typical guidance is −20 °C, dry, and protected from light. Solutions should be aliquoted and limited freeze–thaw cycles should be used.
SR9009 is a synthetic REV-ERB agonist used in laboratory research. It is not an approved drug, and its effects in humans are not well characterized. It is often sold as a research chemical under the name Stenabolic.