nuclear receptor 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.
Updated 2026-02-10. Numbers and descriptions here follow the published literature rather than marketing material.
SR9009 is not approved as a medicine by major regulatory agencies. It is commonly sold as a research chemical, a category that may fall outside customary drug approval and quality rules. In sports, the World Anti-Doping Agency lists SR9009 as a prohibited substance. Athletes who use it can face sanctions if it is detected in a sample. Legal status varies by country, and importation may be restricted. Enforcement practices differ across borders.
Detection of SR9009 in biological samples usually employs liquid chromatography coupled with tandem mass spectrometry. This method can identify the parent compound and sometimes metabolites in urine or blood. Because exposure can be low and clearance may be rapid, sample timing and limits of detection matter. Laboratories validate assays for sensitivity and specificity. Results are interpreted alongside chain-of-custody and quality-control records. Urine is the common matrix for anti-doping analysis, while blood may be used in research settings.
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.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Not approved as a medicine in major jurisdictions | Sold as a research chemical; legal status varies |
| Anti-doping status | Prohibited by the World Anti-Doping Agency | Listed under non-approved substances or related category |
| Typical analytical method | LC-MS/MS | Used for detection and confirmation in biological samples |
| Storage temperature | −20 °C or lower for solid | Desiccated and protected from light |
| Common solution solvents | DMSO; ethanol | Aqueous solubility is limited |
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.
Analytical methods for SR9009 typically rely on liquid chromatography coupled with tandem mass spectrometry. The technique can separate the parent compound from related substances and detect low concentrations in biological matrices. Urine and blood are common samples in anti-doping testing, while in vitro studies may use cell culture media. Rapid metabolism and low expected concentrations make method validation important for reliable identification. Exact metabolite patterns can vary by species and are not fully mapped.
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.
Laboratory identification of SR9009 typically relies on chromatographic separation coupled to mass spectrometry, often with ultraviolet detection as a secondary check. Nuclear magnetic resonance spectroscopy can confirm molecular structure when a reference standard is available. Because many suppliers sell the compound as a research chemical, independent identity testing is important for experimental reproducibility. A single retention time is not sufficient proof of identity, especially when related compounds may be present. Purity assessments usually report a percentage based on area normalization.
SR9009 is generally described as poorly soluble in water and more soluble in organic solvents such as dimethyl sulfoxide and ethanol. Stock solutions are commonly prepared in an organic solvent before dilution into an aqueous buffer or vehicle. Precipitation can occur if the organic fraction is reduced too quickly or if the final concentration exceeds the compound's solubility limit. Sonication or gentle warming may aid dissolution in some protocols, but excessive heat can promote degradation. Container material and pH can also influence observed solubility.
For long-term storage, SR9009 is typically kept as a solid at low temperature, protected from moisture and light. Desiccated conditions limit hydrolysis, while opaque containers reduce photochemical breakdown. Solutions are less stable than solids and are often stored frozen in aliquots to avoid repeated freeze-thaw cycles. Stability data are not standardized across all suppliers, so users should rely on certificate-of-analysis information when available. Degradation may appear as color change, precipitate, or decreased chromatographic purity.
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.
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.
=== Pharmacodynamics === Noribogainalog acts as a potent serotonin 5-HT2A receptor partial agonist (EC50Tooltip half-maximal effective concentration ≈ 90 nM; EmaxTooltip maximal efficacy = 35–45%). It is also a partial agonist of the serotonin 5-HT6 receptor (Emax = 29%), whereas it is not an agonist of the serotonin 5-HT2B and 5-HT7 receptors. The drug additionally has activity as a dopamine transporter (DAT) chaperone. Noribogainalog does not affect locomotor activity, does not produce the head-twitch response, and does not affect various other physiological and behavioral measures. However, it does produce analgesic effects that can be diminished by the serotonin 5-HT2A receptor antagonist ketanserin. In addition, a subsequent study found that the highest assessed dose produced significant hypolocomotion and that the drug also reduced fentanyl self-administration.
In response to the 2008–09 Israel–Gaza conflict Galloway instigated the Viva Palestina aid convoy to the Gaza Strip in January 2009. "There is a kind of intifada among the youth. They are determined to act", he told Cole Moreton writing for The Independent, adding, "We say, 'Don't be lured by the siren voices of separatism and extremism – join with us and express your anger politically, in a way that will be peaceful, non-violent, and not cost you your life, but will not cost other people their lives either". By mid-February, the organisation said it had raised over £1,000,000 for humanitarian aid in four weeks, although the Charity Commission later found the true figure to be £180,000. On 14 February 2009, Galloway and hundreds of volunteers launched the convoy comprising approximately 120 vehicles intended for use in the Strip, including a fire engine donated by the Fire Brigades Union (FBU), 12 ambulances, a boat and trucks full of medicines, tools, clothes, blankets and gifts for children. The 5,000-mile route passed through Belgium, France, Spain, Morocco, Algeria, Tunisia, Libya and Egypt. The convoy arrived in Gaza on 9 March, accompanied by approximately 180 extra trucks of aid donated by Libya's Gaddafi Foundation. On 10 March 2009, Galloway announced at a press conference in Gaza City attended by several senior Hamas officials: "We are giving you now 100 vehicles and all of their contents, and we make no apology for what I am about to say.
Most adult cnidarians appear as either free-swimming medusae or sessile polyps, and many hydrozoans species are known to alternate between the two forms. Both are radially symmetrical, like a wheel and a tube respectively. Since these animals have no heads, their ends are described as "oral" (nearest the mouth) and "aboral" (furthest from the mouth). Most have fringes of tentacles equipped with cnidocytes around their edges, and medusae generally have an inner ring of tentacles around the mouth. Some hydroids may consist of colonies of zooids that serve different purposes, such as defence, reproduction and catching prey. The mesoglea of polyps is usually thin and often soft, but that of medusae is usually thick and springy, so that it returns to its original shape after muscles around the edge have contracted to squeeze water out, enabling medusae to swim by a sort of jet propulsion.
Sources: en.wikipedia.org
== Further reading == Exercise Physiology for Health, Fitness and Performance. Sharon Plowman and Denise Smith. Lippincott Williams & Wilkins; Third edition (2010). ISBN 978-0-7817-7976-0. Ch. 38. Hormonal Regulation of Energy Metabolism. Berne and Levy Physiology, 6th ed (2008) The effects of increasing exercise intensity on muscle fuel utilisation in humans. Van Loon et al. Journal of Physiology (2001) (OTEP) Open Textbook of Exercise Physiology. Edited by Brian R. MacIntosh (2023)
The last of the Boers finally surrendered in late May 1902 and the war ended with the Treaty of Vereeniging signed on 31 May 1902. After a period of obstinacy, the British offered the Boers generous terms of conditional surrender in order to bring the war to a conclusion. The Boers were given £3,000,000 (equivalent to £319,000,000 in 2025) for reconstruction and promised eventual limited self-government, which was granted in 1906 and 1907. The treaty ended the existence of the Transvaal and Orange Free State as independent Boer republics and placed them within the British Empire. The Union of South Africa was established as a dominion of the British Empire in 1910.
Failure to thrive due to feeding difficulties Axial muscle weakness, particularly affecting neck and trunk flexors High pitched voice Myopathic facial features A high arched or cleft palate may be present. Later developing features include a progressive scoliosis and respiratory impairment. Ophthalmoplegic form (5–10% cases) This typically presents with weakness of abduction and upward gaze. Ptosis may occur. There is also weakness of the proximal limb muscles. Progressive form with hand involvement (10% cases) The type presents with progressive hand weakness and hypermobility. Hip girdle weakness may be present and exercise induced myalgia is common. Scoliosis and respiratory problems are mild or absent. Antenatal form with arthrogryposis multiplex congenita (10% cases) This diagnosis may be suspected prenatally with reduced fetal movements and polyhydramnios. This typically presents with contractures at birth due to poor foetal movement. Other features include a long head, low set ears and a short neck. The respiratory muscles can be moderately to severely affected and problems with breathing are common.
== Biosynthesis == The biosynthetic genes for cordycepin were fully characterized in 2017. The same set of genes also produce pentostatin, another adenosine derivative. Pentostatin protects cordycepin from being deaminated in the fungus, allowing the latter to accumulate. The biosynthetic cluster consists of four genes:
Sources: en.wikipedia.org
Its legal status depends on the country and intended use. It is not an approved medicine in major jurisdictions. In sport, it is prohibited by anti-doping rules.
Laboratories typically use LC-MS/MS to detect SR9009 and related compounds in urine or blood. The method is sensitive but depends on sample collection timing. Confirmatory analysis follows quality-control procedures.
Solid material is generally kept cold, dry, and protected from light. Solutions are often stored in sealed containers at low temperature. Stability beyond recommended periods is not well documented.
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.