nuclear receptor raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-12-15. Anything still debated is marked as such rather than presented as settled.
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 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.
Mechanistically, SR9009 binds the ligand-binding domain of REV-ERBα/β and enhances recruitment of corepressor complexes. This represses target genes rather than activating them. Because REV-ERB proteins normally compete with ROR proteins at shared response elements, the net effect depends on tissue and timing. Researchers use SR9009 to probe how nuclear receptor signaling links the clock to metabolism, inflammation, and muscle biology. Findings are largely preclinical, and the precise contribution of each receptor subtype remains under study.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic small molecule | Studied as a REV-ERB agonist |
| Molecular formula | C20H24ClN3O4S | Reported for the neutral compound |
| Appearance | Off-white to pale yellow solid | Typical research-grade material |
| Solubility | Sparingly soluble in water | Soluble in solvents such as DMSO |
| Common synonyms | SR9009; Stenabolic | Stenabolic is an informal alias |
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.
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 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.
With the merger of the laboratories into a single entity, the history offices at each site ceased to maintain independent histories and all history functions were transferred to a central History Office located at AFRL HQ at Wright-Patterson AFB. In homage to the predecessor laboratories, the new organization named four of the research sites after the laboratories and assured that each laboratory's history would be preserved as inactivated units. In 2023, the National Advanced Air Mobility Center of Excellence was completed to help the Laboratory, private companies, and local academics collaborate on the research of eVTOL and UAS aircraft.
Acceptance sampling uses statistical sampling to determine whether to accept or reject a production lot of material. It has been a common quality control technique used in industry. It is usually done as products leave the factory, or in some cases even within the factory. Most often a producer supplies a consumer with several items and a decision to accept or reject the items is made by determining the number of defective items in a sample from the lot. The lot is accepted if the number of defects falls below where the acceptance number or otherwise the lot is rejected. In general, acceptance sampling is employed when one or several of the following hold: testing is destructive; the cost of 100% inspection is very high; and 100% inspection takes too long. A wide variety of acceptance sampling plans is available. For example, multiple sampling plans use more than two samples to reach a conclusion. A shorter examination period and smaller sample sizes are features of this type of plan. Although the samples are taken at random, the sampling procedure is still reliable.
Anti-obesity medication or weight loss medications are pharmacological agents that reduce excess body fat and cause weight loss. These medications alter one of the fundamental processes of weight regulation, by: reducing appetite and consequently energy intake, increasing energy expenditure, redirecting nutrients from adipose to lean tissue, or interfering with the absorption of calories. Weight loss drugs have been developed since the early twentieth century, and many have been banned or withdrawn from the market due to adverse effects, including deaths; other drugs proved ineffective. Although many earlier drugs were stimulants such as amphetamines, in the early 2020s, GLP-1 receptor agonists became popular for weight loss. As of 2023, the medications liraglutide, naltrexone/bupropion, orlistat, semaglutide, tirzepatide and phentermine/topiramate are approved by the US Food and Drug Administration (FDA) for weight management in combination with reduced-calorie diet and increased physical activity. Medications to treat obesity may be considered in those with a body mass index above 30, or above 27 with obesity related complications (such as hypertension, hyperlipidemia, cardiovascular disease, or obstructive sleep apnea). As of 2022, no medication has been shown to be as effective at long-term weight reduction as bariatric surgery.
Sources: en.wikipedia.org
Acanthosis nigricans-muscle cramps-acral enlargement syndrome, also known as Acanthosis nigricans-insulin resistance-muscle cramps-acral enlargement syndrome, is an extremely rare genetic disorder which is characterized by the appearance of acanthosis nigricans, insulin resistance, muscle cramps of severe intensity, and acral hypertrophy/enlargement. Only 2 cases have been reported in medical literature. It was first discovered when Jeffrey Flier and his colleagues described two siblings of the opposite sex with the symptoms mentioned above. (plus: large, chunky hands), the sister had virilized polycystic ovaries. After being treated with dilantin, the cramps' severity lowered and the brother's insulin resistance also lowered. The inheritance pattern of this disorder is thought to be autosomal recessive.
C-reactive protein (CRP), a marker of systemic inflammation, is also increased in obstructive sleep apnea (OSA). CRP and interleukin-6 (IL-6) levels were significantly higher in patients with OSA compared to obese control subjects. Patients with OSA have higher plasma CRP concentrations that increased corresponding to the severity of their apnea-hypopnea index score. Treatment of OSA with CPAP (continuous positive airway pressure) significantly alleviated the effect of OSA on CRP and IL-6 levels.
Amanda Grace Paulovich is an oncologist, and a pioneer in proteomics using multiple reaction monitoring mass spectrometry to study tailored cancer treatment. Paulovich received a BS in Biological Sciences from Carnegie Mellon University in 1988, a PhD in Genetics from University of Washington in 1996, under the direction of Leland Hartwell. She also received a MD from University of Washington in 1998. Follow her residency in Internal Medicine at Massachusetts General Hospital, she also completed a Postdoctoral Fellowship in Computational Biology at the Massachusetts Institute of Technology Whitehead Center for Genomic Research in 2003, and a Fellowship in Medical Oncology at the Dana Farber Cancer Institute in 2004.
Sources: en.wikipedia.org
In both pharmacology and nutrition sciences, bioavailability is measured by calculating the area under curve (AUC) of the drug concentration time profile. Bioavailability is a term used to describe the percentage of an administered dose of a xenobiotic that reaches the systemic circulation unchanged. It is denoted by the letter f (or, if expressed in percent, by F). In nutritional science, which covers the intake of nutrients and non-drug dietary ingredients, the concept of bioavailability lacks the well-defined standards associated with the pharmaceutical industry. The pharmacological definition cannot apply to these substances because utilization and absorption is a function of the nutritional status and physiological state of the subject, resulting in even greater differences from individual to individual (inter-individual variation). Therefore, bioavailability for dietary supplements can be defined as the proportion of the administered substance capable of being absorbed and available for use or storage.
AH receptor-interacting protein (AIP) also known as aryl hydrocarbon receptor-interacting protein, immunophilin homolog ARA9, or HBV X-associated protein 2 (XAP-2) is a protein that in humans is encoded by the AIP gene. The protein is a member of the FKBP family. AIP may play a positive role in aryl hydrocarbon receptor-mediated signalling possibly by influencing its receptivity for ligand and/or its nuclear targeting. AIP is the cellular negative regulator of the hepatitis B virus (HBV) X protein. Further, it's been known to suppress antiviral signaling and the induction of type I interferon by targeting IRF7, a key player in the antiviral signal pathways. AIP consists of an N-terminal FKBP52 like domain and a C-terminal TPR domain. AIP mutations may be the cause of a familial form of acromegaly, familial isolated pituitary adenoma (FIPA). Somatotropinomas (i.e. GH-producing pituitary adenomas), sometimes associated with prolactinomas, are present in most AIP mutated patients.
AM function can be compared to another peptide called pro-adrenomedullin N-terminal 20 peptide (PAMP), which both originate from a common precursor leading to angiogenesis, vasodilation, and anti-inflammatory processes. These two peptides are expressed in the gastrointestinal (GI) tract at a mass level, serving as GI hormones controlling processes like insulin secretion and gastric emptying. Past studies reveal that AM and PAMP also impact gut microbiome composition by fostering the development of beneficial bacteria (i.e., Bifidobacterium and Lactobacillus) and diminishing detrimental microbes.
Ancestim is a recombinant methionyl human stem cell factor, branded by Amgen as StemGen. It was developed by Amgen and sold to Biovitrium, now Swedish Orphan Biovitrum, in December, 2008. It is a 166 amino acid protein produced by E. coli bacteria into which a gene has been inserted for soluble human stem cell factor. It has a monomeric molecular weight of approximately 18,500 daltons and normally exists as a noncovalently associated dimer. The protein has an amino acid sequence that is identical to the natural sequence predicted from human DNA sequence analysis, except for the addition of an N-terminal methionine retained after expression in E. coli. Because Ancestim is produced in E. coli, it is nonglycosylated. Ancestim is supplied as a sterile, white, preservative-free, lyophilised powder for reconstitution and administration as a subcutaneous (SC) injection and is indicated for use in combination with filgrastim for mobilizing peripheral hematopoietic stem cells for later transplantation in certain cancer patients.
Sources: en.wikipedia.org
SR9009 is a synthetic research compound that activates the REV-ERBα and REV-ERBβ nuclear receptors. It is not an approved drug and has no established human therapeutic use. Most published biological data come from cell and rodent studies.
No. SR9009 is frequently mislabeled as a SARM in online discussions, but it does not target androgen receptors. Its known mechanism involves REV-ERB nuclear receptors and circadian-metabolic gene regulation.
Human clinical data are very limited. There is no approved human use, and safety and efficacy in people are not established. Most evidence comes from preclinical models, so effects observed in animals may not apply to humans.
SR9009 is a synthetic compound investigated as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is used in preclinical research on circadian rhythm and metabolism. It is not an approved drug.