If you have been reading about NR1D2 and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-06-11. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic REV-ERB agonist | Small molecule; not a steroid or peptide. |
| Primary targets | NR1D1 and NR1D2 | Also known as REV-ERBα and REV-ERBβ. |
| Studied routes | Intraperitoneal in rodents | Oral bioavailability in humans is not established. |
| Human approval | No approved therapeutic indication | No recognized clinical use. |
| Key uncertainty | Human physiological effects | Preclinical findings may not translate. |
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.
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.
==== Direction of liquid pressure ==== An experimentally determined fact about liquid pressure is that it is exerted equally in all directions. If someone is submerged in water, no matter which way that person tilts their head, the person will feel the same amount of water pressure on their ears. Because a liquid can flow, this pressure is not only downward. Pressure is seen acting sideways when water spurts sideways from a leak in the side of an upright can. Pressure also acts upward, as demonstrated when someone tries to push a beach ball beneath the surface of the water. The bottom of a ball is pushed upward by water pressure (buoyancy). When a liquid presses against a surface, there is a net force that is perpendicular to the surface. Although pressure does not have a specific direction, force does. A submerged triangular block has water forced against each point from many directions, but components of the force that are not perpendicular to the surface cancel each other out, leaving only a net perpendicular point. This is why liquid particles' velocity only alters in a normal component after they are collided to the container's wall. Likewise, if the collision site is a hole, water spurting from the hole in a bucket initially exits the bucket in a direction at right angles to the surface of the bucket in which the hole is located. Then it curves downward due to gravity.
Stone-boiling and pit-baking were common techniques which involved heating large pebbles then transferring the hot stones into a perishable container to heat the water. This technology is typified in the Middle Palaeolithic example of the Abri Pataud hearths.
==== DP_PWR (pin 20) ==== Pin 20 on the DisplayPort connector, called DP_PWR, provides 3.3 V (±10%) DC power at up to 500 mA (minimum power delivery of 1.5 W). This power is available from all DisplayPort receptacles, on both source and display devices. DP_PWR is intended to provide power for adapters, amplified cables, and similar devices, so that a separate power cable is not necessary. Standard DisplayPort cable connections do not use the DP_PWR pin. Connecting the DP_PWR pins of two devices directly together through a cable can create a short circuit which can potentially damage devices, since the DP_PWR pins on two devices are unlikely to have exactly the same voltage (especially with a ±10% tolerance). For this reason, the DisplayPort 1.1 and later standards specify that passive DisplayPort-to-DisplayPort cables must leave pin 20 unconnected. However, in 2013 VESA announced that after investigating reports of malfunctioning DisplayPort devices, it had discovered that a large number of non-certified vendors were manufacturing their DisplayPort cables with the DP_PWR pin connected:
Sources: en.wikipedia.org
Although it was legally available online at the time, only 10% of users reported purchasing it online, with most buying from street dealers. Of those who had used mephedrone, 97% said it was easy or very easy to obtain. Around 50% of users reported at least one negative effect associated with the use of mephedrone, of which teeth grinding is the most common. Detailed interviews with users in Northern Ireland similarly found that few purchased mephedrone online, with most interviewees citing concerns that their address would be traced or that family members could intercept the package. On 30 March 2010, Alan Johnson, the then Home Secretary, announced mephedrone would be made illegal "within weeks" after the ACMD sent him a report on the use of cathinones. The legislation would make all cathinones illegal, which Johnson said would "stop unscrupulous manufacturers and others peddling different but similarly harmful drugs". The ACMD had run into problems with the UK Government in 2009 regarding drugs policy, after the government did not follow the advice of the ACMD to reclassify ecstasy and cannabis, culminating in the dismissal of the ACMD chairman, David Nutt, after he reiterated the ACMD's findings in an academic lecture. Several members resigned after he was sacked, and prior to the announcement that mephedrone was to be banned, the trend continued when Dr Polly Taylor resigned, saying she "did not have trust" in the way the government would use the advice given by the ACMD.
Early experiments resembling activity-based profiling were conducted in the 1970s, when small molecules were used to study the mechanism of action of the serine-modifying antibiotic penicillin. The modern era of ABPP began in the 1990s with the development of ABPs compatible with proteomic workflows, and the first applications of ABPP were reported during this decade in studies of proteases. In 1999, the Cravatt lab formally introduced the term "activity-based protein profiling," establishing a framework for systematic functional proteomics. Subsequent work by Ben Cravatt at The Scripps Research Institute, Matthew Bogyo at Stanford University, and Herman S. Overkleeft at Leiden University helped define the field through the design of probes targeting serine hydrolases, cysteine proteases, oxidoreductases, human cytochrome P450s and other enzyme families. Since its inception, ABPP has expanded rapidly, with bibliometric analyses documenting exponential growth in publications and widespread adoption across North America, Europe, and Asia. Advances in mass spectrometry and protein separation technologies further accelerated the integration of ABPP into proteomic research, enabling the characterization of enzyme activity on a global scale and establishing ABPP as a cornerstone of functional proteomics.
3-Arylpropiolonitriles (APN) belong to a class of electron-deficient alkyne derivatives substituted by two electron-withdrawing groups – a nitrile and an aryl moieties. Such activation results in improved selectivity towards highly reactive thiol-containing molecules, namely cysteine residues in proteins. APN-based modification of proteins was reported to surpass several important drawbacks of existing strategies in bioconjugation, notably the presence of side reactions with other nucleophilic amino acid residues and the relative instability of the resulting bioconjugates in the blood stream. The latter drawback is especially important for the preparation of targeted therapies, such as antibody-drug conjugates. The synthesis of 3-arylpropiolonitriles has been the subject of several studies. The most elaborated and often used approach is based on MnO2-mediated free radical oxidation of the corresponding propargylic alcohols obtained using Sonogashira coupling of the corresponding iodo-derivative in the presence of ammonia (Figure 1).
Sources: en.wikipedia.org
=== November === 1 November Amid an ongoing boom in artificial intelligence, the UK hosts the world's first international summit devoted to safely managing the technology. Computer simulations reveal that remnants of a protoplanet named Theia could be inside the Earth, left over from a giant collision in ancient times, which afterwards formed the Moon. Dinkinesh, previously thought to be a single asteroid, is revealed by NASA's Lucy probe to in fact be a binary pair. 5 November – A new record high efficiency of 33.9% is reported for a silicon-perovskite tandem solar cell. This also surpasses the Shockley-Quieser theoretical limit of 33.7% of single junction solar cells for the first time. 6 November – Scientists release the first connectome of neuropeptide signaling in an animal nervous system (C. elegans). On 1 November, a functional atlas of signal propagation in 23,433 pairs of neurons across the worm's head by direct optogenetic activation is published. On 17 November, the development of fluorescent neuropeptide sensors is reported. 7 November – A study finds that "catastrophic ecosystem collapse" of UK forests is likely within the next 50 years, due to a wide range of factors. 8 November – In 10 studies, researchers of the Sc2.0 project report yeast with a half-synthetic genome. 9 November – Surgeons report the first human eye transplant; the patient did not regain sight in the transplanted eye. 10 November – A new scalable technique for carbon nanotube-based MOSFETs is demonstrated.
Osteoclasts are located on the surface of bones and form resorption pits by excreting H+ to the bone surface removing hydroxyapatite, multiple bone minerals, and organic components: collagen and dentin. The purpose of bone resorption is to release calcium to the blood stream for various life processes. These resorption pits are visible under electron microscopy and distinctive trails are formed from prolonged resorption. Osteoclasts have shown to be "absolutely dependent on extracellular acidification". A drop in pH of <0.1 units can cause a 100% increase in osteoclast cell activity, this effect persists with prolonged acidosis with no desensitization, "amplifying the effects of modest pH differences". Osteoclast cells show little or no activity at pH 7.4 and are most active at pH 6.8 but can be further stimulated by other factors such as parathyroid hormone.
The International Ink Library and its Digital Ink Library are an FBI forensic database of inks. It is used to identify writing instruments, makes, models, ink types, and document authenticity. It contains over 15,000 samples of pen, marker, and printer inks dating from the 1920s. As part of the FBI Questioned Documents Branch, it is used to investigate criminal and terrorist cases, fraudulent documents, forgeries, checks, money orders, and threats to persons. It uses high-performance thin-layer chromatography, electrophoresis, ultraviolet spectra, electrospray ionization and mass spectrometry. It also analyzes chemical date tags expressly inserted by ink manufacturers. The database originated in the 1960s from the collection of Antonio Cantu, former Chief Forensic Chemist at the Secret Service, which dedicated the lab in his honor. There is no cost to access, but is limited to U.S. Secret Service directorates, students through coordinated research initiatives, and law enforcement entities. It handles over 500 cases per year. It has been used in such cases as the Jasper Johns forged documents, the Martha Stewart conviction, as well as the 9/11 attacks.
Sources: en.wikipedia.org
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.
REV-ERB receptors generally repress transcription when bound by natural heme. SR9009 is described as an agonist that enhances this repressive activity. The result is altered expression of clock and metabolic genes.
Published controlled human trials are lacking. Some sources cite limited or unofficial reports, but these do not establish safety or efficacy. Claims about human performance effects remain unverified.
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.