circadian rhythm comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-09-28. Numbers and descriptions here follow the published literature rather than marketing material.
Most published work on SR9009 consists of preclinical studies. It is widely sold as a research chemical, a category that does not imply safety, efficacy, or pharmaceutical-grade quality. Sports anti-doping organizations have listed SR9009 as a prohibited substance, and its presence in an athlete sample can lead to sanctions. Legal status differs by country; in several jurisdictions it is not approved for human consumption and may be treated as an unapproved new drug.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is not a steroid, peptide, or natural hormone. In scientific literature, it appears under the code SR9009 and in non-scientific contexts as Stenabolic. The compound was identified through chemical screening efforts aimed at targeting circadian clock components. Its status remains investigational, and no regulatory agency has approved it as a human medicine.
REV-ERB proteins help regulate daily cycles in gene expression, including genes tied to lipid and glucose metabolism. SR9009 binds these receptors and alters their activity in cell and animal experiments. Consequences observed in rodents include changes in skeletal muscle oxidative capacity, blood lipid levels, and exercise performance. The precise chain from receptor occupancy to whole-body effects is still an active area of study. Human responses cannot be assumed from rodent data.
Detection in biological samples can be complicated by rapid metabolism and low circulating concentrations. Some studies report phase I and phase II metabolites, and analytical methods may need to target those species in addition to the parent compound. Immunoassays are not broadly available, so mass spectrometry remains the main confirmatory approach. For anti-doping testing, laboratories look for SR9009 and its metabolites using validated LC-MS methods. Open questions include how long metabolites remain detectable and how different routes of administration alter detection windows.
In laboratory settings, SR9009 is typically characterized by liquid chromatography–mass spectrometry (LC-MS) or high-performance liquid chromatography with ultraviolet detection (HPLC-UV). These methods can confirm identity and estimate purity, but they require reference standards for accurate quantification. Because SR9009 is not a licensed pharmaceutical, no harmonized pharmacopeial monograph exists. Laboratories often validate in-house methods for matrices such as plasma, urine, or cell culture media. Sample preparation may involve protein precipitation or liquid-liquid extraction before analysis.
| Property | Value | Notes |
|---|---|---|
| Common name | SR9009 | Also referred to as Stenabolic in non-scientific contexts. |
| Chemical class | Synthetic small molecule | Not a steroid or peptide hormone. |
| Receptor target | REV-ERBα and REV-ERBβ | Nuclear receptor agonist in preclinical studies. |
| Development status | Investigational | No approved human therapeutic indication. |
| Regulatory attention | Prohibited in sport | Listed by anti-doping authorities. |
SR9009 stability depends on temperature, moisture, light, and solvent. Solid material is generally kept cool and dry, while solutions may require protection from repeated warming and cooling. Degradation can appear as color changes, precipitate, or new chromatographic peaks. Researchers should follow supplier instructions and their own stability data. Long-term storage conditions for human use have not been established because the compound lacks approved clinical formulation.
SR9009 is supplied as a solid research chemical, often in milligram quantities. Laboratories typically weigh it in a controlled environment because fine powders can disperse. Stock solutions are commonly prepared in dimethyl sulfoxide and stored in small aliquots to reduce freeze-thaw cycles. Personal protective equipment and chemical fume hoods are standard when handling unknown or potent compounds. These practices address laboratory safety rather than human use.
Identity and purity of SR9009 samples are usually checked with chromatographic and spectrometric methods. High-performance liquid chromatography can separate the compound from related impurities, while mass spectrometry provides molecular mass confirmation. Nuclear magnetic resonance spectroscopy may be used for structural verification in research settings. No single method proves biological activity, and certificates of analysis should be reviewed alongside raw data. Independent testing is often needed because online products vary widely.
Pharmacokinetic data for SR9009 are limited in published literature. Some reports indicate low oral bioavailability and rapid clearance in animals, which complicates interpretation of exposure and effect. Researchers often use injected routes in preclinical work to achieve measurable systemic levels. Analytical studies rely on mass spectrometry to detect the parent compound and its metabolites. Questions about tissue distribution, active metabolites, and long-term consequences remain open. Species differences in metabolism can affect observed half-life and target engagement.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. These receptors help regulate circadian rhythms and metabolic gene expression. In laboratory experiments, SR9009 binds these receptors and alters transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. It is not a naturally occurring compound and has no approved therapeutic use. Research interest stems from its ability to modify energy metabolism in cells and animal models.
In rodent studies, SR9009 has been reported to increase mitochondrial content in skeletal muscle and improve exercise endurance under some conditions. These findings led to popular descriptions such as an exercise mimetic, although that term oversimplifies the biology. Effects vary by dose, timing, tissue, and model. The compound's influence on circadian pathways means that time of administration can matter in experiments. Whether similar metabolic changes occur in humans remains largely unexplored in controlled published trials.
The historian Sergio Luzzatto recounted that in 1919, Maria De Vito (the cousin of the local pharmacist Valentini Vista at Foggia) testified that the young Pio bought carbolic acid and the great quantity of four grams of veratrine "without presenting any medical prescription whatsoever". Pio maintained that the carbolic acid was used to sterilize syringes used for medical treatments and that after being subjected to a practical joke where veratrine was mixed with snuff tobacco, causing uncontrollable sneezing after ingestion, he decided to acquire his own quantity of the substance in order to play the same joke on his confreres. Amico Bignami in a report wrote that the wounds were caused by "neurotic necrosis". He suggested they had been inflicted unconsciously by suggestion and artificially maintained by iodine that Pio had used as a disinfectant. In 1922, physician Agostino Gemelli went to visit Padre Pio where he observed and interviewed him, but Gemelli was denied the right to physically examine the stigmata without an authorization from the Holy Office. Gemelli, irritated and offended for not being allowed to directly examine the stigmata, wrote while reviewing the previous reports, that Pio was a hysteric and his stigmata were self-induced, not of supernatural origin. Gemelli also speculated that his wounds were kept open with carbolic acid. Giorgio Festa, who examined the stigmata of the friar on October 28, 1919, wrote in his report that they "are not the product of a trauma of external origin, nor are they due to the application of potently irritating chemicals".
The International System of Units (SI) unit of radioactive activity is the becquerel (Bq), named in honor of the scientist Henri Becquerel. One Bq is defined as one transformation (or decay or disintegration) per second. An older unit of radioactivity is the curie, Ci, which was originally defined as "the quantity or mass of radium emanation in equilibrium with one gram of radium (element)". Today, the curie is defined as 3.7×1010 disintegrations per second, so that 1 curie (Ci) = 3.7×1010 Bq. For radiological protection purposes, although the United States Nuclear Regulatory Commission permits the use of the unit curie alongside SI units, the European Union European units of measurement directives required that its use for "public health ... purposes" be phased out by 31 December 1985. Absorbed dose is measured in grays (Gy), while equivalent and effective doses are expressed in sieverts (Sv).
=== History === Commercial production of ethylene oxide dates back to 1914 when BASF built the first factory which used the chlorohydrin process (reaction of ethylene chlorohydrin with calcium hydroxide). The chlorohydrin process was unattractive for several reasons, including low efficiency and loss of valuable chlorine into calcium chloride. More efficient direct oxidation of ethylene by air was invented by Lefort in 1931 and in 1937 Union Carbide opened the first plant using this process. It was further improved in 1958 by Shell Oil Co. by replacing air with oxygen and using elevated temperature of 200–300 °C (390–570 °F) and pressure (1–3 MPa (150–440 psi)). This more efficient route accounted for about half of ethylene oxide production in the 1950s in the US, and after 1975 it completely replaced the previous methods. The production of ethylene oxide accounts for approximately 11% of worldwide ethylene demand.
== Formation and maintenance == The acidic pH at the skin's surface is mainly maintained by free amino acids and α-hydroxy acids (lactic acids) excreted from sweat; free fatty acids and amino acids from sebum; and urocanic acid and pyroglutamic acid.
Several countries mandate that all travellers, or all foreign travellers, be fingerprinted on arrival and will refuse admission to or even arrest travellers who refuse to comply. In some countries, such as the United States, this may apply even to transit passengers who merely wish to change planes rather than go landside. Fingerprinting countries/regions include Afghanistan, Argentina, Brunei, Cambodia, China, Ethiopia, Ghana, Guinea, India, Japan, Kenya (both fingerprints and a photo are taken), Malaysia upon entry and departure, Mongolia, Saudi Arabia, the Schengen Area, Singapore, South Korea, Taiwan, Thailand, Uganda, the United Arab Emirates and the United States. Many countries also require a photo be taken of people entering the country. The United States, which does not fully implement exit control formalities at its land frontiers (although long mandated by its own legislation), intends to implement facial recognition for passengers departing from international airports to identify people who overstay their visa. Together with fingerprint and face recognition, iris scanning is one of three biometric identification technologies internationally standardised since 2006 by the International Civil Aviation Organization (ICAO) for use in e-passports and the United Arab Emirates conducts iris scanning on visitors who need to apply for a visa. The United States Department of Homeland Security has announced plans to greatly increase the biometric data it collects at US borders.
Sources: en.wikipedia.org
=== Lung overpressure injury === A free-diver can dive and safely ascend without exhaling, because the gas in the lungs had been inhaled at atmospheric pressure, is compressed during the descent, and expands back to the original volume during ascent. A scuba or surface-supplied diver breathing gas at depth from underwater breathing apparatus fills their lungs with gas at an ambient pressure greater than atmospheric pressure. At 10 metres the lungs contain twice the amount of gas that they would contain at atmospheric pressure, and if they ascend without exhaling the gas will expand to match the decreasing pressure until the lungs reach their elastic limit, and begin to tear, and is very likely to sustain life-threatening lung damage. Besides tissue rupture, the overpressure may cause ingress of gases into the tissues through the ruptures, and further afield through the circulatory system. Pulmonary barotrauma (PBt) of ascent is also known as pulmonary over-inflation syndrome (POIS), lung over-pressure injury (LOP) and burst lung. Consequent injuries may include arterial gas embolism, pneumothorax, mediastinal, interstitial and subcutaneous emphysemas, depending on where the gas ends up, not usually all at the same time. POIS may also be caused by mechanical ventilation.
Bioarchaeology has helped to dispel the idea that life for foragers of the past was "nasty, brutish and short"; bioarchaeological studies reported that foragers of the past were often healthy, while agricultural societies tended to have increased incidence of malnutrition and disease. One study compared foragers from Oakhurst to agriculturalists from K2 and Mapungubwe and reported that agriculturalists from K2 and Mapungubwe were not subject to the lower nutritional levels expected. Danforth argues that more "complex" state-level societies display greater health differences between elites and the rest of society, with elites having the advantage, and that this disparity increases as societies become more unequal. Some status differences in society do not necessarily mean radically different nutritional levels; Powell did not find evidence of great nutritional differences between elites and commoners, but did find lower rates of anemia among elites in Moundville. An area of increasing interest interested in understanding inequality is the study of violence. Researchers analyzing traumatic injuries on human remains have shown that social status and gender can have a significant impact on exposure to violence. Numerous researchers study violence in human remains, exploring violent behavior, including intimate partner violence, child abuse, institutional abuse, torture, warfare, human sacrifice, and structural violence.
A 2012 study published in the Skeptical Inquirer examined the grants and awards funded by NCCIH from 2000 to 2011, which totaled $1.3 billion. The study found no discoveries in complementary and alternative medicine that would justify the existence of this center. The authors argued that after 20 years and an expenditure of $2 billion, the failure of NCCIH was evidenced by the lack of publications and the failure to report clinical trials in peer-reviewed medical journals. They recommended that NCCIH be defunded or abolished and the concept of funding alternative medicine be discontinued. In 2019, an analysis by the Center for Inquiry found that NCCIH was continuing to fund questionable science and that "there is little hope of reforming the NCCIH as it is currently incorporated". It concluded that "There is no legitimate function that the NCCIH can serve that could not be better carried out by other existing organizations within the NIH umbrella." Writing for Quackwatch in 2023, William London criticized the NCCIH and its article "6 Things To Know When Selecting a Complementary Health Practitioner" for "misleading consumers" and promoting—rather than warning against—complementary health, which "is often a euphemism for quackery."
Abelacimab (MAA868), is a fully human monoclonal antibody for the treatment of thrombosis, under development by Anthos Therapeutics. It is anti-factor XI antibody. The hope behind its development is that factor XI plays a bigger role in thrombosis (via the intrinsic/contact activation pathway) than hemostasis, so targeting it might reduce clotting risks without a corresponding increase in bleeding. It has, indeed, shown overwhelming reduction in bleeding as compared to a direct oral anticoagulant (rivaroxaban) in patients with atrial fibrillation and a moderate-to-high risk of stroke. Data is insufficient for drawing a conclusion on whether it increases or decreases stroke events as compared to rivaroxaban. Antibody Monoclonal antibody Immunology
A much larger effect comes from above-ground nuclear testing, which released large numbers of neutrons into the atmosphere, resulting in the creation of 14C. From about 1950 until 1963, when atmospheric nuclear testing was banned, it is estimated that several tonnes of 14C were created. If all this extra 14C had immediately been spread across the entire carbon exchange reservoir, it would have led to an increase in the 14C/12C ratio of only a few per cent, but the immediate effect was to almost double the amount of 14C in the atmosphere, with the peak level occurring in 1964 for the northern hemisphere, and in 1966 for the southern hemisphere. The level has since dropped, as this bomb pulse or "bomb carbon" (as it is sometimes called) percolates into the rest of the reservoir.
Sources: en.wikipedia.org
It is a synthetic compound studied as an agonist of REV-ERB nuclear receptors. It is not an approved medicine and has mainly been examined in laboratory and animal research.
No. It is a small molecule that binds nuclear receptors involved in circadian regulation. Its classification differs from anabolic steroids or peptide hormones.
Published human clinical trial data are lacking. Most safety and activity information comes from preclinical models, so effects in people remain uncertain.
It is usually detected by LC-MS or HPLC-UV against a reference standard. In biological matrices, metabolite targeting can improve detection. No universal immunoassay is widely available.