bioavailability 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 2025-09-19. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Regulatory treatment of SR9009 varies by country and region. It is not approved as a pharmaceutical, and several jurisdictions restrict its sale for human consumption. Some authorities classify it as a research chemical, a prescription-only substance, or a prohibited performance-enhancing agent in sport. Purchasers may encounter certificates of analysis, but these documents do not guarantee identity, purity, or legality. In research settings, institutional safety reviews and controlled procurement help ensure that materials are handled under appropriate oversight. The absence of harmonized rules means that legal status can change and requires verification.
Analytical identification of SR9009 typically relies on liquid chromatography coupled with tandem mass spectrometry. In biological samples, researchers first separate the compound from matrix components using protein precipitation, liquid-liquid extraction, or solid-phase extraction. High-performance liquid chromatography with ultraviolet detection and nuclear magnetic resonance spectroscopy can support structural confirmation of reference materials. Because SR9009 is a small, relatively lipophilic molecule, reverse-phase columns and acidic mobile phases are common. Laboratories often include isotope-labeled internal standards to improve quantification and to correct for ion suppression.
Stability depends on physical form, temperature, light exposure, and solvent. Solid SR9009 is generally stored cold and dry, with protection from light to limit degradation. Dimethyl sulfoxide stocks are common for laboratory work, but repeated freeze-thaw cycles can reduce compound integrity. Aqueous solutions may be less stable than organic stocks, and the ethyl ester in the structure can be susceptible to hydrolysis under certain conditions. Researchers typically validate storage conditions and recheck purity before quantitative experiments, especially when using archived material.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C20H24ClN3O4S | Reported for the free base |
| Molecular weight | 437.9 g/mol | Calculated from the formula |
| Primary target | REV-ERBα and REV-ERBβ | Nuclear receptors involved in circadian regulation |
| Solubility | Soluble in DMSO and ethanol | Poorly soluble in water |
| Typical storage | -20 °C, desiccated | Protect from light and moisture |
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.
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.
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.
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.
== Further reading == Hunt, Chris; et al. (August 28, 2023). "Shanidar et ses fleurs? Reflections on the palynology of the Neanderthal 'Flower Burial' hypothesis". Journal of Archaeological Science. 159 105822. Bibcode:2023JArSc.159j5822H. doi:10.1016/j.jas.2023.105822. S2CID 261325698. Pettitt, Paul; White, Mark (2012). The British Palaeolithic: hominin societies at the edge of the Pleistocene world. London: Routledge. ISBN 978-0-415-67454-6. Romagnoli, Francesca; Rivals, Florent; Benazzi, Stefano (2022). Updating Neanderthals: Understanding Behavioural Complexity in the Late Middle Palaeolithic. Academic Press. ISBN 978-0-12-821429-9. Stringer, C.; Gamble, C. (1993). In search of the Neanderthals. Thames and Hudson. ISBN 0-500-05070-8. Sykes, Rebecca Wragg (2020). Kindred: Neanderthal Life, Love, Death and Art. London: Bloomsbury Sigma. ISBN 978-1-4729-3749-0.
== Development == The usual development of CAD is when a cool high-pressure area wedges in east of a north-south oriented mountain chain. As a system approaches from the west, a persistent cloud deck with associated precipitation forms and lingers across the region for prolonged periods of time. Temperature differences between the warmer coast and inland sections east of the terrain can exceed 36 degrees Fahrenheit (20 degrees Celsius), with rain near the coast and frozen precipitation, such as snow, sleet, and freezing rain, falling inland during colder times of the year. In the Northern Hemisphere, two-thirds of such events occur between October and April, with summer events preceded by the passage of a backdoor cold front. In the Southern Hemisphere, they have been documented to occur between June and November. Cold air damming events which occur when the parent surface high-pressure system is relatively weak, with a central pressure below 1,028.0 millibars (30.36 inHg), or remaining a progressive feature (move consistently eastward), can be significantly enhanced by cloudiness and precipitation itself. Clouds and precipitation act to increase sea level pressure in the area by 1.5 to 2.0 mb ( 0.04 to 0.06 inHg). When the surface high moves offshore, the precipitation itself can cause the CAD event.
Most large submarines consist of a cylindrical body with hemispherical (or conical) ends and a vertical structure, usually located amidships, which houses communications and sensing devices as well as periscopes. In modern submarines, this structure is called the "sail" in American usage and "fin" in European usage. A feature of earlier designs was the "conning tower": a separate pressure hull above the main body of the boat that enabled the use of shorter periscopes. There is a propeller (or pump jet) at the rear, and various hydrodynamic control fins. Smaller, deep-diving, and specialty submarines may deviate significantly from this traditional design. Submarines dive and resurface by using diving planes and by changing the amount of water and air in ballast tanks to affect their buoyancy. Submarines encompass a wide range of types and capabilities. They range from small, autonomous examples, such as one- or two-person subs that operate for a few hours, to vessels that can remain submerged for six months, such as the Russian Typhoon class (the biggest submarines ever built). Submarines can work at depths that are greater than what is practicable (or even survivable) for human divers. More countries are building and operating submarines today than ever before in modern history, and China is leading the construction surge.
Black Mesa is a 2020 first-person shooter video game developed and published by Crowbar Collective. It is a fan-made remake of Half-Life (1998) in the Source game engine. Originally published as a free mod in September 2012, Black Mesa was approved for commercial release by Valve, the developers of Half-Life. The first commercial version was published as an early-access release in May 2015 with an abridged campaign, followed by a full release in March 2020 restoring the final chapters. Black Mesa was developed in response to Half-Life: Source (2004), Valve's port of Half-Life to the Source engine, which lacked new features or improvements over the original version that used GoldSrc. Two teams wanted to improve on the Source remake and eventually merged to become Crowbar Collective. The project was originally slated to release in 2009, but was pushed back significantly for quality reasons. Adapting Half-Life to an improved version of the Source engine and completely reworking the often-derided final 4 chapters of the game, set outside of the Black Mesa facility on the alien borderworld of Xen, lengthened the development efforts of the remake. Due to its long development time, the modification became notable for its delays on the status of its completion. Major changes include a reskinned collection of textures, models and NPCs, a longer runtime, altered level and puzzle designs, along with different enemy artificial intelligence, and additional dialogue and story elements.
Never was there such a dame school as ours, so firm and kind and smelling of galoshes, with the sweet and fumbled music of the piano lessons drifting down from upstairs to the lonely schoolroom, where only the sometimes tearful wicked sat over undone sums, or to repent a little crime – the pulling of a girl's hair during geography, the sly shin kick under the table during English literature.
Sources: en.wikipedia.org
The 2nd Black Watch, with its Rhodesian contingent, took part in the unsuccessful Allied defence of Crete in May–June 1941, then joined the garrison at Tobruk in August 1941. No. 237 (Rhodesia) Squadron was re-equipped with Hawker Hurricanes the following month.
A large meta-analysis has shown that white adipose tissue cell size is dependent on measurement methods, adipose tissue depots, age, and body mass index; for the same degree of obesity, increases in fat cell size were also associated with the dysregulations in glucose and lipid metabolism.
In countercurrent flow, the two flows move in opposite directions. Two tubes have a liquid flowing in opposite directions, transferring a property from one tube to the other. For example, this could be transferring heat from a hot flow of liquid to a cold one, or transferring the concentration of a dissolved solute from a high concentration flow of liquid to a low concentration flow. The counter-current exchange system can maintain a nearly constant gradient between the two flows over their entire length of contact. With a sufficiently long length and a sufficiently low flow rate this can result in almost all of the property transferred. So, for example, in the case of heat exchange, the exiting liquid will be almost as hot as the original incoming liquid's heat.
{\displaystyle {\begin{aligned}\alpha _{{\ce {H2A}}}&={\frac {{\ce {[H+]^2}}}{{\ce {[H+]^2}}+[{\ce {H+}}]K_{1}+K_{1}K_{2}}}={\frac {{\ce {[H2A]}}}{{\ce {{[H2A]}}}+[HA^{-}]+[A^{2-}]}}\\\alpha _{{\ce {HA^-}}}&={\frac {[{\ce {H+}}]K_{1}}{{\ce {[H+]^2}}+[{\ce {H+}}]K_{1}+K_{1}K_{2}}}={\frac {{\ce {[HA^-]}}}{{\ce {[H2A]}}+{[HA^{-}]}+{[A^{2-}]}}}\\\alpha _{{\ce {A^{2-}}}}&={\frac {K_{1}K_{2}}{{\ce {[H+]^2}}+[{\ce {H+}}]K_{1}+K_{1}K_{2}}}={\frac {{\ce {[A^{2-}]}}}{{\ce {{[H2A]}}}+{[HA^{-}]}+{[A^{2-}]}}}\end{aligned}}}
=== Opposition front bencher: 1967–70 === In 1967, Peter Walker invited Heseltine to be opposition spokesman on transport (not a Shadow Cabinet-level position, but reporting to Walker), after he had arranged a successful speaking tour of the West Country for him. Heseltine's duties included opposing Barbara Castle's 1967 Transport Bill (which eventually became the Transport Act 1968). Heseltine led opposition to the parts of the bill which nationalised small bus companies into the National Bus Company (UK) and set up Passenger transport executives (PTEs) in major urban areas. He criticised Castle for wanting to give PTEs the right to manufacture or produce anything necessary for their function, which as she pointed out was almost word-for-word identical to a clause in the Conservatives' Transport Act 1962. In 1968 Margaret Thatcher became Heseltine's boss for a year; he found her "embarrassingly rude". Unusually for the time, he employed a full-time researcher, Eileen Strathnaver. Heath allowed his shadow ministers more leeway than would be normal nowadays. Heseltine was one of a group of 15 Conservative MPs to vote against the 1968 Commonwealth Immigration Bill on second reading (Conservative whips advised their MPs to support it, but it was a free vote). He also voted against the bill on three subsequent votes, arguing that it was based on "sheer naked racialism" and that Britain should honour promises previously made to the Kenyan Asians.
Sources: en.wikipedia.org
It is a synthetic REV-ERB agonist used mainly in preclinical research. It is not an approved medicine for human use.
It binds to REV-ERBα and REV-ERBβ, nuclear receptors involved in circadian and metabolic gene regulation. This can alter transcription of genes related to lipid and glucose metabolism in experimental models.
No controlled human trials have established that effect. Endurance findings come primarily from rodent studies, and human responses remain unknown.
The most common approach is liquid chromatography-tandem mass spectrometry, often after extraction from blood, urine, or tissue. Ultraviolet detection and nuclear magnetic resonance spectroscopy are used mainly for reference material characterization. Isotope-labeled internal standards improve accuracy.