If you have been reading about freeze-thaw cycle 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.
Last reviewed on 2026-03-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
Storage recommendations for SR9009 reference material typically specify a freezer at -20 °C or lower, with protection from moisture and light. Repeated freeze-thaw cycles can degrade small molecules and introduce variability. Stock solutions in dimethyl sulfoxide are often aliquoted to avoid repeated handling. Stability studies may examine degradation under heat, humidity, and light exposure. The compound's thiophene and nitro groups can participate in reactions that alter analytical signals over time, so such changes affect quantitative results.
Quality control for research materials includes identity confirmation by nuclear magnetic resonance and purity assessment by high-performance liquid chromatography. Mass spectrometry provides molecular weight confirmation and can detect related impurities. Purchasers should request a certificate of analysis that lists lot-specific data. Online products advertised for human use often lack such documentation. Distinguishing legitimate research material from mislabeled or contaminated samples is a recurring challenge in independent testing, and independent laboratories may use orthogonal methods to verify identity.
Because REV-ERB receptors are core clock components, SR9009 has been examined for effects on daily rhythms as well as metabolism. Research has explored whether the compound can shift or reinforce circadian gene expression in tissues such as liver and muscle. Some studies report improved metabolic markers in obese or diabetic mice, while others show context-dependent responses. Questions remain about which effects are direct, which are secondary to timing, and how they might differ across species.
SR9009 is a synthetic small molecule studied as an agonist of REV-ERB nuclear receptors. REV-ERB alpha and REV-ERB beta help regulate circadian rhythms and metabolic gene expression. In laboratory research, SR9009 has been used to probe how these receptors affect skeletal muscle, liver, and adipose tissue. The compound was identified in academic drug-discovery work and is often described in scientific literature by its chemical name and research code. It is not an approved medicine, and human clinical data remain limited or absent.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | -20 °C or lower | Desiccated and protected from light |
| Common analytical method | LC-MS/MS | Detects parent drug and metabolites |
| Solubility class | Lipophilic; soluble in organic solvents | Low aqueous solubility |
| Molecular weight | 437.94 g/mol | Calculated from reported formula |
| Synonyms | SR9009; REV-ERB agonist | Code name used in scientific literature |
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.
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.
Physicochemical behavior influences handling. SR9009 is described as a solid with limited aqueous solubility, so organic solvents such as dimethyl sulfoxide or ethanol are common in research stock solutions. Aqueous dilution can produce precipitates if the organic content is too low. Light, heat, and repeated freeze-thaw cycles may affect stability. Storage recommendations usually specify a desiccated freezer environment protected from light, but exact stability data depend on the formulation and matrix.
Research interest in SR9009 grew from studies of circadian biology and metabolic disease. Preclinical reports describe effects on exercise capacity, muscle metabolism, and blood lipid levels in rodents, but these findings come from controlled laboratory settings. The compound has low oral bioavailability in animals, which limits systemic exposure after swallowing. Investigators often use injected routes in experiments to achieve measurable plasma concentrations. Human clinical data are sparse, no approved therapeutic product exists, and whether animal effects translate to humans remains an open question.
Regulatory and sporting contexts treat SR9009 as a prohibited substance in many elite competitions. Its presence on banned lists reflects concerns about performance enhancement and unknown long-term safety. Analytical chemists have developed methods to detect the parent compound and its metabolites in urine and blood. Literature discussions distinguish between in vitro potency, animal pharmacology, and anecdotal human reports. The latter are difficult to verify because products sold online may lack purity or contain different compounds.
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, lipid metabolism, and inflammatory gene expression. In cell and animal experiments, SR9009 alters transcription of clock-controlled genes and metabolic pathways. The compound is not a hormone and does not resemble classical steroid structures. Its activity depends on binding to the ligand-binding domain of REV-ERB, where it can modify corepressor recruitment.
Mode I – Opening mode (a tensile stress normal to the plane of the crack), Mode II – Sliding mode (a shear stress acting parallel to the plane of the crack and perpendicular to the crack front), and Mode III – Tearing mode (a shear stress acting parallel to the plane of the crack and parallel to the crack front). When the size of the plastic zone at the crack tip is too large, elastic-plastic fracture mechanics can be used with parameters such as the J-integral or the crack tip opening displacement. The characterising parameter describes the state of the crack tip which can then be related to experimental conditions to ensure similitude. Crack growth occurs when the parameters typically exceed certain critical values. Corrosion may cause a crack to slowly grow when the stress corrosion stress intensity threshold is exceeded. Similarly, small flaws may result in crack growth when subjected to cyclic loading. Known as fatigue, it was found that for long cracks, the rate of growth is largely governed by the range of the stress intensity
=== Nervous system === Chronic pain can be divided into three categories. Nociceptive pain is pain caused by inflammation or damage to tissues. Neuropathic pain is pain caused by nerve damage. Nociplastic pain (or central sensitization) is less understood and is the common explanation of the pain experienced in fibromyalgia. Because the three forms of pain can overlap, fibromyalgia patients may experience nociceptive (e.g., rheumatic illnesses) and neuropathic (e.g., small fiber peripheral neuropathy) pain in addition to nociplastic pain.
==== Conditions for higher transfer results ==== Nearly complete transfer in systems implementing countercurrent exchange, is only possible if the two flows are, in some sense, "equal". For a maximum transfer of substance concentration, an equal flowrate of solvents and solutions is required. For maximum heat transfer, the average specific heat capacity and the mass flow rate must be the same for each stream. If the two flows are not equal, for example if heat is being transferred from water to air or vice versa, then, similar to cocurrent exchange systems, a variation in the gradient is expected because of a buildup of the property not being transferred properly.
Potter (1842), officer during the American Civil War Augustus van Horne Ellis* (1844), Civil War general William Cutting* (1851), lawyer and soldier Henry Eugene Davies (1857), Civil War general William McNeill Whistler* (1857), Confederate soldier and surgeon, brother of James Abbott McNeill Whistler Alfred Thayer Mahan* (1858), president, U.S. Naval War College and author of The Influence of Sea Power Upon History William Jay (1859), soldier and lawyer, 40th president of the Saint Nicholas Society of the City of New York and great-grandson of first U.S. chief justice John Jay Alister Greene (1875), soldier and leader during the Gilded Age Duncan Elliot (1884), soldier and banker Hamilton Fish II (1895), first American killed in the Spanish–American War Ulysses S. Grant III* (1902), grandson of Ulysses S. Grant, entered with the class of 1902 but transferred to United States Military Academy Donald Armstrong (1909), brigadier general and commandant of the Army Industrial College John H. Hilldring* (1916), U.S. major general and former assistant secretary of state for occupied areas Melvin Krulewitch (1916), U.S. major general and president of the New York State Athletic Commission John F. "Jack" Hasey* (1940), American captain in the French Foreign Legion; recipient of the Order of Liberation
== United Kingdom == The Public Health Laboratory Service (PHLS) was established as part of the National Health Service in 1946. An Emergency Public Health Laboratory Service was established in 1940 as a response to the threat of bacteriological warfare. There was originally a central laboratory at Colindale and a network of regional and local laboratories. By 1955 there were about 1000 staff. These laboratories were primarily preventive with an epidemiological focus. They were, however, in some places located with hospital laboratories which had a diagnostic focus. The PHLS was replaced by the Health Protection Agency in 2003; the HPA was disbanded and in its stead was constituted Public Health England, which later became the UK Health Security Agency in 2021.
Sources: en.wikipedia.org
=== Journals === ACS Chemical Biology – The new Chemical Biology journal from the American Chemical Society. Bioorganic & Medicinal Chemistry – The Tetrahedron Journal for Research at the Interface of Chemistry and Biology ChemBioChem – A European Journal of Chemical Biology Chemical Biology – A point of access to chemical biology news and research from across RSC Publishing Cell Chemical Biology – An interdisciplinary journal that publishes papers of exceptional interest in all areas at the interface between chemistry and biology. chembiol.com Journal of Chemical Biology – A new journal publishing novel work and reviews at the interface between biology and the physical sciences, published by Springer. link Journal of the Royal Society Interface – A cross-disciplinary publication promoting research at the interface between the physical and life sciences Molecular BioSystems – Chemical biology journal with a particular focus on the interface between chemistry and the -omic sciences and systems biology. Nature Chemical Biology – A monthly multidisciplinary journal providing an international forum for the timely publication of significant new research at the interface between chemistry and biology. Wiley Encyclopedia of Chemical Biology link
Tyrannosaurus is the most widely known dinosaur in popular culture. Science writer Riley Black states, "In all of prehistory, there is no animal that commands our attention quite like Tyrannosaurus rex... Since the time this dinosaur was officially named in 1905, the enormous carnivore has stood as the ultimate dinosaur." Paleontologist David Hone notes the popularity of Tyrannosaurus models and skeletal displays in museums and writes that films like Jurassic Park and King Kong "would not have been the same without it." T. rex is the only dinosaur that is commonly known to the general public by its full scientific name (binomial name) and the scientific abbreviation T. rex has also come into wide usage.
== Function == GPVI is a 58-kD platelet membrane glycoprotein that plays a crucial role in the collagen-induced activation and aggregation of platelets. Upon injury to the vessel wall and subsequent damage to the endothelial lining, exposure of the subendothelial matrix to blood flow results in deposition of platelets. Collagen fibers are the most thrombogenic macromolecular components of the extracellular matrix, with collagen types I, III, and VI being the major forms found in blood vessels. Platelet interaction with collagen occurs as a 2-step procedure: (1) the initial adhesion to collagen is followed by (2) an activation step leading to platelet secretion, recruitment of additional platelets, and aggregation. In physiologic conditions, the resulting platelet plug is the initial hemostatic event limiting blood loss. However, exposure of collagen after rupture of atherosclerotic plaques is a major stimulus of thrombus formation associated with myocardial infarction or stroke. Complete or partial deficiency of GPVI in humans is a rare condition presenting as a mild bleeding disorder.
== Clinical significance == Proline hydroxylation requires ascorbic acid (vitamin C). The most obvious, first effects (gingival and hair problems) of absence of ascorbic acid in humans come from the resulting defect in hydroxylation of proline residues of collagen, with reduced stability of the collagen molecule, causing scurvy. Increased serum and urine levels of hydroxyproline have also been demonstrated in Paget's disease. Mass spectrometry analysis showed decreased amount of hydroxyproline post-translational modifications in non inflamed tissue from ulcerative colitis patients when compared to tissue from donors without the disease.
Sources: en.wikipedia.org
=== Collagen synthesis === An injury does not become a scar until the wound has completely healed; this can take many months, or years in the worst pathological cases, such as keloids. To begin to patch the damage, a clot is created; this clot is the beginning process that results in a provisional matrix. In the process, the first layer is a provisional matrix and is not a scar. Over time, the wounded body tissue overexpresses collagen inside the provisional matrix to create a collagen matrix. This collagen overexpression continues and crosslinks the fiber arrangement inside the collagen matrix, making the collagen dense. This densely packed collagen, morphing into an inelastic whitish collagen scar wall, blocks off cell communication and regeneration; as a result, the new tissue generated will have a different texture and quality than the surrounding unwounded tissue. This prolonged collagen-producing process results in a fortuna scar.
Controlled collagen turnover is crucial for embryonic development, organ morphogenesis, as well as tissue maintenance and repair. However, changes of collagen homeostasis are associated with numerous diseases and pathological conditions. Excessive collagen degradation may be associated with cancer metastasis, skin ageing, arthritis, and osteoporosis. CHPs can target tissues undergoing remodelling based on their ability to bind to degraded and unfolded collagen strands through triple helix formation. As a targeting moiety, CHPs offer great potential in histopathology, diagnostics, and drug delivery for a wide range of diseases. Most methods for the evaluation of collagen denaturation in disease states are indirect, such as detecting matrix metalloproteinase (MMP) activity or quantifying collagen peptide fragments in urine, serum, or synovial fluid. Using conventional methods for directly targeting collagen, researchers have to relied on collagen binding peptides selected by phage display, derived from collagen binding proteins, or antibodies raised against collagens. Unfortunately, these compounds cannot target denatured collagens which are unstructured and do not present a defined 3D epitope. In addition, antibodies that were reported to distinguish specific degraded collagen fragments can only recognize one or few collagen types. In contrast, CHPs, in principle, can bind to all types of denatured collagens.
=== Heritable connective tissue disorders === Hereditary connective tissue disorders are a diverse set of broad, single-gene disorders that impact one or more of the main components of connective tissues, such as ground substance (glycosaminoglycans), collagen, or elastin. Many result in anomalies of the skeleton and joints, which can substantially impair normal growth and development. In contrast to acquired connective tissue diseases, these conditions are uncommon.
Sources: en.wikipedia.org
Liquid chromatography-tandem mass spectrometry is a common approach. It can detect the parent compound and its metabolites in biological matrices.
Research samples are typically kept frozen, desiccated, and protected from light. Stock solutions are often aliquoted to reduce freeze-thaw cycles.
High-performance liquid chromatography and nuclear magnetic resonance are standard for purity and identity. Mass spectrometry confirms molecular weight.
SR9009 is a synthetic research compound that acts on REV-ERB nuclear receptors. It is not approved for human use and is sold only as a research chemical. Its effects have been studied mainly in cells and rodents.