If you have been reading about Zwitterion 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 2026-01-06. Where a claim depends on a specific study, the study is described rather than over-claimed.
Creatine monohydrate is a hydrated form of creatine, a nitrogen-containing compound involved in cellular energy metabolism. Its molecular formula is C4H9N3O2·H2O, with a molar mass around 149.15 g/mol. The monohydrate is the most common solid form used in research and commercial settings because it crystallizes readily and remains stable under ordinary conditions. The term monohydrate indicates one water molecule per creatine molecule in the crystal lattice. It appears as a white crystalline powder with low odor.
In the body, creatine is synthesized from arginine, glycine, and methionine, mainly in the liver and kidneys, and is also obtained from foods such as meat and fish. About 95% of body creatine is stored in skeletal muscle, where a fraction is phosphorylated to phosphocreatine. Phosphocreatine serves as a rapid reserve of high-energy phosphate for short bursts of ATP regeneration. The monohydrate form supplies creatine after dissolution and absorption, but it is not itself the active phosphorylated species.
Creatine was first identified in skeletal muscle extracts in the nineteenth century, and its role in phosphagen energy buffering was clarified in the twentieth century. The monohydrate salt became widely studied after methods for inexpensive synthesis and crystallization were developed. Modern research examines its effects on muscle energetics, recovery, and cognitive performance under specific conditions. Findings vary with population, exercise protocol, baseline creatine status, and measurement method. Studies often compare supplementation with placebo during controlled training or testing schedules.
Recommended storage usually involves a sealed container kept at room temperature, away from direct sunlight and moisture. High humidity can cause caking, which changes flow properties and may complicate accurate weighing. Repeated opening of containers exposes the powder to air and moisture, so smaller aliquots can reduce handling effects. Storage temperature ranges are not absolute requirements; they reflect conditions that slow degradation and preserve consistent physical characteristics. Clean, dry tools help prevent contamination during sampling.
Identity and purity are commonly assessed by high-performance liquid chromatography, often with ultraviolet detection, and by spectroscopic techniques such as infrared or nuclear magnetic resonance. These methods can distinguish creatine from creatinine and detect related impurities. Moisture content may be measured by Karl Fischer titration or loss on drying. Particle size, bulk density, and heavy metal limits are additional quality parameters. Not every product is tested by every method, so specifications depend on the intended use and regulatory framework.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C4H9N3O2·H2O | Creatine plus one water molecule in the crystal lattice. |
| Molar mass | 149.15 g/mol | Calculated for the monohydrate form. |
| Appearance | White crystalline powder | Typical solid form; particle size can vary by processing. |
| Solubility class | Sparingly soluble in water | Dissolution improves with time, stirring, and temperature. |
| Common synonyms | Creatine hydrate; N-carbamimidoyl-N-methylglycine monohydrate | Names vary by chemical registry and supplier. |
The term creatine monohydrate is often shortened to creatine in casual usage, though other creatine forms exist, including citrate, nitrate, and hydrochloride salts. These alternative forms differ in solubility, pH behavior, and the amount of creatine delivered per unit mass. Regulatory categories vary by country: some jurisdictions treat it as a food ingredient, while others place it under supplement or drug frameworks depending on claims and presentation. Standard reference texts list it as a naturally occurring nitrogenous organic acid rather than a vitamin or mineral.
Creatine monohydrate is a crystalline organic compound formed from creatine and water in a one-to-one ratio. It belongs to the guanidino family and contains a methylated guanidine group attached to an acetate-like chain. The solid is commonly described as a white, odorless powder with a mildly bitter taste. Its molecular formula is C4H11N3O3·H2O, and the hydrated form is the most widely traded grade. The compound occurs naturally in vertebrate muscle and brain tissue, where it participates in rapid energy buffering.
In aqueous solution, creatine monohydrate exists mainly as a zwitterion, carrying both a positive guanidinium charge and a negative carboxylate charge. This charge separation raises water solubility relative to many neutral organic solids and helps explain its behavior in analytical separations. The monohydrate can lose its water of crystallization under sustained heat or low humidity, converting toward anhydrous creatine. Such transitions matter for mass balance calculations because the hydrate contributes water mass that is not part of the active creatine molecule.
Analytical laboratories commonly identify creatine monohydrate by high-performance liquid chromatography with ultraviolet detection, often after dissolving the sample in water or dilute acid. Ion-exchange or reversed-phase columns separate creatine from creatinine and related guanidino compounds. Nitrogen content can be checked by Kjeldahl or combustion methods, while moisture is measured by Karl Fischer titration or loss on drying. These techniques give complementary views: chromatographic purity addresses related substances, whereas moisture and elemental data confirm hydrate stoichiometry. No single test defines quality by itself; a combination is used in specifications.
Storage recommendations generally emphasize a cool, dry place away from direct sunlight and strong oxidizers. Sealed containers limit humidity exchange, which helps prevent clumping and gradual conversion to creatinine. Long-term stability studies usually monitor appearance, moisture, and purity at intervals under defined temperature and humidity conditions. Accelerated tests at elevated temperature can reveal degradation pathways, but they do not perfectly predict room-temperature shelf life. Questions remain about how much creatinine formation is acceptable in different product categories and how packaging choices affect that rate over time.
Regulatory status varies by country. In the United States, creatine monohydrate is sold as a dietary supplement ingredient, while in the European Union it is placed on the market as a food supplement component. Some jurisdictions have established purity monographs or permitted health claims, while others treat it as a novel food or require notification. Product labels may state the amount of creatine monohydrate or the equivalent creatine content, and the two figures can differ. Independent testing programs sometimes check identity, potency, and contaminant limits.
Creatine monohydrate is stable under dry, cool conditions but can degrade when exposed to moisture and heat. In solution, it undergoes hydrolysis to creatinine, a cyclic derivative with little role in phosphagen energy transfer. The rate of conversion increases with temperature, storage time, and acidic or alkaline pH. Solid material kept in a sealed container at room temperature generally retains its composition for extended periods. Moisture uptake is a primary concern because it can accelerate breakdown and caking.
A number of analogues are known, with the only other well-known compound to come out of the original 1950s research being clonitazene, which is much weaker than etonitazene (around 3x morphine). More recently since around late 2018 a number of designer analogues have started to appear on illicit markets around the world, with the most prominent compounds being metonitazene, isotonitazene and etazene, though others have continued to appear. Of these analogues, only etonitazene and clonitazene are explicitly listed under UN conventions and so are controlled throughout the world. The rest would only be illegal in countries such as the US, Australia and New Zealand that have laws equivalent to the Federal Analog Act. In the United States Etonitazene is a Schedule I narcotic controlled substance with a DEA ACSCN of 9624 and a 25 gram (7⁄8 oz) manufacturing quota as of 2022.
== Occurrence == It occurs in tree fern fronds, a specialty called fiddlehead (furled fronds of a young tree fern in the order Cyatheales, harvested for use as a vegetable). These fronds are edible, but can be roasted to remove shikimic acid. Shikimic acid is also the glycoside part of some hydrolysable tannins. The acid is highly soluble in water and insoluble in nonpolar solvents, and this is why shikimic acid is active only against Gram-positive bacteria, due to outer cell membrane impermeability of Gram-negatives.
=== Psychological theories === The psychoanalytic theory model defines addiction as a form of defense against feelings of hopelessness and helplessness as well as a symptom of failure to regulate powerful emotions related to adverse childhood experiences (ACEs), various forms of maltreatment and dysfunction experienced in childhood. In this case, the addictive substance provides brief but total relief and positive feelings of control. Psychological contributions include learning and conditioning processes, impulsivity, reward sensitivity, and the use of substances to cope with negative mood or trauma. Conditioning models hold that environmental cues can acquire motivational significance of their own and trigger craving and relapse even after long periods of abstinence. Reviews of alcohol use disorder identify overvaluation of the drug's reinforcing effects, elevated impulsivity across several dimensions, the acute effects of stress and environmental triggers, and a lack of alternative rewarding activities as well-established psychological determinants, and present these processes as interacting with biological and social vulnerabilities, each reinforcing the others.
The metabolism of thiotepa primarily takes place in the liver, following both phase 1 and phase 2 metabolic pathways. Phase 1 involves reactions which change chemical moieties such as oxidation, reduction, and hydrolysis, while phase 2 includes the addition of endogenous groups to foreign compounds. Phase 1 metabolism of thiotepa is predominantly mediated by the cytochrome P450 enzyme system, major CYP2B6 and minor CYP3A4. In this phase an oxidation and desulfuration reactions convert thiotepa into its more active metabolite tepa. Tepa itself exhibits a longer plasma half-life (3 to 24 hours) than thiotepa (1 to 3 hours) and contributes to the overall pharmacological activity of the drug. In phase 2 thiotepa is detoxified via the conjugation with glutathione by glutathione S-transferase. This is followed by the removal of the glutamyl and glycine moieties, and concludes with the N-acetylation of the cysteine conjugate by N-acetylase to form thiotepa-mercapturate. This derivative is more water-soluble, facilitating urinary excretion. Tepa is not conjugated to glutathione but reacts further in the urine and plasma to monochloro tepa. The conversion to a β-chloroethyl moiety depends on the pH and the chloride concentration. The formation of monochloride tepa mainly occurs in the urine. Enzymes responsible for metabolising compounds can show varying efficiency in different individuals or populations, this is called polymorphism. In a study regarding thiotepa metabolism by Ekhart et al., it was found that glutathione S-transferase shows polymorphism.
Sources: en.wikipedia.org
=== External characteristics === The octopus has an elongated body that is bilaterally symmetrical along its dorso-ventral (back to belly) axis; the head and foot are on the ventral side, but act as the anterior (front). The head contains both the mouth and the brain. The mouth has a sharp chitinous beak and is surrounded by and underneath the foot, which evolved into flexible, prehensile limbs, known as "arms", which are attached to each other near their base by a webbed structure. The arms can be described based on side and sequence position (such as L1, R1, L2, R2) and divide into four pairs. The two rear appendages are generally used to walk on the sea floor, while the other six are used to forage for food. The bulbous and hollow mantle is fused to the back of the head and contains most of the vital organs. The mantle also has a cavity with muscular walls and a pair of gills; it is connected to the exterior by a funnel or siphon.
== Contraindications == Quinolones are not recommended in people with epilepsy, Marfan's syndrome, Ehlers–Danlos syndrome, QT prolongation, pre-existing CNS lesions, or CNS inflammation, or who have had a stroke. They are best avoided in the athlete population. Safety concerns exist for fluoroquinolone use during pregnancy, so they are contraindicated unless no other safe alternative antibiotic exists. However, one meta-analysis looking at the outcome of pregnancies involving quinolone use in the first trimester found no increased risk of malformations. They are also contraindicated in children due to the risks of damage to the musculoskeletal system. Their use in children is not absolutely contraindicated, however for certain severe infections where other antibiotics are not an option, their use can be justified. Quinolones should also not be given to people with a known hypersensitivity to the drug class. The basic pharmacophore, or active structure, of the fluoroquinolone class is based upon the quinoline ring system. The addition of the fluorine atom at C6 distinguishes the successive-generation fluoroquinolones from the first-generation of quinolones. The addition of the C6 fluorine atom has since been demonstrated not to be required for the antibacterial activity of this class (circa 1997).
In the absence of an effective enantiomeric environment (precursor, chiral catalyst, or kinetic resolution), separation of a racemic mixture into its enantiomeric components is impossible, although certain racemic mixtures spontaneously crystallize in the form of a racemic conglomerate, in which crystals of the enantiomers are physically segregated and may be separated mechanically. However, most racemates form crystals containing both enantiomers in a 1:1 ratio. In his pioneering work, Louis Pasteur was able to isolate the isomers of sodium ammonium tartrate because the individual enantiomers crystallize separately from solution. To be sure, equal amounts of the enantiomorphic crystals are produced, but the two kinds of crystals can be separated with tweezers. This behavior is unusual. A less common method is by enantiomer self-disproportionation. The second strategy is asymmetric synthesis: the use of various techniques to prepare the desired compound in high enantiomeric excess. Techniques encompassed include the use of chiral starting materials (chiral pool synthesis), the use of chiral auxiliaries and chiral catalysts, and the application of asymmetric induction. The use of enzymes (biocatalysis) may also produce the desired compound. A third strategy is enantioconvergent synthesis, the synthesis of one enantiomer from a racemic precursor, utilizing both enantiomers. By making use of a chiral catalyst, both enantiomers of the reactant result in a single enantiomer of product.
The first nonsteroidal androgens, the arylpropionamides, were discovered via structural modification of bicalutamide. Unlike bicalutamide (which is purely antiandrogenic), these compounds show tissue-selective androgenic effects and were classified as selective androgen receptor modulators (SARMs). Lead SARMs of this series included acetothiolutamide, enobosarm (ostarine; S-22), and andarine (acetamidoxolutamide or androxolutamide; S-4). They are very close to bicalutamide structurally, with the key differences being that the linker sulfone of bicalutamide has been replaced with an ether or thioether group to confer agonism of the AR and the 4-fluoro atom of the pertinent phenyl ring has been substituted with an acetamido or cyano group to eliminate reactivity at the position.
==== Human rights abuses and corruption ==== Building off the Global Magnitsky Human Rights Accountability Act, named after Sergei Magnitsky who died in Russian custody after uncovering corruption, the U.S. can enact sanctions against any individual or entity worldwide who it says engages in severe human rights abuses and corruption that degrade the rule of law, perpetuate violent conflicts, and facilitate the activities of dangerous persons. The following jurisdictions are frequently targeted by U.S. sanctions related to human rights abuses but are not specifically targeted under a country-specific sanctions program:
Sources: en.wikipedia.org
Partial smooth muscle differentiation of a fibroblastic cell Activation of a stellate cell (e.g. hepatic Ito cells or pancreatic stellate cells). Loss of contractile phenotype (or acquisition of "synthetic phenotype") of a smooth muscle cell. Direct myofibroblastic differentiation of a progenitor cell resident in a stromal tissue. Homing and recruitment of a circulating mesenchymal precursor which can directly differentiate as above or indirectly differentiate through the other cell types as intermediates. Epithelial to mesenchymal transdifferentiation (EMT) of an epithelial cell. Perhaps the most studied pathway of myofibroblast formation is TGF-beta1 dependent differentiation from fibroblast cells. Activation of the TGF-beta receptor 1 and TGF-beta receptor 2 leads to induction of the canonical SMAD2/SMAD3 pathway. Together with the co-activation of the non-canonical EGFR pathway, these events lead to upregulation of the ACTA2 gene and subsequent alpha smooth muscle actin protein production. Several regulators of the myofibroblast differentiation pathway have been described, including hyaluronan and CD44 co-receptor activation of EGFR.
=== Role in fetal development === CRH is not found in the oocytes of primordial follicles in normal human ovaries. However, there is a significant amount of CRH and its CRH-R1 gene expression in mature follicles . This suggests that CRH has auto/paracrine functions in the maturation of follicles. The level of CRH is greater in the ovaries of premenopausal women compared to postmenopausal women, indicating that ovarian CRH is associated with normal ovarian function throughout the reproductive lifespan.
Over its history as a food, the main uses of honey are in cooking, baking, desserts, as a spread on bread, as an addition to various beverages such as tea, and as a sweetener in some commercial beverages. Due to its energy density, honey is an important food for virtually all hunter-gatherer cultures in warm climates, with the Hadza people ranking honey as their favorite food. Honey hunters in Africa have a mutualistic relationship with certain species of honeyguide birds.
Grizard, G; Sion, B; Bauchart, D; Boucher, D (31 March 2000). "Separation and quantification of cholesterol and major phospholipid classes in human semen by high-performance liquid chromatography and light-scattering detection". Journal of Chromatography B: Biomedical Sciences and Applications. 740 (1): 101–7. doi:10.1016/S0378-4347(00)00039-6. PMID 10798299. SUNY Podcast – Semen study results Hyena, Hank (August 21, 2000). "The quest for sweet semen". Salon.
Sources: en.wikipedia.org
Creatine is the base compound, while creatine monohydrate is a solid crystalline form that contains one water molecule per creatine molecule. Once dissolved, the monohydrate dissociates and releases creatine, which can participate in cellular energy metabolism. The monohydrate is the form most commonly used in research and commercial products.
Meat and fish contain creatine, and the human body also synthesizes it from amino acids. The monohydrate form is not a natural food ingredient as such; it is a manufactured crystalline solid that provides creatine after ingestion. Food sources contribute to total body creatine stores alongside endogenous synthesis.
It means the crystal lattice includes one molecule of water for each molecule of creatine. This water is part of the solid's ordered structure, not bulk moisture. The hydrate form influences properties such as solubility, density, and shelf stability.
Solid product can remain within specification for years when stored dry and sealed, but expiration dates reflect manufacturer testing and regulatory conventions. Moisture and heat increase conversion to creatinine, so storage conditions matter more than the printed date alone. Degradation is gradual and can be monitored by purity testing.