A practical reference on monohydrate: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-05-01. Anything still debated is marked as such rather than presented as settled.
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.
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.
The compound was identified in the nineteenth century after chemists isolated a nitrogenous substance from meat extracts. Later work established its role in muscle energy metabolism and its conversion to phosphocreatine. Chemical synthesis of creatine followed, and industrial production made the monohydrate widely available as a purified powder. Interest expanded in the late twentieth century when researchers began studying creatine supplementation and muscle physiology. Historical accounts sometimes differ on exact dates and attributions, but the broad sequence from tissue extracts to synthetic production is well documented.
In the body, creatine is obtained from dietary meat and fish and is also synthesized from arginine, glycine, and methionine. Muscle stores creatine and phosphocreatine, which participate in the rapid regeneration of adenosine triphosphate during short, intense activity. The monohydrate form is used in research because it is chemically defined, stable as a dry solid, and relatively inexpensive to produce. Questions remain about whether other creatine forms offer meaningful advantages in absorption or tissue retention, and findings vary across studies and populations.
| 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. |
Commercial creatine products appear in several forms, including monohydrate, hydrochloride, citrate, nitrate, and ethyl ester. Creatine monohydrate is the most studied form and serves as a reference material in comparative research. Different forms vary in solubility, pH, and water content, but they share creatine as the active moiety after dissolution. Claims that one form is uniformly superior remain debated, and study designs often differ in population, exercise protocol, and outcome measures. Purity and hydration state are central to interpreting product labels.
Creatine monohydrate is the hydrated form of creatine, a nitrogen-containing organic acid involved in cellular energy transfer. Its molecular formula is C4H11N3O3, and it consists of creatine plus one water molecule in the crystal lattice. The anhydrous base, creatine, has the formula C4H9N3O2. The compound appears as a white, odorless, crystalline powder and is classified as a guanidine derivative. It is distinct from creatinine, a breakdown product measured in clinical chemistry.
Analytical methods for creatine monohydrate focus on identity, purity, and degradation products. High-performance liquid chromatography with ultraviolet detection is common, often at a wavelength near 210 nanometers. Titration and nuclear magnetic resonance spectroscopy can also quantify the parent compound. Pharmacopeial monographs specify tests for appearance, solubility, water content, and related substances, including creatinine. Purity values above 99 percent are typical for pharmaceutical-grade material, though supplement-grade products vary. Independent verification can detect label discrepancies.
Sourcing and verification of creatine monohydrate involve both manufacturing origin and third-party testing. Industrial production commonly starts with sarcosine and cyanamide, followed by crystallization to obtain the monohydrate. Some products are derived from animal sources, while others are synthesized from non-animal precursors. Certificates of analysis report assay, heavy metals, and microbial limits. Regulations differ by country: in the United States it is sold as a dietary supplement, whereas in the European Union it falls under food supplement rules.
Bacteria can also eventually become resistant, through systems like CRISPR/Cas9 system. Many clinical trials have been promising though, showing that it could potentially help with the antimicrobial resistance problem. It can also be used in conjunction with antibiotics for a cumulative effect. Medical microbiology is not only about diagnosing and treating disease, it also involves the study of beneficial microbes. Microbes have been shown to be helpful in combating infectious disease and promoting health. Treatments can be developed from microbes, as demonstrated by Alexander Fleming's discovery of penicillin as well as the development of new antibiotics from the bacterial genus Streptomyces among many others. Not only are microorganisms a source of antibiotics but some may also act as probiotics to provide health benefits to the host, such as providing better gastrointestinal health or inhibiting pathogens.
Respiratory stimulants: carotid chemoreceptor agonists (e.g. doxapram), 5-HT4 agonists (e.g. BIMU8), δ-opioid agonists (e.g. BW373U86) and AMPAkines (e.g. CX717) can all reduce respiratory depression caused by opioids without affecting analgesia, but most of these drugs are only moderately effective or have side effects which preclude use in humans. 5-HT1A agonists such as 8-OH-DPAT and repinotan also counteract opioid-induced respiratory depression, but at the same time reduce analgesia, which limits their usefulness for this application. Opioid antagonists (e.g. naloxone, nalmefene, diprenorphine) The initial 24 hours after opioid administration appear to be the most critical with regard to life-threatening OIRD, but may be preventable with a more cautious approach to opioid use. Patients with cardiac, respiratory disease and/or obstructive sleep apnoea are at increased risk for OIRD.
Selegiline, also known as L-deprenyl and sold under the brand names Eldepryl, Zelapar, and Emsam among others, is a medication which is used in the treatment of Parkinson's disease and major depressive disorder. It has also been studied and used off-label for a variety of other indications, but has not been formally approved for any other use. The medication, in the form licensed for depression, has modest effectiveness for this condition that is similar to that of other antidepressants. Selegiline is provided as a swallowed tablet or capsule or an orally disintegrating tablet (ODT) for Parkinson's disease and as a patch applied to skin for depression. Side effects of selegiline occurring more often than with placebo include insomnia, dry mouth, dizziness, anxiety, abnormal dreams, and application site reactions (with the patch form), among others. At high doses, selegiline has the potential for dangerous food and drug interactions, such as tyramine-related hypertensive crisis (the so-called "cheese reaction") and risk of serotonin syndrome. However, doses within the approved clinical range appear to have little to no risk of these interactions. In addition, the ODT and transdermal patch forms of selegiline have reduced risks of such interactions compared to the conventional oral form. Selegiline has no known misuse potential or dependence liability and is not a controlled substance except in Japan. Selegiline acts as a monoamine oxidase inhibitor (MAOI) and thereby increases levels of monoamine neurotransmitters in the brain.
A study of proteins in cerebrospinal fluid indicates there are five subtypes of Alzheimer's disease, suggesting it to be likely that subtype-specific treatments are required. A study finds seaweed farming could be set up as a resilient food solution within roughly a year in abrupt sunlight reduction scenarios such as after a nuclear war or a large volcano eruption. 10 January Chemists report studies finding that long-chain fatty acids were produced in ancient hydrothermal vents. Such fatty acids may have contributed to the formation of the first cell membranes that are fundamental to protocells and the origin of life. Scientists report the extinction of Gigantopithecus blacki, the largest primate to ever inhabit the Earth, that lived between 2 million and 350,000 years ago, was largely due to the inability of the ape to adapt to a diet better suited to a significantly changed environment. 11 January Biologists report the discovery of the oldest known skin, fossilized about 289 million years ago, and possibly the skin from an ancient reptile. Scientists report the discovery of Tyrannosaurus mcraeensis, an older species of Tyrannosaurus that lived 5-7 million years before Tyrannosaurus rex, and which may be fundamentally important to the evolution of the species. A study of the Caatinga region in Brazil finds that its semi-arid biome could lose over 90% of mammal species by 2060, even in a best-case scenario of climate change.
Sources: en.wikipedia.org
=== Multiple turns === In many cases, one or more residues are involved in two partially overlapping turns. For example, in a sequence of 5 residues, both residues 1 to 4 and residues 2 to 5 form a turn; in such a case, one speaks of an (i, i + 1) double turn. Multiple turns (up to sevenfold) occur commonly in proteins. Beta bend ribbons are a different type of multiple turn. Multiple types of short H-bonded loop motifs are composed of overlapping H-bonded turns of the same or different types (lengths), including the Schellman loop and its variants, the multiple types of the beta bulge loop, and others. These motifs, which play key roles in proteins, including as helix caps, chain-reversers in beta hairpins and ligand binders, have been described as "compound turns" and classified using a compact notation that specifies the types and start positions in the loop of each motif's turns. The ExploreTurns tool supports the exploration and analysis of these motifs. The tool may also be used to explore individual H-bonded turns of all types.
==== United Kingdom ==== During the 1980s, 7-Eleven convenience stores were based in London and the South East of England. The first shop opened in Hendon, north London in 1985. In October 1997 all 57 UK 7-Eleven stores were sold to Budgens. The company announced in 2014 they had planned to return to the UK market, but this did not progress beyond its announcement. In 2019, the company announced again it had planned to return, but as of October 2022 no stores had been opened.
Fricasé is a traditional soup in Bolivian cuisine prepared with pork, pork ribs or chicken, hominy, chuño (a freeze-dried potato product) or potatoes, onion, garlic, salt, pepper and spices. It is sometimes consumed as a hangover food, as having a theoretical potential for easing or alleviating symptoms associated with the hangover. Fricasé is a common soup in Bolivia, and is often sold and consumed in the morning. It is a spicy soup that is typically prepared using large chunks of meat, and chuno potatoes are typically used in the Altiplano region of Bolivia. The aji pepper is sometimes used as an ingredient, and bread crumbs are sometimes used to thicken the soup.
== Precision and uncertainties == The precision to which a molar mass is known depends on the precision of the atomic masses from which it was calculated (and very slightly on the value of the molar mass constant, which depends on the measured value of the dalton). Most atomic masses are known to a precision of at least one part in ten-thousand, often much better (the atomic mass of lithium is a notable, and serious, exception). This is adequate for almost all normal uses in chemistry: it is more precise than most chemical analyses, and exceeds the purity of most laboratory reagents. The precision of atomic masses, and hence of molar masses, is limited by the knowledge of the isotopic distribution of the element. If a more accurate value of the molar mass is required, it is necessary to determine the isotopic distribution of the sample in question, which may be different from the standard distribution used to calculate the standard atomic mass. The isotopic distributions of the different elements in a sample are not necessarily independent of one another: for example, a sample which has been distilled will be enriched in the lighter isotopes of all the elements present. This complicates the calculation of the standard uncertainty in the molar mass. A useful convention for normal laboratory work is to quote molar masses to two decimal places for all calculations. This is more accurate than is usually required, but avoids rounding errors during calculations. When the molar mass is greater than 1000 g/mol, it is rarely appropriate to use more than one decimal place.
S100 calcium-binding protein B (S100B) is a protein of the S100 protein family. S100 proteins are localized in the cytoplasm and nucleus of a wide range of cells, and involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation. S100 genes include at least 13 members which are located as a cluster on chromosome 1q21; however, this gene is located at 21q22.3.
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.
It is a crystalline form of creatine that contains one water molecule per creatine molecule. The compound occurs naturally in muscle tissue and is also produced synthetically for research and consumer products. The monohydrate label describes the solid's hydration state.