If you have been reading about hygroscopicity 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.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
Creatine monohydrate is a crystalline compound formed when one molecule of creatine binds with one molecule of water. Creatine itself is a nitrogen-containing organic acid involved in cellular energy transfer, particularly in muscle and nerve tissue. The monohydrate form is the most common solid form used in research and commercial products because it is relatively stable and easy to handle. Its molecular formula is C4H9N3O2·H2O, and its molar mass is about 149.15 grams per mole.
In the human body, creatine is synthesized mainly in the liver and kidneys from the amino acids glycine, arginine, and methionine. Dietary sources include meat, fish, and other animal tissues, which supply preformed creatine. Because plant foods contain little or no creatine, dietary intake varies widely among populations. The compound is stored largely in skeletal muscle, where it is converted to phosphocreatine and used to regenerate adenosine triphosphate during short bursts of activity.
Creatine monohydrate is one of several solid forms of creatine described in the literature. Other forms include anhydrous creatine, creatine hydrochloride, and creatine ethyl ester, each with different solubility and stability characteristics. The monohydrate is distinct from creatinine, a spontaneous breakdown compound that forms when creatine loses water and cyclizes. Commercial descriptions sometimes use synonyms such as methylguanidoacetic acid or N-(aminoiminomethyl)-N-methylglycine, which refer to the same base molecule. These names appear in chemical databases and product labels.
In solid form, creatine monohydrate is relatively stable when kept dry and away from heat. Moisture and elevated temperatures promote cyclization into creatinine, a related compound with no role in the phosphagen system. Degradation accelerates in aqueous solution, where the conversion can occur within hours to days depending on pH and temperature. Manufacturers typically recommend storage in sealed containers at room temperature, with relative humidity below 50 percent. Long-term stability data for opened containers are limited.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C4H9N3O2·H2O | Monohydrate; anhydrous base is C4H9N3O2 |
| Molar mass | 149.15 g/mol | Calculated for the monohydrate form |
| Appearance | White crystalline powder | Typical laboratory and food-grade material |
| Solubility in water | Sparingly soluble at room temperature | Solubility increases with temperature |
| Common synonyms | Methylguanidoacetic acid; N-(aminoiminomethyl)-N-methylglycine | Synonyms refer to the creatine base, not the hydrate specifically |
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.
Analytical laboratories commonly use high-performance liquid chromatography to separate creatine from creatinine and related impurities. Ion chromatography, nuclear magnetic resonance, and titration assays can also quantify the compound. Water content is measured by Karl Fischer titration or loss on drying, because the monohydrate has a defined theoretical water fraction. Particle size, bulk density, and flowability are physical properties that affect blending and capsule filling. These measurements support quality control and help verify that a lot matches its specification.
Quality control of creatine monohydrate relies on a combination of identity, purity, and moisture tests. High-performance liquid chromatography with ultraviolet detection is widely used to separate creatine from creatinine and other related nitrogenous compounds. Spectroscopic methods such as infrared and nuclear magnetic resonance provide structural confirmation. Because the material is a hydrate, water content is measured separately, often by Karl Fischer titration. These tests together establish whether a lot meets a defined specification.
Manufacturing processes can leave trace amounts of dicyandiamide, creatinine, or residual solvents, depending on the synthetic route and purification steps. Heavy metals, arsenic, and microbial contamination are also monitored for food or pharmaceutical grades. Particle size distribution can affect dissolution behavior and blending uniformity, so it may be specified for certain applications. Analytical results are reported on a dry basis or as-is basis, and the difference matters when comparing certificates of analysis. Open questions remain about how minor impurities influence long-term stability under varied storage conditions.
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.
=== Democratizing access === Open-source allows countries and organizations that otherwise do not have access to proprietary models a way to use and invest in AI more cheaply. This can help to create an ecosystem for other businesses to sell services on top of.
=== Seed potatoes === Potatoes are generally grown from "seed potatoes"; that is to say, tubers specifically grown to be free from disease and to provide consistent and healthy plants. To be disease free, the areas where seed potatoes are grown are selected with care. In the US, this restricts production of seed potatoes to only 15 states out of all 50 states where potatoes are grown. These locations are selected for their cold, hard winters that kill pests and summers with long sunshine hours for optimum growth. In the UK, most seed potatoes originate in Scotland, in areas where westerly winds reduce aphid attacks and the spread of potato virus pathogens.
Most eukaryotic cellular mRNAs are blocked at their 5'-ends with the 7-methyl-guanosine five-prime cap structure, m7GpppX (where X is any nucleotide). eIF4E is a eukaryotic translation initiation factor that binds specifically to this cap structure. It is a 24-kD polypeptide that exists both in a free form and as part of the eIF4F pre-initiation complex. The other subunits of eIF4F are a 47-kD polypeptide, termed eIF4A, that possesses ATPase and RNA helicase activities, and a 220-kD scaffolding polypeptide, eIF4G. eIF4E is found in the nucleus of many mammalian cell types as well as in other species including yeast, drosophila and humans. eIF4E is found in nuclear bodies, some of which colocalize with PML nuclear bodies, and it also appears diffusely in the nucleoplasm.
Sources: en.wikipedia.org
=== Radiation offenses === The misuse of ionizing radiation is a radiation offence under German criminal law. The use of ionizing radiation to harm persons or property is punishable. Since 1998, the regulations can be found in § 309 StGB (in German) (previously § 311a StGB old version); the regulations go back to § 41 AtG old version. In the Austrian Criminal Code, relevant criminal offenses are defined in the seventh section, "Criminal acts dangerous to the public" and "Criminal acts against the environment". In Switzerland, endangerment by nuclear energy, radioactive substances or ionizing radiation is punishable under Art. 326 of the Swiss Criminal Code and disregard of safety regulations under Chapter 9 of the Nuclear Energy Act of 21 March 2003.
==== The tandem principle ==== The solution emerged from a charge-reversal concept proposed demonstrated by Nobel laureate Luis Alvarez in 1951. Rather than accelerate positive ions from ground to a high-voltage terminal, the tandem accelerator begins with negative ions. These particles accelerate toward a positive terminal, where a thin foil or gas stripper removes multiple electrons, converting them to positive ions. The now-positive particles accelerate away from the terminal back to ground potential. This double acceleration effectively multiplies the particle energy without requiring proportionally higher terminal voltages. A negative hydrogen ion accelerated through a 5 megavolt tandem emerges with 10 megavolts of kinetic energy. After commissioning tandem production in 1954, Atomic Energy of Canada Limited placed HVEC's first tandem order in September 1956 for $0.92M (equivalent to $10.89M in 2025). The machine achieved first beam at HVEC's Burlington facility in June 1958.
== Awards and honours == 2004 CWA Ian Fleming Steel Dagger Award shortlist for Dead I Well May Be 2007 Audie Award for Best Thriller/Suspense for The Dead Yard. 2008 Young Hoosier Award and Beehive Award shortlist for The Lighthouse Land 2009 World Book Day Award longlist for The Bloomsday Dead 2010 Spinetingler Award for Best Novel for Fifty Grand 2011 Theakston Old Peculier Crime Novel of the Year Award longlist for Fifty Grand 2013 Spinetingler Award for Best Crime Novel for The Cold Cold Ground 2013 Prix Du Meilleur Polar shortlist for The Cold Cold Ground 2013 Crime Fest Last Laugh Award shortlist for The Cold Cold Ground 2013 Ned Kelly Award for Best Crime Novel shortlist for I Hear the Sirens in the Street 2014 Barry Award (for crime novels)for Best Mystery Novel (Paperback Original) for I Hear the Sirens in the Street 2014 Grand Prix de Littérature Policière shortlist for I Hear the Sirens in the Street 2014 Theakston Old Peculier Crime Novel of the Year Award shortlist for I Hear the Sirens in the Street 2014 Ned Kelly Award for Best Fiction for In the Morning I'll Be Gone 2015 Audie Award For Best Thriller shortlist for In the Morning I'll Be Gone 2015 Prix SNCF Du Polar shortlist for The Cold Cold Ground 2015 Ned Kelly Award shortlist for Gun Street Girl 2015 Boston Globe Best Book of 2015 for Gun Street Girl 2015 Irish Times Best Crime Novel of 2015 for Gun Street Girl 2016 Edgar Award (Best Paperback Original) shortlist for Gun Street Girl 2016 Anthony Award (Best Paperback Original) shortlist for Gun Street Girl 2016 Audie Award for Best Mystery shortlist for Gun Street Girl 2016 Boston Globe Best Book of 2016 for Rain Dogs 2016 Irish Times Best Crime Novel of 2016 for Rain Dogs 2016 Theakston Old Peculier Crime Novel of the Year Award shortlist for Rain Dogs 2016 Ned Kelly Award shortlist for Rain Dogs 2016 CWA Ian Fleming Steel Dagger shortlist for Rain Dogs 2017 Edgar Award (Best Paperback Original) for Rain Dogs 2017 Barry Award for Rain Dogs 2017 Anthony Award (Best Paperback Original) for Rain Dogs 2017 Ned Kelly Award for Police at the Station and They Don't Look Friendly 2017 CWA Ian Fleming Steel Dagger Award shortlist for Police at the Station and They Don't Look Friendly 2017 Boston Globe Best Book of 2017 for Police at the Station and They Don't Look Friendly 2018 International Thriller Writers Awards (Best Paperback Original Novel) shortlist for Police at the Station and They Don't Look Friendly 2019 Time magazine Books of the Year for The Chain 2020 Theakston's Old Peculier Crime Novel of the Year Award 2020 winner for The Chain. 2020 Ian Fleming Steel Dagger Award longlist for The Chain; CWA Body in the Library longlist for The Chain 2020 International Thriller Writers Award for Best Hardcover Novel, The Chain. 2020 Ned Kelly Award for Best International Crime Fiction for The Chain. 2020 Macavity Awards for Best Mystery Novel by Mystery Readers International for The Chain. 2020 Barry Award (for crime novels) for Best Mystery Novel winner for The Chain. 2022 In The Morning I'll Be Gone winner of the Prix Polar Pourpres for Best Mystery Novel 2022 Best Thrillers of 2022 for The Island. New York Times 2023 Best Thrillers of 2023 for The Detective Up Late. Washington Post 2024 Barry Award (for crime novels) nominee for Best Mystery Novel for The Detective Up Late
Sources: en.wikipedia.org
The uncertainty in molecular mass reflects variance (error) in measurement not the natural variance in isotopic abundances across the globe. In high-resolution mass spectrometry the mass isotopomers 12C1H4 and 13C1H4 are observed as distinct molecules, with molecular masses of approximately 16.031 Da and 17.035 Da, respectively. The intensity of the mass-spectrometry peaks is proportional to the isotopic abundances in the molecular species. 12C 2H 1H3 can also be observed with molecular mass of 17 Da.
==== Mechanism of action ==== Xanomeline modulates certain dopaminergic and glutamatergic circuits in the brain that can provide therapeutic benefits in patients suffering from neuropsychiatric and neurological diseases such as schizophrenia and Alzheimer's disease through stimulation primarily of central M1 and M4 muscarinic receptor subtypes. Muscarinic M1 and M4 receptors have been shown in preclinical studies to be expressed in areas important for dopamine and glutamate neural circuit regulation (e.g. frontal cortex and dorsal and ventral striatum). Xanomeline has shown antipsychotic-like effects in various preclinical behavioral models, such as attenuation of amphetamine-induced locomotor hyperactivity, effects that are dependent on M1 and M4 receptor activation.
== Long-term regulation of hunger and food intake == The regulation of appetite (the appestat) has been the subject of much research; breakthroughs included the discovery, in 1994, of leptin, a hormone produced by the adipose tissue that appeared to provide negative feedback. Leptin is a peptide hormone that affects homeostasis and immune responses. Lowering food intake can lower leptin levels in the body, while increasing the intake of food can raise leptin levels. Later studies showed that appetite regulation is an immensely complex process involving the gastrointestinal tract, many hormones, and both the central and autonomic nervous systems. The circulating gut hormones that regulate many pathways in the body can either stimulate or suppress appetite. For example, ghrelin stimulates appetite, whereas cholecystokinin and glucagon-like peptide-1 (GLP-1) suppress appetite.
Sources: en.wikipedia.org
Creatine monohydrate is the hydrated solid form of creatine, a nitrogen-containing compound involved in cellular energy metabolism. It consists of one creatine molecule associated with one water molecule in a crystal lattice.
No. Creatinine is a breakdown product formed when creatine loses water and cyclizes, and it is not the same compound. The two names are similar but refer to different chemical structures and roles.
The body synthesizes creatine from amino acids, mainly in the liver and kidneys. It also comes from animal foods such as meat and fish, while plant foods contain little or none.
Yes, especially when exposed to moisture or heat, where it converts to creatinine. In dry, sealed containers at room temperature, degradation is slow and the product may remain within specification for two to three years.