Nitrogenous organic acid 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.
Last reviewed on 2026-04-12. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Creatine monohydrate is a crystalline compound formed from creatine and one water molecule in its solid lattice. Creatine itself is a nitrogen-containing organic acid involved in energy transfer in muscle and other tissues. The monohydrate form is the most common solid form used in research and commercial products because it is stable and easy to handle. The term "monohydrate" refers to the fixed one-to-one ratio of water to creatine in the crystal, not to moisture content. This distinction matters when comparing labels or calculating creatine content.
In chemical terms, creatine monohydrate is often described as N-(aminoiminomethyl)-N-methylglycine monohydrate, though nomenclature varies. Its solid state consists of zwitterionic creatine molecules linked with water through hydrogen bonding. The compound dissolves in water, but dissolution rate depends on particle size, temperature, and agitation. Once dissolved, the hydrate water becomes part of the solvent, leaving free creatine in solution. The monohydrate is not the same as creatine anhydrous, which lacks the water of crystallization and has a higher creatine fraction by mass.
Commercial creatine monohydrate is typically a white to off-white powder with low odor. It is commonly sold as a fine powder, micronized powder, or larger crystals, but these are physical forms of the same chemical. Purity grades vary, and products may contain small amounts of related substances such as creatinine, dicyandiamide, or moisture. The monohydrate is often selected for supplements and research because its production is well established and its behavior in water is predictable. Analytical certificates usually report assay, loss on drying, and heavy metals.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C4H11N3O3·H2O | Hydrated form includes one water molecule per creatine unit. |
| Molar mass | 149.15 g/mol | Calculated for the monohydrate form. |
| Appearance | White crystalline powder | Common commercial grade is odorless or nearly odorless. |
| Solubility in water | Moderately soluble | Solubility increases with temperature and depends on pH. |
| Common synonyms | Creatine hydrate; N-methylguanidinoacetic acid | Monohydrate distinguishes it from anhydrous creatine. |
Quality control for creatine monohydrate begins with identity confirmation and assay determination. Laboratories commonly use high-performance liquid chromatography with ultraviolet detection, often after derivatization or using a suitable column, to quantify creatine. Karl Fischer titration measures water content, which helps verify the monohydrate stoichiometry. Additional tests screen for heavy metals, residual solvents, and microbial contamination depending on the intended use. These tests establish composition and purity rather than biological effect.
Stability studies examine how creatine monohydrate changes under controlled temperature and humidity. The solid is generally stable when kept dry, but moisture can promote hydrolysis to creatinine, especially in solution or at elevated temperatures. Color, odor, and assay values are monitored over time to detect degradation. Because degradation pathways depend on storage conditions, shelf-life claims should specify the tested packaging, temperature, and humidity. Open questions remain about the long-term behavior of different crystal habits and particle sizes.
Regulatory treatment of creatine monohydrate varies by country and intended use. In some jurisdictions it is sold as a dietary supplement, while in others it may be treated as a food ingredient or a pharmaceutical raw material. Pharmacopeial monographs, where available, define identification, assay limits, and impurity thresholds. Manufacturers often follow these monographs or internal specifications to ensure batch-to-batch consistency. Analytical method validation is important because different methods can yield different apparent purity values if sample preparation or detection conditions are not controlled.
Solid creatine monohydrate is relatively stable when kept dry and sealed, but heat and moisture accelerate its conversion to creatinine. This degradation involves intramolecular cyclization, a process that removes water and forms a less useful compound for phosphocreatine metabolism. Powder stored under cool, dry conditions can remain within specification for extended periods, though exact shelf life depends on packaging, humidity, and initial purity. Aqueous solutions degrade faster than dry powder, with pH and temperature influencing the rate. Because degradation is gradual, analytical testing is used to confirm potency at manufacture and during stability studies.
Quality control for creatine monohydrate typically combines identity, assay, and impurity tests. High-performance liquid chromatography with ultraviolet detection is common for separating creatine from creatinine and related substances. Nuclear magnetic resonance and infrared spectroscopy can confirm molecular structure, while titration may assess acid-base content. Moisture content, heavy metals, residual solvents, and microbial limits are checked according to applicable standards. These tests help distinguish compliant material from powders that have degraded, been diluted, or contain manufacturing residues.
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.
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.
This supports the significant role of these two residues in the selectivity for C-domain. These two analogues also have less potency for the C-domain which shows that the C-domain prefers pseudo-phenylalanine group in P1 position. Modeling of RXPA380-ACE complex showed that the pseudo-proline residue of the inhibitor was surrounded by amino acids similar to that of the N-domain thus interactions with S2’ domain might not be responsible for the selectivity of RXPA380. Seven of 12 amino acids surrounding tryptophan are the same in C- and N-domain, the biggest difference is that 2 bulky and hydrophobic amino acids in the C-domain have been replaced with 2 smaller and polar amino acids in the N-domain. This indicates that low potency of RXPA380 for N-domain is not because the S2’ cavity does not accommodate the tryptophan side chain but rather that important interactions are missing between the tryptophan side chain and the amino acids of the C-domain. Based on the proximity between the tryptophan side chain and Asp1029 there is also a possible hydrogen bond between the carboxylate of Asp1029 and the NH indole ring in the C-domain but this interaction is much weaker in the N-domain.
Bush's legacy continues to develop, as time allows the development of a more nuanced historical perspective. Supporters credit his counterterrorism policies with preventing another major terrorist attack in the U.S. after September 11 and praise policies such as the Medicare prescription drug benefit and the AIDS relief program known as PEPFAR. Critics point to his handling of the Iraq War, specifically the failure to find weapons of mass destruction after claiming they were in Iraq, as well as Bush's handling of tax policy, Hurricane Katrina, climate change and the 2008 financial crisis, as proof he was unfit to be president. Ben Ferencz, chief prosecutor for the US Army at the Nuremberg Trials, stated that Bush likely committed war crimes in relation to the Iraq War. Several historians and commentators hold that Bush was one of the most consequential presidents in American history. Julian Zelizer described Bush's presidency as a "transformative" one, and said that "some people hate him, some people love him, but I do think he'll have a much more substantive perception as time goes on". Bryon Williams of The Huffington Post referred to Bush as "the most noteworthy president since FDR" and said the Patriot Act "increased authority of the executive branch at the expense of judicial opinions about when searches and seizures are reasonable" as evidence. Bush's administration presided over the largest tax cuts since the presidency of Ronald Reagan, and his homeland security reforms proved to be the most significant expansion of the federal government since the Great Society.
=== The beginning: crystal structure of tRNAPHE === In the mid-1960s, the role of tRNA in protein synthesis was being intensively studied. At this point, ribosomes had been implicated in protein synthesis, and it had been shown that an mRNA strand was necessary for the formation of these structures. In a 1964 publication, Warner and Rich showed that ribosomes active in protein synthesis contained tRNA molecules bound at the A and P sites, and discussed the notion that these molecules aided in the peptidyl transferase reaction. However, despite considerable biochemical characterization, the structural basis of tRNA function remained a mystery. In 1965, Holley et al. purified and sequenced the first tRNA molecule, initially proposing that it adopted a cloverleaf structure, based largely on the ability of certain regions of the molecule to form stem loop structures. The isolation of tRNA proved to be the first major windfall in RNA structural biology. Following Robert W. Holley's publication, numerous investigators began work on isolation tRNA for crystallographic study, developing improved methods for isolating the molecule as they worked. By 1968 several groups had produced tRNA crystals, but these proved to be of limited quality and did not yield data at the resolutions necessary to determine structure. In 1971, Kim et al. achieved another breakthrough, producing crystals of yeast tRNAPHE that diffracted to 2–3 Ångström resolutions by using spermine, a naturally occurring polyamine, which bound to and stabilized the tRNA.
Sources: en.wikipedia.org
Ophthalmic acid (OPH), also known as ophthalmate (chemically L-γ-glutamyl-L-α-aminobutyrylglycine), is a tripeptide analog of glutathione. However, instead of the cysteine essential for many of glutathione's diverse functions, it contains L-2-aminobutyrate, a non-proteinogenic amino acid lacking the nucleophilic thiol group. Because of this, it has been widely, and incorrectly, considered an accidental byproduct of glutathione synthesis. In 2024, an article published by the federation of European biochemistry societies compiled evidence to put forward the major hypothesis that OPH serves as a glutathione regulating tripeptide, affecting both cellular and organelle influx and efflux of GSH, as well as modulating GSH-dependent reactions and signaling.
With an established target exposure for optimized treatment effectiveness with minimized toxicities, dosing can be personalized to achieve target exposure and optimal results for each person. Such an algorithm was used in the clinical trials cited above and resulted in significantly improved treatment outcomes. Oncologists are already individualizing dosing of some cancer drugs based on exposure. Carboplatin and busulfan dosing rely upon results from blood tests to calculate the optimal dose for each person. Simple blood tests are also available for dose optimization of methotrexate, 5-FU, paclitaxel, and docetaxel. The serum albumin level immediately prior to chemotherapy administration is an independent prognostic predictor of survival in various cancer types.
(2017) in a Kozak-like region in the SOX9 gene that created a new translation initiation codon in an out-of-frame open reading frame. The correct initiation codon was located in a region that did not match the Kozak consensus sequence as closely as the surrounding sequence of the new, upstream initiation site did, which resulted in reduced translation efficiency of functional SOX9 protein. The patient in whom this mutation was detected had developed acampomelic campomelic dysplasia, a developmental disorder that causes skeletal, reproductive and airway issues due to insufficient SOX9 expression.
Sources: en.wikipedia.org
Atticus Shaffer (born June 19, 1998) is an American actor and YouTuber. He is known for playing Brick Heck on the ABC sitcom The Middle (2009–2018), as well for voicing Edgar in the movie Frankenweenie (2012) and Ono on the Disney Junior series The Lion Guard (2016–2019), and for his brief appearance in Hancock (2008). Shaffer also voices Morrie Rydell on Focus on the Family's Adventures in Odyssey.
Space Invaders, originally released for arcades in 1978, became a killer app when it was ported to the Atari VCS console in 1980, quadrupling sales of the three-year-old console. Star Raiders, released in 1980, was the first killer app computer game. BYTE named it the single most important reason for sales of Atari 400 and 800 computers. Another was Eastern Front (1941), released in 1981. In 1996, Computer Gaming World wrote that Wizardry: Proving Grounds of the Mad Overlord (1981) "sent AD&D fans scrambling to buy Apple IIs". The Famicom home port of Xevious is considered the console's first killer app, which caused system sales to jump by nearly 2 million units. Computer Gaming World stated that The Legend of Zelda on the Nintendo Entertainment System, Phantasy Star II on the Sega Genesis, and Far East of Eden for the NEC TurboGrafx-16 were killer apps for their consoles. The Super Mario, Final Fantasy, and Dragon Quest series were killer apps for Nintendo's Famicom and Super Famicom consoles in Japan. John Madden Football's popularity in 1990 helped the Genesis gain market share against the Super NES in North America. Sonic the Hedgehog, released in 1991, was hailed as a killer app as it revived sales of the three-year-old Genesis. Mortal Kombat helped pushed the sales of the Genesis due to being uncensored unlike the Nintendo version. Streets of Rage became a system seller for the Mega Drive/Genesis in the UK. Street Fighter II, originally released for arcades in 1991, became a system-seller for the Super NES when it was ported to the platform in 1992.
does not give credibility to the report and asserting that the Iranian regime is the only party committing war crimes in the conflict. The U.S. Central Command (CENTCOM) previously denied responsibility for the strike in Lamerd and stated it was investigating the incident in Minab.
Sources: en.wikipedia.org
In common usage, yes, but technically creatine monohydrate is one specific hydrated salt form. Other creatine forms exist and differ in composition and properties. The monohydrate is the most studied and most widely available grade.
Yes. Each creatine molecule in the crystal is associated with one water molecule. That water contributes to the total mass but is not part of the creatine molecule itself. Heating or drying can remove some or all of this water.
It occurs naturally in meat and fish, and the human body also makes and stores creatine. Food sources provide varying amounts depending on the type and preparation. The compound is not considered an essential dietary nutrient for adults because the body can synthesize it.
It is a solid form of creatine that contains one water molecule per creatine molecule in the crystal lattice. The hydrate water is part of the crystal structure rather than loose moisture. The term is often used for the common crystalline powder grade.