Everything below concerns monohydrate. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-11-30. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Stability studies typically examine the effects of temperature, humidity, and light on creatine monohydrate. Sealed containers stored in cool, dry conditions help limit moisture uptake and hydrolysis. Elevated temperature and high relative humidity can accelerate conversion to creatinine, especially in aqueous solutions. In solid dosage forms, excipients and processing steps may also affect stability. Published stability data are not fully consistent across studies because test conditions and analytical methods vary.
| 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. |
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.
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.
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.
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.
Iron-sulfur protein NUBPL (IND1) also known as nucleotide-binding protein-like (NUBPL), IND1 homolog, Nucleotide-binding protein-like or huInd1 is an iron-sulfur (Fe/S) protein that, in humans, is encoded by the NUBPL gene, located on chromosome 14q12. It has an early role in the assembly of the mitochondrial complex I assembly pathway. NUBPL is located on the q arm of chromosome 14 in position 12 and has 18 exons. The NUBPL gene produces a 5.9 kDa protein composed of 54 amino acids. The structure of the protein includes a presumed iron-sulfur binding (CxxC) signature, a nucleotide-binding domain which has been highly conserved, and a mitochondrial targeting sequence in the N-terminal. NUBPL is required for the assembly of complex I, which is composed of 45 evolutionally conserved core subunits, including both mitochondrial DNA and nuclear encoded subunits. One of its arms is embedded in the inner membrane of the mitochondria, and the other is embedded in the organelle. The two arms are arranged in an L-shaped configuration. The total molecular weight of the complex is 1MDa.
The marine sulfur cycle is driven by sulfate reduction because hydrogen sulfide is oxidized by microbes for energy or is oxidized abiotically. Dissimilatory sulfate reduction is driven by the degradation of buried organic matter and anaerobic oxidation of methane (AOM) both of which produce carbon dioxide. At depths where sulfate is depleted, methanogenesis is prevalent. At the sulfate-methane transition zone (SMTZ), the upwelling of methane produced by the methanogens is met by the anaerobic methanotrophic archaea in the SMTZ which oxidize it using sulfate as an electron acceptor. More sulfate is present at the SMTZ than methane. A 4:1 ratio of sulfate: methane is observed and the excess sulfate is directed towards organic matter degradation. Syntrophic aggregates of sulfate reducers and methanotrophs have been discovered and the underlying mechanisms observed include direct interspecies electron transfer using large multi heme complexes.
γ-Aminobutyric acid (GABA) prodrugs include progabide and tolgabide. Picamilon (N-nicotinoyl-GABA) has been claimed to be a prodrug of GABA, but has not actually been demonstrated to be converted into GABA. N-Benzoyl-GABA is of very similar chemical structure as picamilon and has also been claimed to be a prodrug of GABA, but this remains unclear similarly. Pivagabine (N-pivaloyl-GABA) was once thought to be a prodrug of GABA, but this proved not to be the case. Cetyl-GABA (GABA cetyl ester) is another prodrug of GABA. 4-Amino-1-butanol is known to be converted into GABA through the actions of aldehyde reductase (ALR) and aldehyde dehydrogenase (ALDH). 4-Amino-1-butanol is to GABA as 1,4-butanediol (4-hydroxy-1-butanol; 1,4-BD) is to γ-hydroxybutyric acid (GHB) (with 1,4-BD being a well-known prodrug of GHB). The metabolic intermediate γ-aminobutyraldehyde (GABAL) is also converted into GABA. A number of γ-hydroxybutyric acid (GHB) prodrugs are known. These include 1,4-butanediol (1,4-BD) and γ-butyrolactone (GBL), as well as the metabolic intermediate γ-hydroxybutyraldehyde (GHBAL).
ADP glucose pyrophosphorylase (AGPase) soluble starch synthase (SS) starch branching enzyme (BE) starch debranching enzyme (DBE) Amylopectin is synthesized by the linkage of α(1→4) glycosidic bonds. The extensive branching of amylopectin (α(1→6) glycosidic bond) is initiated by BE and this is what differentiates amylose from amylopectin. DBE is also needed during this synthesis process to regulate the distribution of these branches. The breakdown of amylopectin has been studied in context with the breakdown of starch in animals and humans. Starch is mostly composed of amylopectin and amylose, but amylopectin has been shown to degrade more easily. The reason is most likely because amylopectin is highly branched and these branches are more available to digestive enzymes. In contrast, amylose tends to form helices and contain hydrogen bonding. The breakdown of starch is dependent on three enzymes, among others:
Sources: en.wikipedia.org
The European Aviation Safety Agency (EASA) is tasked by Article 15(4) of Regulation (EC) No 216/2008 of the European Parliament and of the Council of February 20, 2008, to provide an annual review of aviation safety. The Annual Safety Review presents statistics on European and worldwide civil aviation safety. Statistics are grouped according to type of operation, for instance, commercial air transport, and aircraft category, such as aeroplanes, helicopters, gliders, etc. The Agency has access to accident and statistical information collected by the International Civil Aviation Organization (ICAO). States are required, according to ICAO Annex 13, on Aircraft Accident and Incident Investigation, to report to ICAO information, on accidents and serious incidents to aircraft with a maximum certificated take-off mass (MTOM) over 2250 kg. Therefore, most statistics in this review concern aircraft above this mass. In addition to the ICAO data, a request was made to the EASA Member States to obtain light aircraft accident data. Furthermore, data on the operation of aircraft for commercial air transport were obtained from both ICAO and the NLR Air Transport Safety Institute.
There are over 100 reported pathogenic, or disease-causing, variants in the ASH1L gene. About half of the variants arise de novo, and half are inherited. Of the inherited variants, about half are maternally inherited and half are paternally inherited. Disease-causing variants may be missense, nonsense, or frameshift mutations. The missense mutations are distributed throughout the gene body without localizing to a known functional domain of ASH1L. All affected humans are heterozygous for ASH1L mutations. A single pathogenic copy of ASH1L causes disease, which may be the result of two different genetic mechanisms: haploinsufficiency or dominant negative function. The ClinGen clinical genomics resource states that there is "Sufficient Evidence for Haploinsufficiency" in ASH1L. The most common phenotypes, or symptoms, related to ASH1L mutations are autism spectrum disorder (ASD), epilepsy, intellectual disability, and attention deficit hyperactivity disorder (ADHD). The Simons Foundation Autism Research Initiative (SFARI) gives ASH1L a score of 1.1, indicating that ASH1L is a high confidence autism gene with the best level of evidence linking it to autism.
Cell shrinkage and rounding occur because of the two parallel processes: (a) retraction of lamellipodia and the breakdown of the proteinaceous cytoskeleton by caspases and (b) water removal decreasing cytoplasmic diffusion. The cytoplasm appears dense, and the organelles appear tightly packed. Chromatin undergoes condensation into compact patches against the nuclear envelope (also known as the perinuclear envelope) in a process known as pyknosis, a hallmark of apoptosis. The nuclear envelope becomes discontinuous and the DNA inside it is fragmented in a process referred to as karyorrhexis. The nucleus breaks into several discrete chromatin bodies or nucleosomal units due to the degradation of DNA. Apoptosis progresses quickly and its products are quickly removed, making it difficult to detect or visualize on classical histology sections. During karyorrhexis, endonuclease activation leaves short DNA fragments, regularly spaced in size. These give a characteristic "laddered" appearance on agar gel after electrophoresis. Tests for DNA laddering differentiate apoptosis from ischemic or toxic cell death.
Synthesis of RNA typically occurs in the cell nucleus and is usually catalyzed by an enzyme—RNA polymerase—using DNA as a template, a process known as transcription. Initiation of transcription begins with the binding of the enzyme to a promoter sequence in the DNA (usually found "upstream" of a gene). The DNA double helix is unwound by the helicase activity of the enzyme. The enzyme then progresses along the template strand in the 3' to 5' direction, synthesizing a complementary RNA molecule with elongation occurring in the 5' to 3' direction. The DNA sequence also dictates where termination of RNA synthesis will occur. Primary transcript RNAs are often modified by enzymes after transcription. For example, a poly(A) tail and a 5' cap are added to eukaryotic pre-mRNA and introns are removed by the spliceosome. There are also a number of RNA-dependent RNA polymerases that use RNA as their template for synthesis of a new strand of RNA. For instance, a number of RNA viruses (such as poliovirus) use this type of enzyme to replicate their genetic material. Also, RNA-dependent RNA polymerase is part of the RNA interference pathway in many organisms.
Approximately 0.2 to 1% of people have a "weak D" phenotype, meaning that they are positive for the RhD antigen, but exhibit weak or negative reactions with some anti-RhD reagents due to decreased antigen expression or atypical variants of antigen structure. If routine serologic testing for RhD results in a score of 2+ or less, the antiglobulin test can be used to demonstrate the presence of RhD. Weak D testing is also performed on blood donors who initially type as RhD negative. Historically, blood donors with weak D were treated as Rh positive and patients with weak D were treated as Rh negative in order to avoid potential exposure to incompatible blood. Genotyping is increasingly used to determine the molecular basis of weak D phenotypes, as this determines whether or not individuals with weak D can produce antibodies against RhD or sensitize others to the RhD antigen.
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.
Purity is commonly assessed by HPLC, which separates creatine from related compounds such as creatinine. Water content is measured separately by Karl Fischer titration. Together these results help calculate the actual creatine content in a sample.