Nitrogenous organic acid is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-03-21. Where a claim depends on a specific study, the study is described rather than over-claimed.
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 animals, creatine is synthesized mainly in liver, kidney, and pancreas from arginine, glycine, and methionine. The first committed step transfers a guanidino group from arginine to glycine, forming guanidinoacetate. Subsequent methylation by S-adenosylmethionine yields creatine. Dietary sources include meat and fish; endogenous synthesis supplies part of the body pool. Most creatine is stored in skeletal muscle, where it is converted to phosphocreatine and participates in rapid regeneration of adenosine triphosphate during short, intense activity.
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.
| 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.
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.
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.
In the body, creatine is synthesized from the amino acids arginine, glycine, and methionine, primarily in the liver and kidneys. It is transported to muscle and other tissues, where it is phosphorylated to phosphocreatine by creatine kinase. This phosphagen system provides a rapid source of adenosine triphosphate during short, intense contractions. Dietary creatine comes mainly from meat and fish, and the body's total pool is influenced by both synthesis and intake.
As a supplement, creatine monohydrate is studied for its effects on muscle performance and recovery. The compound is often described as an ergogenic aid, meaning it may support physical work capacity. Research typically compares it with placebo or other forms, such as citrate or nitrate, under controlled conditions. Questions remain about the optimal dose and long-term effects in different populations, and findings are not uniform across all studies. The monohydrate form remains the most extensively tested.
This form of asexual reproduction, called parthenogenesis, occurs in several species of gecko, and is particularly widespread in the teiids (especially Aspidocelis) and lacertids (Lacerta). In captivity, Komodo dragons (Varanidae) have reproduced by parthenogenesis. Parthenogenetic species are suspected to occur among chameleons, agamids, xantusiids, and typhlopids. Some reptiles exhibit temperature-dependent sex determination (TDSD), in which the incubation temperature determines whether a particular egg hatches as male or female. TDSD is most common in turtles and crocodiles, but also occurs in lizards and tuatara. To date, there has been no confirmation of whether TDSD occurs in snakes.
The Dairy Division had been established in the Bureau of Animal Industry on July 1, 1895, and authorized by the Congress 'to collect and disseminate information relating to the dairy industry of the United States.' That was precisely and exclusively what it did until 1902, when L. A. Rogers became an employee of the Division. Rogers arrived in Washington followed by a flurry of activity. He attended his first meeting of the Society of American Bacteriologists, and with C. E. Gray was assigned an applied research project on butter, at Ames, Iowa, as animal industry staff were expected to make use of state experiment stations. When no adequate supply of milk for the research was available at Ames, the men "begged the use" of university facilities at Madison, Wisconsin. Following work in Wisconsin and Minnesota, Rogers and Gray
=== Embedding === Tissues are embedded in a harder medium both as a support and to allow the cutting of thin tissue slices. In general, water must first be removed from tissues (dehydration) and replaced with a medium that either solidifies directly, or with an intermediary fluid (clearing) that is miscible with the embedding media.
== Bibliography == Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth–Heinemann. ISBN 978-0080379418. Haire, Richard G. (2006). "Einsteinium". In Morss, Lester R.; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (PDF). Vol. 3 (3rd ed.). Dordrecht, the Netherlands: Springer. pp. 1577–1620. doi:10.1007/1-4020-3598-5_12. ISBN 978-1-4020-3555-5. Archived from the original (PDF) on 2010-07-17. Holleman, Arnold F. & Wiberg, Nils (2007). Textbook of Inorganic Chemistry (102nd ed.). Berlin: de Gruyter. ISBN 978-3-11-017770-1. Seaborg, G.T., ed. (23 January 1978). Proceedings of the Symposium Commemorating the 25th Anniversary of Elements 99 and 100 (PDF). Report LBL-7701.
Sources: en.wikipedia.org
=== Technology testing === All medical equipment introduced commercially must meet both United States and international regulations. The devices are tested on their material, effects on the human body, all components including devices that have other devices included with them, and the mechanical aspects. The Medical Device User Fee and Modernization Act of 2002 was created to speed up the FDA's approval process of medical technology by introducing sponsor user fees for a faster review time with predetermined performance targets for review time. In addition, 36 devices and apps were approved by the FDA in 2016.
== Solid-phase peptide synthesis (SPPS) == Solid-phase synthesis is a common technique for peptide synthesis. Usually, peptides are synthesised from the carbonyl group side (C-terminus) to amino group side (N-terminus) of the amino acid chain in the SPPS method, although peptides are biologically synthesised in the opposite direction in cells. In peptide synthesis, an amino-protected amino acid is bound to a solid phase material or resin (most commonly, low cross-linked polystyrene beads), forming a covalent bond between the carbonyl group and the resin, most often an amido or an ester bond. Then the amino group is deprotected and reacted with the carbonyl group of the next N-protected amino acid. The solid phase now bears a dipeptide. This cycle is repeated to form the desired peptide chain. After all reactions are complete, the synthesised peptide is cleaved from the bead. The protecting groups for the amino groups mostly used in the peptide synthesis are 9-fluorenylmethyloxycarbonyl group (Fmoc) and t-butyloxycarbonyl (Boc). A number of amino acids bear functional groups in the side chain which must be protected specifically from reacting with the incoming N-protected amino acids. In contrast to Boc and Fmoc groups, these have to be stable over the course of peptide synthesis although they are also removed during the final deprotection of peptides.
A study by Hutchinson and colleagues in 2011 corroborated the previous estimation methods in general, but their estimation of peak growth rates is significantly higher; it found that the "maximum growth rates for T. rex during the exponential stage are 1790 kg/year". Although these results were much higher than previous estimations, the authors noted that these results significantly lowered the great difference between its actual growth rate and the one which would be expected of an animal of its size. The sudden change in growth rate at the end of the growth spurt may indicate physical maturity, a hypothesis which is supported by the discovery of medullary tissue in the femur of a 16 to 20-year-old T. rex from Montana (MOR 1125, also known as B-rex). Medullary tissue is found only in female birds during ovulation, indicating that B-rex was of reproductive age. Further study indicates an age of 18 for this specimen. In 2016, it was finally confirmed by Mary Higby Schweitzer and Lindsay Zanno and colleagues that the soft tissue within the femur of MOR 1125 was medullary tissue. This also confirmed the identity of the specimen as a female. The discovery of medullary bone tissue within Tyrannosaurus may prove valuable in determining the sex of other dinosaur species in future examinations, as the chemical makeup of medullary tissue is unmistakable. Other tyrannosaurids exhibit extremely similar growth curves, although with lower growth rates corresponding to their lower adult sizes.
"Osteogenesis Imperfecta Overview". NIH Osteoporosis and Related Bone Diseases. National Resource Center, National Institutes of Health, U.S. Department of Health and Human Services. 8 May 2023. Archived from the original on 4 October 2017.
Additionally, certain ancient writers also believed poppy to be an important spice. Both Cato and Plauto wrote about its use as a spice, with archaeological evidence from seed cakes being found in ancient Roman farmhouses supporting these claims. The Greek gods Hypnos (Sleep), Nyx (Night), and Thanatos (Death) were depicted wreathed in poppies or holding them. Poppies also frequently adorned statues of Apollo, Asclepius, Pluto, Demeter, Aphrodite, Kybele and Isis, symbolizing nocturnal oblivion.
Sources: en.wikipedia.org
== Mechanism == As a derivative of EDTA, dexrazoxane chelates iron and thus reduces the number of metal ions complexed with anthracycline and, consequently, decrease the formation of superoxide radicals. The exact chelation mechanism is unknown, but it has been postulated that dexrazoxane can be converted into ring-opened form intracellularly and interfere with iron-mediated free radical generation that is in part thought to be responsible for anthracycline induced cardiomyopathy. It was speculated that dexrazoxane could be used for further investigation to synthesize new antimalarial drugs.
=== Serotonylation === Protein serotonylation refers to the post-translational modification in which serotonin is covalently attached to glutamine residues on substrate proteins via a transamidation reaction catalyzed by TGM2. Serotonylation is a type of monoaminylation, which itself refers to the overall class of post-translational modifications involving monoamines. However, monoaminylation reactions are further classified by the individual monoamine reactant they describe (ie., serotonylation, dopaminylation, histaminylation). Serotonylation has been reported for both histone and non-histone protein substrates, and thus represents a distinct neuroepigenetic and neuroproteomic regulatory mechanism with various implications in health and disease. Since 2003, multiple studies have revealed the critical role of serotonylation in mediating a wide range of physiological processes, both in the nervous system and beyond. Serotonylation is known to contribute to several significant diseases, including neuropsychiatric disorders such as depression and schizophrenia, as well as a variety of cancers. To date, notable protein serotonylation substrates include several metabolic enzymes (GAPDH, mTOR), Rab GTPases (Rab3a, Rab27a), Rho GTPases (RhoA, Rac1, Cdc42), proteins involved in muscle contractility (⍺-actinin, SERCA2a), extracellular matrix proteins (fibronectin), neural surface proteins, and Ras, as well as histone H3.
Cells are capable of synthesizing new proteins, which are essential for the modulation and maintenance of cellular activities. This process involves the formation of new protein molecules from amino acid building blocks based on information encoded in DNA/RNA. Protein synthesis generally consists of two major steps: transcription and translation. Transcription is the process where genetic information in DNA is used to produce a complementary RNA strand. This RNA strand is then processed to give messenger RNA (mRNA), which is free to migrate into the cytoplasm. mRNA molecules bind to protein-RNA complexes called ribosomes located in the cytosol, where they are translated into polypeptide sequences. The ribosome mediates the formation of a polypeptide sequence based on the mRNA sequence. The mRNA sequence directly relates to the polypeptide sequence by binding to transfer RNA (tRNA) adapter molecules in binding pockets within the ribosome. The new polypeptide chain then folds into a functional three-dimensional protein molecule.
== Adverse effects == Patiromer was generally well tolerated in studies. Side effects that occurred in more than 2% of patients included in clinical trials were mainly gastro-intestinal problems such as constipation, diarrhea, nausea, and flatulence, and also hypomagnesemia (low levels of magnesium in the blood) in 5% of patients, because patiromer binds magnesium in the gut as well.
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.
Creatine is the base compound, while creatine monohydrate includes one water molecule per creatine molecule in its crystal structure. The monohydrate form is common in supplements and analytical standards. The body uses creatine itself after the water is removed or dissociated.