Creatine monohydrate 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.
Updated 2026-07-11. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 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.
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.
| 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. |
Dry creatine monohydrate is generally stable when kept sealed and protected from heat and moisture. In solution, however, creatine undergoes a slow cyclization to creatinine, a related compound with no role in phosphocreatine storage. The rate of this conversion increases with temperature and is influenced by pH. Because creatinine is a common impurity in liquid or poorly stored products, analytical testing often measures both compounds. The crystalline monohydrate is less prone to degradation than aqueous preparations, though caking can occur if moisture enters the container.
Laboratory analysis of creatine monohydrate typically uses high-performance liquid chromatography to separate creatine from creatinine and other impurities. Detection may be ultraviolet, refractive index, or mass spectrometric, depending on the laboratory's equipment and the required sensitivity. Nuclear magnetic resonance spectroscopy can quantify the main component and identify related substances. Water content is measured by Karl Fischer titration, which is important because the monohydrate has a defined theoretical hydration level. Heavy metals, residual solvents, and microbial limits are also checked in quality control programs.
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.
== Career == Chen began her career at the Institute of Chemistry of Academia Sinica as assistant research fellow in 1999. She was the Director of the Institute of Chemistry from 2013 to 2019, and is currently a Distinguished Research Fellow. She is also an adjunct professor at National Taiwan University, National Chiayi University, National Taiwan Ocean University, and National Chung Hsing University. She conducts research in mass spectrometry-based bioinformatics, in relation to understanding diseases such as cancer. Since 2016, Chen has participated in the US Cancer Moonshot Initiative, providing proteogenomics expertise as representative of Academia Sinica. She is the project investigator for the Taiwan Cancer Moonshot Project, which analyzes multiomic data related to gastric cancer. She participates in the Chromosome-centric Human Proteome Project, and is the group lead of chromosome 4. Chen served as president for the Human Proteome Organization (2021-2022), the Taiwan Proteomics Society, and the Taiwan Society for Mass Spectrometry (2012-2015). She has been a council member of the Asia Oceania Human Proteome Organization since 2019. She current serves as executive director of the Taiwan Proteomics Society (2021-2023), and the Taiwan Society for Mass Spectrometry. She served on editorial boards of European Journal of Mass Spectrometry, Journal of Proteome Research, and Frontiers in Analytical Chemistry, and currently serves on the Executive Advisory Board of Proteomics.
An immigration judge rules that Trump can deport the Palestinian-born leader of Wisconsin's largest mosque—an outspoken advocate of Palestinian rights—who does not have a criminal record in the US, where he has lived since 1993 on national security grounds, citing his imprisonment in Israel in 1988 after being convicted of throwing stones at Israeli military personnel in the West Bank.
A property of DNA is its ability to re-anneal into double-stranded molecules when pH conditions are neutralized. Under neutral conditions, hydrogen bonds reform between complementary base pairs. Because the plasmid was so tightly coiled and small before the alkaline conditions were established, it can easily re-anneal. The chromosomal DNA, however, because of its lengthy strands, does not re-anneal. Once the plasmid DNA reassociates into double-stranded molecules, it dissolves into the solution. Potassium acetate reacts with the SDS detergent, magnesium ions, and calcium ions already present in the solution and forms potassium dodecyl sulfate (KDS), an insoluble white solid which precipitates out of solution. The remaining chromosomal DNA strands, denatured proteins, and added chemicals stick together and precipitate out with the KDS. The plasmid DNA, however, remains dissolved in the liquid solution. The solution is usually centrifuged to collect the insoluble precipitates into a debris pellet at the bottom of the sample tube and thereby isolate them from the supernatant.
Sources: en.wikipedia.org
According to one cable, Deputy Assistant Secretary of State for European and Eurasian Affairs Matthew Bryza "has been clear with Saakashvili: if Georgia uses force or stumbles into a conflict, Saakashvili will find himself alone, blamed by the international community for recklessness." Tefft was told by an Abkhaz official in 2007 that there had been an attempt by Russia to coerce Abkhaz leader Sergei Bagapsh into launching a military operation against Georgia in 2006. President of France Nicolas Sarkozy assured Putin in October 2007 that France did not support Georgia's NATO membership while telling Saakashvili the opposite. In January 2008, the French government was not enthusiastic about Ukraine's plans to join NATO.
== Further reading == Ye, Yanqi; Yu, Jicheng; Gu, Zhen (2015). "Versatile Protein Nanogels Prepared by In Situ Polymerization". Macromolecular Chemistry and Physics. 217 (3): 333–343. doi:10.1002/macp.201500296. Yan, Ming; Ge, Jun; Liu, Zheng; Ouyang, Pingkai (2006). "Encapsulation of Single Enzyme in Nanogel with Enhanced Biocatalytic Activity and Stability". Journal of the American Chemical Society. 128 (34): 11008–9. Bibcode:2006JAChS.12811008Y. doi:10.1021/ja064126t. PMID 16925402. Reese, Chad E.; Mikhonin, Alexander V.; Kamenjicki, Marta; Tikhonov, Alexander; Asher, Sanford A. (2004). "Nanogel Nanosecond Photonic Crystal Optical Switching". Journal of the American Chemical Society. 126 (5): 1493–6. Bibcode:2004JAChS.126.1493R. doi:10.1021/ja037118a. PMID 14759207. Lee, Eun Seong; Kim, Dongin; Youn, Yu Seok; Oh, Kyung Taek; Bae, You Han (2008). "A Virus-Mimetic Nanogel Vehicle". Angewandte Chemie International Edition. 47 (13): 2418–21. Bibcode:2008ACIE...47.2418L. doi:10.1002/anie.200704121. PMC 3118583. PMID 18236507. Hasegawa, Urara; Nomura, Shin-Ichiro M.; Kaul, Sunil C.; Hirano, Takashi; Akiyoshi, Kazunari (2005). "Nanogel-quantum dot hybrid nanoparticles for live cell imaging". Biochemical and Biophysical Research Communications. 331 (4): 917–21. Bibcode:2005BBRC..331..917H. doi:10.1016/j.bbrc.2005.03.228. PMID 15882965. Du, Jin-Zhi; Sun, Tian-Meng; Song, Wen-Jing; Wu, Juan; Wang, Jun (2010). "A Tumor-Acidity-Activated Charge-Conversional Nanogel as an Intelligent Vehicle for Promoted Tumoral-Cell Uptake and Drug Delivery".
== New roles == Recent findings suggest that StAR may also traffic cholesterol to a second mitochondrial enzyme, sterol 27-hydroxylase. This enzyme converts cholesterol to 27-hydroxycholesterol. In this way it may be important for the first step in one of the two pathways for the production of bile acids by the liver (the alternative pathway). Evidence also shows that the presence of StAR in a type of immune cell, the macrophage, where it can stimulate the production of 27-hydroxycholesterol. In this case, 27-hydroxycholesterol may by itself be helpful against the production of inflammatory factors associated with cardiovascular disease. No study has yet found a link between the loss of StAR and problems in bile acid production or increased risk for cardiovascular disease. Recently StAR was found to be expressed in cardiac fibroblasts in response to ischemic injury due to myocardial infarction. In these cells it has no apparent de novo steroidogenic activity, as evidenced by the lack of the key steroidogenic enzymes cytochrome P450 side chain cleavage (CYP11A1) and 3 beta hydroxysteroid dehydrogenase (3βHSD). StAR was found to have an anti-apoptotic effect on the fibroblasts, which may allow them to survive the initial stress of the infarct, differentiate and function in tissue repair at the infarction site.
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.
A sealed container at room temperature, away from moisture and direct heat, is suitable for most solid material. Keeping the lid closed limits water uptake and caking. Long-term storage in a refrigerator is not necessary if the powder remains dry.