If you have been reading about Creatine monohydrate 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 2025-12-24. 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.
Solid creatine monohydrate is generally stable when kept cool and dry, but it can hydrolyze to creatinine over time. Moisture, heat, and acidic conditions accelerate this conversion, which reduces assay values and changes the material's properties. Creatinine is a cyclic dehydration product that is also a normal human metabolite, so its presence in a sample is not necessarily a health concern by itself. In quality testing, creatinine is monitored as a marker of degradation and purity.
Identity and purity are assessed with several complementary methods. High-performance liquid chromatography can separate creatine from creatinine and related impurities, often with ultraviolet detection. Nuclear magnetic resonance and infrared spectroscopy provide structural confirmation, while Karl Fischer titration measures water content. Elemental analysis and mass spectrometry may be used for additional confirmation, especially in research or forensic settings. No single method captures every quality attribute, so laboratories typically combine results and compare them against a specification.
| 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.
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.
== K == kainic acid receptor - kallidin - kappa opioid receptor - kappa-chain immunoglobulin - karyoplasm - karyotype - kelvin - keratin - kinase - kinesin - kinetic energy - kinetic exclusion assay - kinetics - knock-out mouse - Krebs cycle
=== Lethal dose === Death from caffeine ingestion appears to be rare, and most commonly caused by an intentional overdose of medications. In 2016, 3702 caffeine-related exposures were reported to Poison Control Centers in the United States, of which 846 required treatment at a medical facility, and 16 had a major outcome; and several caffeine-related deaths are reported in case studies. The LD50 of caffeine in rats is 192 milligrams per kilogram of body mass. The fatal dose in humans is estimated to be 150–200 milligrams per kilogram, which is 10.5–14 grams for a typical 70 kg (150 lb) adult, equivalent to about 75–100 cups of coffee. There are cases where doses as low as 57 milligrams per kilogram have been fatal. A number of fatalities have been caused by overdoses of readily available powdered caffeine supplements, for which the estimated lethal amount is less than a tablespoon. The lethal dose is lower in individuals whose ability to metabolize caffeine is impaired due to genetics or chronic liver disease. A death was reported in 2013 of a man with liver cirrhosis who overdosed on caffeinated mints.
The concerns about the adverse effects of non-noble varieties, produced by their undesirable composition of kavalactones and high concentrations of potentially harmful compounds (flavokavains, which are not present in any significant concentration in the noble varieties), have led to legislation prohibiting exports from countries such as Vanuatu. Likewise, efforts have been made to educate non-traditional customers about the difference between noble and non-noble varieties and that non-noble varieties do not offer the same results as noble cultivars. In recent years, government regulatory bodies and non-profit NGOs have been set up with the declared aim of monitoring kava quality; producing regular reports; certifying vendors selling proper, noble kava; and warning customers against products that may contain tudei varieties.
Sources: en.wikipedia.org
=== Contraindications === Although cruciferous vegetables are generally safe for human consumption, individuals with known allergies or hypersensitivities to a certain Brassica vegetable, or those taking anticoagulant therapy, should be cautious.
== Work == In 1934 Flory joined the Central Department of Dupont and Company working with Wallace H. Carothers. After Carothers' death in 1937, Flory worked for two years at the Basic Research Laboratory located in the University of Cincinnati. During World War II, there was a need for research to develop synthetic rubber, so Flory joined the Esso Laboratories of the Standard Oil Development Company. From 1943 to 1948 Flory worked in the polymer research team of the Goodyear Tire and Rubber Company. In 1948, Flory gave the George Fisher Baker lectures at Cornell University, and subsequently joined the university as a professor. In 1957, Flory and his family moved to Pittsburgh, Pennsylvania, where Flory was executive director of research at the Mellon Institute of Industrial Research. In 1961, he took up a professorship at Stanford University in the department of chemistry. After retirement, Flory remained active in the world of chemistry, running research labs both in Stanford, and IBM.
Upon taking office in 2001, Bush stated his opposition to the Kyoto Protocol, an amendment to the United Nations Framework Convention on Climate Change which seeks to impose mandatory targets for reducing greenhouse gas emissions, citing that the treaty exempted 80% of the world's population and would have cost tens of billions of dollars per year. He also cited that the Senate had voted 95–0 in 1997 on a resolution expressing its disapproval of the protocol. In May 2001, Bush signed an executive order to create an interagency task force to streamline energy projects, and later signed two other executive orders to tackle environmental issues. In 2002, Bush proposed the Clear Skies Act of 2003, which aimed at amending the Clean Air Act to reduce air pollution through the use of emissions trading programs. Many experts argued that this legislation would have weakened the original legislation by allowing higher emission rates of pollutants than were previously legal. The initiative was introduced to Congress, but failed to make it out of committee. Later in 2006, Bush declared the Northwestern Hawaiian Islands a national monument, creating the largest marine reserve to date. The Papahānaumokuākea Marine National Monument comprises 84 million acres (340,000 km2) and is home to 7,000 species of fish, birds, and other marine animals, many of which are specific to only those islands. The move was hailed by conservationists for "its foresight and leadership in protecting this incredible area".
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 kept at room temperature and away from moisture is typical. Heat and humidity promote conversion to creatinine and can reduce assay values. Long-term storage under dry conditions helps maintain the original crystalline form.