Creatine monohydrate raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-05-04. Anything still debated is marked as such rather than presented as settled.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C4H9N3O2·H2O | Monohydrate form; anhydrous is C4H9N3O2 |
| Molar mass | 149.15 g/mol | For the monohydrate |
| Appearance | White crystalline powder | Odorless, slightly bitter taste |
| Solubility in water | ~13 g/L at 25 °C | Poorly soluble; increases with temperature |
| CAS Registry Number | 6020-87-7 | For creatine monohydrate |
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.
The compound was identified in the nineteenth century after chemists isolated a nitrogenous substance from meat extracts. Later work established its role in muscle energy metabolism and its conversion to phosphocreatine. Chemical synthesis of creatine followed, and industrial production made the monohydrate widely available as a purified powder. Interest expanded in the late twentieth century when researchers began studying creatine supplementation and muscle physiology. Historical accounts sometimes differ on exact dates and attributions, but the broad sequence from tissue extracts to synthetic production is well documented.
In the body, creatine is obtained from dietary meat and fish and is also synthesized from arginine, glycine, and methionine. Muscle stores creatine and phosphocreatine, which participate in the rapid regeneration of adenosine triphosphate during short, intense activity. The monohydrate form is used in research because it is chemically defined, stable as a dry solid, and relatively inexpensive to produce. Questions remain about whether other creatine forms offer meaningful advantages in absorption or tissue retention, and findings vary across studies and populations.
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.
Creatine monohydrate is one of several solid forms of creatine described in the literature. Other forms include anhydrous creatine, creatine hydrochloride, and creatine ethyl ester, each with different solubility and stability characteristics. The monohydrate is distinct from creatinine, a spontaneous breakdown compound that forms when creatine loses water and cyclizes. Commercial descriptions sometimes use synonyms such as methylguanidoacetic acid or N-(aminoiminomethyl)-N-methylglycine, which refer to the same base molecule. These names appear in chemical databases and product labels.
In molecular biology, the BSD domain is an approximately 60-amino-acid-long protein domain named after the BTF2-like transcription factors, synapse-associated proteins and DOS2-like proteins in which it is found. It is also found in several hypothetical proteins. It occurs in one or two copies in a variety of species ranging from primal protozoan to human, and can be found associated with other domains such as the BTB domain or the U-box in multidomain proteins. Its function is as yet unknown. Secondary structure prediction indicates the presence of three predicted alpha helices, which probably form a three-helical bundle in small |domains. The third predicted helix contains neighbouring phenylalanine and tryptophan residues—less common amino acids that are invariant in all the BSD domains identified and that are the domain's most striking sequence features. Some proteins known to contain one or two BSD domains are:
Sensory evoked potentials (SEP) are recorded from the central nervous system following stimulation of sense organs, for example, visual evoked potentials elicited by a flashing light or changing pattern on a monitor, auditory evoked potentials by a click or tone stimulus presented through earphones), or tactile or somatosensory evoked potential (SSEP) elicited by tactile or electrical stimulation of a sensory or mixed nerve in the periphery. Sensory evoked potentials have been widely used in clinical diagnostic medicine since the 1970s, and also in intraoperative neurophysiology monitoring (IONM), also known as surgical neurophysiology. There are three kinds of evoked potentials in widespread clinical use: auditory evoked potentials, usually recorded from the scalp but originating at brainstem level; visual evoked potentials, and somatosensory evoked potentials, which are elicited by electrical stimulation of peripheral nerve. Examples of SEP usage include:
The major practical problem of the entire proposal, however, was collecting the radioactive debris dispersed by the powerful blast. Aircraft filters adsorbed only about 4×10−14 of the total amount and collection of tons of corals at Enewetak Atoll increased this fraction by only two orders of magnitude. Extraction of about 500 kilograms of underground rocks 60 days after the Hutch explosion recovered only about 10−7 of the total charge. The amount of transuranium elements in this 500-kg batch was only 30 times higher than in a 0.4 kg rock picked up 7 days after the test. This observation demonstrated the highly nonlinear dependence of the transuranium elements yield on the amount of retrieved radioactive rock. In order to accelerate sample collection after the explosion, shafts were drilled at the site not after but before the test, so that the explosion would expel radioactive material from the epicenter, through the shafts, to collecting volumes near the surface. This method was tried in the Anacostia and Kennebec tests and instantly provided hundreds of kilograms of material, but with actinide concentrations 3 times lower than in samples obtained after drilling; whereas such a method could have been efficient in scientific studies of short-lived isotopes, it could not improve the overall collection efficiency of the produced actinides.
Sources: en.wikipedia.org
== History and taxonomy == The fungus was first isolated in 1870 from a tinea cruris patient in Germany by Carl Otto Harz, who named it Acrothecium floccosum. Being unaware of Harz's work, Castellani and Sabouraud identified the species again in 1905 and 1907, respectively, and both placed the fungus into the genus Epidermophyton. Epidermophyton is one of the three dermatophyte fungal genera; it is distinct from the other two genera (Microsporum and Trichophyton) for the absence of microconidia. In 1930, based on the principle of priority, Langeron and Milochevitch renamed the fungus Epidermophyton floccosum to recognize Harz's contribution in identifying the species first, as well as his extensive morphological descriptions. Another fungus, originally named Epidermophyton stockdaleae, is a dark-brown, soil-inhabiting species that is morphologically and molecularly distinct to E. floccosum for its longer conidia and 7% NaCl tolerance. E. stockdaleae is also clinically differentiated from E. floccosum by its ability in perforating hair. Due to the presence of microconidia, E. stockdaleae is now considered a synonym of Trichophyton ajelloi, hence E. floccosum is currently the only species in the genus Epidermophyton.
=== Other dipeptides === Homoanserine (N-(4-aminobutyryl)-L-histidine) is another dipeptide identified in the brain and muscles of mammals. Kyotorphin (L-tyrosyl-L-arginine) is a neuroactive dipeptide which plays a role in pain regulation in the brain. Balenine (or ophidine) (beta-alanyl-N tau-methyl histidine) has been identified in the muscles of several species of mammal (including man), and the chicken. Glorin (N-propionyl-γ-L-glutamyl-L-ornithine-δ-lac ethyl ester) is a chemotactic dipeptide for the slime mold Polysphondylium violaceum. Barettin (cyclo-[(6-bromo-8-en-tryptophan)-arginine]) is a cyclic dipeptide from the marine sponge Geodia barretti. Dialanine is commonly used as a model in molecular dynamics. Xenortides, isolated from the bacterium Xenorhabdus nematophila Oglufanide (H-L-Glu-Trp-OH, also known as Thymogen), immunomodulator researched for conditions including Hepatitis C.
=== Other uses === A 2003 meta-analysis of existing research showed naloxone to improve blood flow in patients with shock, including septic, cardiogenic, hemorrhagic, or spinal shock, but could not determine if this reduced patient deaths. Oral naloxone has been used for opioid-induced constipation (OIC). A 2018 meta-analysis cites 5 studies that tests it for this purpose. It found that medical treatment for OIC can be more efficacious than placebo, but did not look into the effect of individual treatments such as naloxone. As a result, no conclusion can be drawn from the study on naloxone's effectiveness for OIC. Naloxone and other opioid antagonists have been examined as possible treatments for dissociative disorders. This use predicates on the theory that dissociative disorders cause disregulation in the body's natural opioid pathways. A 2023 meta-analytic study found some evidence of opioid antagonists being effective against dissociative disorders, but possible publication bias and differences in testing criteria encourages additional research.
Sources: en.wikipedia.org
It is a compound made of creatine bound to one water molecule. It appears as a white crystalline powder and is the most common solid form of creatine used in research and supplements.
Creatine is converted to phosphocreatine in muscle, which helps regenerate adenosine triphosphate during brief, high-intensity activity. The body also obtains creatine from foods such as meat and fish.
The creatine molecule is the same whether from food or supplements, but the monohydrate form includes a water molecule in its crystal structure. Once dissolved, the monohydrate and food-derived creatine are chemically identical in the body.
Keep it in a sealed container in a cool, dry place away from direct heat and moisture. Dry powder is more stable than prepared solutions.