A practical reference on Guanidino group: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-07-03. Anything still debated is marked as such rather than presented as settled.
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.
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.
Creatine monohydrate is a crystalline compound formed from creatine and one molecule of water. Its systematic name is N-(aminoiminomethyl)-N-methylglycine monohydrate, and it appears as a white, odorless powder with limited solubility in water. The monohydrate is the most common solid form used in research and commercial products because it is stable under dry conditions. The anhydrous form lacks the water of crystallization and differs slightly in molar mass. Both forms participate in the same biochemical reactions once dissolved.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C4H9N3O2·H2O | Monohydrate; anhydrous base is C4H9N3O2 |
| Molar mass | 149.15 g/mol | Calculated for the monohydrate form |
| Appearance | White crystalline powder | Typical laboratory and food-grade material |
| Solubility in water | Sparingly soluble at room temperature | Solubility increases with temperature |
| Common synonyms | Methylguanidoacetic acid; N-(aminoiminomethyl)-N-methylglycine | Synonyms refer to the creatine base, not the hydrate specifically |
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.
Magnesium forms a variety of compounds important to industry and biology, including magnesium carbonate, magnesium chloride, magnesium citrate, magnesium hydroxide (milk of magnesia), magnesium oxide, magnesium sulfate, and magnesium sulfate heptahydrate (Epsom salts). As recently as 2020, magnesium hydride was under investigation as a way to store hydrogen.
In surface science, the term adhesion almost always refers to dispersive adhesion. In a typical solid-liquid-gas system (such as a drop of liquid on a solid surrounded by air) the contact angle is used to evaluate adhesiveness indirectly, while a Centrifugal Adhesion Balance allows for direct quantitative adhesion measurements. Generally, cases where the contact angle is low are considered of higher adhesion per unit area. This approach assumes that the lower contact angle corresponds to a higher surface energy. Theoretically, the more exact relation between contact angle and work of adhesion is more involved and is given by the Young-Dupre equation. The contact angle of the three-phase system is a function not only of dispersive adhesion (interaction between the molecules in the liquid and the molecules in the solid) but also cohesion (interaction between the liquid molecules themselves). Strong adhesion and weak cohesion results in a high degree of wetting, a lyophilic condition with low measured contact angles. Conversely, weak adhesion and strong cohesion results in lyophobic conditions with high measured contact angles and poor wetting. London dispersion forces are particularly useful for the function of adhesive devices, because they do not require either surface to have any permanent polarity. They were described in the 1930s by Fritz London, and have been observed by many researchers. Dispersive forces are a consequence of statistical quantum mechanics.
Jake Carlisle (born 1 October 1991) is a former professional Australian rules footballer who played 66 games for the St Kilda Football Club in the Australian Football League (AFL) until his retirement at the end of the 2021 season. He previously played 85 games for the Essendon Football Club from 2010 to 2015.
Sources: en.wikipedia.org
The earliest clear evidence of hair or fur is in fossils of Castorocauda and Megaconus, from 164 million years ago in the mid-Jurassic. In the 1950s, it was suggested that the foramina (passages) in the maxillae and premaxillae (bones in the front of the upper jaw) of cynodonts were channels which supplied blood vessels and nerves to vibrissae (whiskers) and so were evidence of hair or fur; it was soon pointed out, however, that foramina do not necessarily show that an animal had vibrissae, as the modern lizard Tupinambis has foramina that are almost identical to those found in the nonmammalian cynodont Thrinaxodon. Popular sources, nevertheless, continue to attribute whiskers to Thrinaxodon. Studies on Permian coprolites suggest that non-mammalian synapsids of the epoch already had fur, setting the evolution of hairs possibly as far back as dicynodonts. When endothermy first appeared in the evolution of mammals is uncertain, though it is generally agreed to have first evolved in non-mammalian therapsids. Modern monotremes have lower body temperatures and more variable metabolic rates than marsupials and placentals, but there is evidence that some of their ancestors, perhaps including ancestors of the therians, may have had body temperatures like those of modern therians. Likewise, some modern therians like afrotheres and xenarthrans have secondarily developed lower body temperatures. The evolution of erect limbs in mammals is incomplete—living and fossil monotremes have sprawling limbs.
==== Absorption ==== Doxepin is well-absorbed from the gastrointestinal tract but between 55 and 87% undergoes first-pass metabolism in the liver, resulting in a mean oral bioavailability of approximately 29%. Following a single very low dose of 6 mg, peak plasma levels of doxepin are 0.854 ng/mL (3.06 nmol/L) at 3 hours without food and 0.951 ng/mL (3.40 nmol/L) at 6 hours with food. Plasma concentrations of doxepin with antidepressant doses are far greater, ranging between 50 and 250 ng/mL (180 to 900 nmol/L). Area-under-curve levels of the drug are increased significantly when it is taken with food.
== History == Results of a Phase I clinical trial were reported in 2016. In December 2019, enfortumab vedotin was approved in the United States for the treatment of adult patients with locally advanced or metastatic urothelial cancer who had previously received a programmed cell death receptor-1 (PD-1) or programmed death ligand 1 (PD-L1) inhibitor and a platinum-containing chemotherapy. The approval was based on the results of a clinical trial of 125 such patients. The overall response rate, reflecting the percentage of patients who had a certain amount of tumor shrinkage, was 44%; specifically, 12% had a complete response and 32% a partial response. The median duration of response was 7.6 months. The U.S. Food and Drug Administration (FDA) granted the application for enfortumab vedotin accelerated approval, priority review designation, and breakthrough therapy designation. The FDA granted the approval of Padcev to Astellas Pharma US Inc. In July 2021, the FDA approved enfortumab vedotin for adults with locally advanced or metastatic urothelial cancer who have previously received a PD-1 or PD-L1 inhibitor and platinum-containing chemotherapy, or who are ineligible for cisplatin-containing chemotherapy and have previously received therapy.
Sources: en.wikipedia.org
Creatine monohydrate is the hydrated solid form of creatine, a nitrogen-containing compound involved in cellular energy metabolism. It consists of one creatine molecule associated with one water molecule in a crystal lattice.
No. Creatinine is a breakdown product formed when creatine loses water and cyclizes, and it is not the same compound. The two names are similar but refer to different chemical structures and roles.
The body synthesizes creatine from amino acids, mainly in the liver and kidneys. It also comes from animal foods such as meat and fish, while plant foods contain little or none.
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.