The short version of Guanidinium group fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-12-12. Anything still debated is marked as such rather than presented as settled.
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 dry and protected from extremes of heat and humidity. In the presence of moisture, it can gradually convert to creatinine, a cyclic dehydration product that has little value for phosphocreatine synthesis. Elevated temperatures and acidic conditions accelerate this conversion in solution. Because the reaction is slow in cool, dry storage, typical shelf lives are measured in years rather than weeks. Packaging that limits moisture and oxygen exposure helps maintain purity.
Recommended storage usually involves a sealed container kept at room temperature, away from direct sunlight and moisture. High humidity can cause caking, which changes flow properties and may complicate accurate weighing. Repeated opening of containers exposes the powder to air and moisture, so smaller aliquots can reduce handling effects. Storage temperature ranges are not absolute requirements; they reflect conditions that slow degradation and preserve consistent physical characteristics. Clean, dry tools help prevent contamination during sampling.
| 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. |
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 the body, creatine is synthesized from arginine, glycine, and methionine, mainly in the liver and kidneys, and is also obtained from foods such as meat and fish. About 95% of body creatine is stored in skeletal muscle, where a fraction is phosphorylated to phosphocreatine. Phosphocreatine serves as a rapid reserve of high-energy phosphate for short bursts of ATP regeneration. The monohydrate form supplies creatine after dissolution and absorption, but it is not itself the active phosphorylated species.
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.
== Epidemiology == Gynecomastia is the most common benign disorder of the male breast tissue and affects 35 percent of men, being most prevalent between the ages of 50 and 69. New cases of gynecomastia are common in three age populations: newborns, adolescents, and men older than 50 years. Newborn gynecomastia occurs in about 60–90 percent of male babies, and most cases resolve on their own in about 2–3 weeks after delivery. During adolescence, on average, 33 percent of males are estimated to exhibit signs of gynecomastia. Gynecomastia in older men is estimated to be present in 24–65 percent of men between the ages of 50 and 80. Estimates on asymptomatic gynecomastia are about up to 70% in men aged 50 to 69 years. The prevalence of gynecomastia in men may have increased in recent years, but the epidemiology of the disorder is not fully understood. The use of anabolic steroids and exposure to chemicals that mimic estrogen in cosmetic products, organochlorine pesticides, and industrial chemicals have been suggested as possible factors driving this increase. According to the American Society of Plastic Surgeons, breast reduction surgeries to correct gynecomastia are fairly common but has been a recent decline. In 2020, there were over 18,000 procedures of this type performed in the United States, which is down 11% from 2019.
== Art == The continuity of the deep fasciae within the human body inspired the artistic expression seen in the Fascial Net Plastination Project, which is prominently displayed at the Body Worlds exhibition in Berlin.
=== Media === In literature, characters believed to exhibit signs of BPD include Catherine in Wuthering Heights (1847), Smerdyakov in The Brothers Karamazov (1880), and Harry Haller in Steppenwolf (1927). Films have also attempted to portray BPD, with characters in Margot at the Wedding (2007), Mr. Nobody (2009), Cracks (2009), Truth (2013), Wounded (2013), Welcome to Me (2014), and Tamasha (2015) all suggested to show traits of the disorder. The behavior of Theresa Dunn in Looking for Mr. Goodbar (1975) is consistent with BPD, as suggested by Robert O. Friedel. Films like Play Misty for Me (1971) and Girl, Interrupted (1999, based on the memoir of the same name) suggest emotional instability characteristic of BPD, while Single White Female (1992) highlights aspects such as identity disturbance and fear of abandonment. Clementine in Eternal Sunshine of the Spotless Mind (2004) is noted to show classic BPD behavior, and Carey Mulligan's portrayal in Shame (2011) is praised by psychiatrists for its accuracy regarding BPD characteristics. Television series like Crazy Ex-Girlfriend (2015) and the miniseries Maniac (2018) depict characters with BPD. Traits of BPD and narcissistic personality disorders are observed in characters like Cersei and Jaime Lannister from A Song of Ice and Fire (1996) and its TV adaptation Game of Thrones (2011). In The Sopranos (1999), Livia Soprano is diagnosed with BPD, and even the portrayal of Bruce Wayne/Batman in the show Titans (2018) is said to include aspects of the disorder.
Sources: en.wikipedia.org
One of the most prominent campaigners was a young man from East Germany called Rudi Dutschke who also criticised the forms of capitalism that were to be seen in West Berlin. Just before Easter 1968, a young man tried to kill Dutschke as he bicycled to the student union, seriously injuring him. All over West Germany, thousands demonstrated against the Springer newspapers which were seen as the prime cause of the violence against students. Trucks carrying newspapers were set on fire and windows in office buildings broken. In the wake of these demonstrations, in which the question of America's role in Vietnam began to play a bigger role, came a desire among the students to find out more about the role of the parent-generation in the Nazi era. The proceedings of the War Crimes Tribunal at Nuremberg had been widely publicised in Germany; the attorney Fritz Bauer gathered evidence on the guards of the Auschwitz concentration camp, and about twenty were put on trial in Frankfurt in 1963. Daily newspaper reports and visits by school classes to the proceedings revealed to the German public the nature of the concentration camp system, and it became evident that the Shoah was of vastly greater dimensions than the German population had believed. The term "Holocaust" for the systematic mass-murder of Jews first came into use in 1979, when a 1978 American mini-series with that name was shown on West German television. The processes set in motion by the Auschwitz trial reverberated decades later.
==== MeSH D12.776.624.776.355 – cyclin-dependent kinase inhibitor proteins ==== MeSH D12.776.624.776.355.100 – cyclin-dependent kinase inhibitor p15 MeSH D12.776.624.776.355.200 – cyclin-dependent kinase inhibitor p16 MeSH D12.776.624.776.355.300 – cyclin-dependent kinase inhibitor p18 MeSH D12.776.624.776.355.400 – cyclin-dependent kinase inhibitor p19 MeSH D12.776.624.776.355.500 – cyclin-dependent kinase inhibitor p21 MeSH D12.776.624.776.355.600 – cyclin-dependent kinase inhibitor p27 MeSH D12.776.624.776.355.700 – cyclin-dependent kinase inhibitor p57
=== Fentanyl analogs === Fentanyl analogs are types of fentanyl with various chemical modifications on any number of positions of the molecule, but still maintain, or even exceed, its pharmacological effects. Many fentanyl analogs are termed "designer drugs" because they are synthesized solely to be used illicitly. Carfentanil, a fentanyl analog, has an additional methyl ester group attached to the 4 position. Carfentanil is 20–30 times as potent as fentanyl and is common in the illicit drug chain. The drug is commonly used to tranquilize elephants and other large animals.
Sources: en.wikipedia.org
Copanlisib, sold under the brand name Aliqopa, is a medication used for the treatment of adults experiencing relapsed follicular lymphoma who have received at least two prior systemic therapies. In November 2023, Bayer announced that it was withdrawing copanlisib from the United States market after the drug's phase III trial, CHRONOS-4, failed to establish confirmation of clinical benefits as sought by the Food and Drug Administration.
==== Uses ==== As mentioned in the section Pathway systems, there were several uses for the Inca roads. The most obvious way in which the Inca people used the road/trail systems was to transport goods. They did this on foot and sometimes with the help of animals (llamas and alpacas). Not only were goods transported throughout the vast empire, but so were ideas and messages. The Inca needed a system of communication, so they relied on Chasquis, otherwise known as messengers. The Chasquis were chosen among the strongest and fittest young males. They ran several miles per day, only to deliver messages. These messengers resided in cabins called "tambos." These structures were positioned along the roads and built by the Inca people. These buildings provided the Chasquis with a place to rest. These places of rest could also be used to house the Inca army in a situation of rebellion or war.
In 1882, Lord Rayleigh theoretically estimated the maximum amount of charge a liquid droplet could carry before throwing out fine jets of liquid. This is now known as the Rayleigh limit. In 1914, John Zeleny published work on the behaviour of fluid droplets at the end of glass capillaries and presented evidence for different electrospray modes. Wilson and Taylor and Nolan investigated electrospray in the 1920s and Macky in 1931. The electrospray cone (now known as the Taylor cone) was described by Sir Geoffrey Ingram Taylor. The first use of electrospray ionization with mass spectrometry was reported by Malcolm Dole in 1968. John Bennett Fenn was awarded the 2002 Nobel Prize in Chemistry for the development of electrospray ionization mass spectrometry in the late 1980s.
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.
Solid product can remain within specification for years when stored dry and sealed, but expiration dates reflect manufacturer testing and regulatory conventions. Moisture and heat increase conversion to creatinine, so storage conditions matter more than the printed date alone. Degradation is gradual and can be monitored by purity testing.