This is a working overview of hygroscopicity, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
Creatine monohydrate is sold as a dietary ingredient in some countries and as a food supplement in others. Regulatory frameworks vary, so purity limits, labeling rules, and permitted claims are not globally uniform. In the United States, it falls under dietary supplement rules, whereas the European Union treats it as a food supplement ingredient. Pharmacopeial monographs, where they exist, can provide public quality standards, but not every product is required to meet them. Questions about long-term effects and patterns of use remain areas of active study rather than settled regulatory findings.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Purity (typical) | ≥99% by HPLC | Supplement and pharmacopeial grades vary |
| Water content | ≈12.1% theoretical | Measured by Karl Fischer titration |
| Creatinine limit | Often ≤0.1% in pharmacopeial grade | Supplement specifications may differ |
| Storage conditions | 15–25 °C, low humidity | Away from heat and acidic environments |
| Common analytical methods | HPLC–UV, NMR, FTIR, Karl Fischer | Used for identity, assay, and water content |
Sourcing and verification of creatine monohydrate involve both manufacturing origin and third-party testing. Industrial production commonly starts with sarcosine and cyanamide, followed by crystallization to obtain the monohydrate. Some products are derived from animal sources, while others are synthesized from non-animal precursors. Certificates of analysis report assay, heavy metals, and microbial limits. Regulations differ by country: in the United States it is sold as a dietary supplement, whereas in the European Union it falls under food supplement rules.
In solid form, creatine monohydrate is relatively stable when kept dry and away from heat. Moisture and elevated temperatures promote cyclization into creatinine, a related compound with no role in the phosphagen system. Degradation accelerates in aqueous solution, where the conversion can occur within hours to days depending on pH and temperature. Manufacturers typically recommend storage in sealed containers at room temperature, with relative humidity below 50 percent. Long-term stability data for opened containers are limited.
Several creatine forms are sold, including monohydrate, anhydrous, hydrochloride, nitrate, citrate, and blends. Once dissolved, these forms deliver creatine, but they differ in molar mass, solubility, counterions, and water content. Creatine monohydrate has the largest body of published human data among these forms. Questions remain about whether any alternative form offers meaningful advantages in absorption, tolerability, or tissue uptake under practical conditions. The hydrate form's lower creatine content by mass is a compositional fact, not a statement about effectiveness.
Creatine monohydrate is a crystalline compound formed when one molecule of creatine associates with one molecule of water in the solid lattice. Its molecular formula is C4H11N3O3, and its molar mass is about 149.15 grams per mole. The material appears as a white, odorless powder that dissolves sparingly in water at room temperature. The monohydrate designation distinguishes it from anhydrous creatine, which lacks the bound water and has a lower molar mass. This hydrate is the most common commercial form of creatine used in nutritional and research settings.
Creatine is synthesized endogenously in humans, mainly in the liver, kidney, and pancreas, from the amino acids arginine, glycine, and methionine. Skeletal muscle stores much of the body's creatine, where it participates in the phosphocreatine system that buffers adenosine triphosphate during short, intense contractions. Dietary sources include meat and fish, so omnivorous diets provide additional creatine beyond endogenous production. Supplemental creatine monohydrate supplies the same molecule found in food and tissues, not a distinct drug or hormone. Research interest centers on its role in cellular energy transfer and its effects on muscle and other tissues.
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.
Handling practices aim to limit moisture uptake and thermal exposure. Containers should stay closed when not in use, and storage areas should avoid direct sunlight, strong heat, and high humidity. Caking can occur when powder absorbs water, even if the creatine itself has not fully degraded. Aqueous stock solutions are best prepared fresh when needed because they are less stable than the solid. Open questions include how different excipients, packaging materials, and climate conditions affect long-term stability across global supply chains.
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.
Football is the most popular sport in Romania with over 219,000 registered players as of 2018. The market for professional football in Romania was roughly €740 million in 2018 according to UEFA. The governing body is the Romanian Football Federation, which belongs to UEFA. The Romania national football team played its first match in 1922 and is one of only four national teams to have taken part in the first three FIFA World Cups, the other three being Brazil, France, and Belgium. Overall, it has played in seven World Cups and had its most successful period during the 1990s, when it finished 6th at the 1994 FIFA World Cup, eventually being ranked 3rd by FIFA in 1997. The most successful club is Steaua București, who were the first Eastern European team to win the UEFA Champions League in 1986, and were runners-up in 1989. Dinamo București reached the UEFA Champions League semi-final in 1984 and the UEFA Cup Winners' Cup semi-final in 1990. Other important Romanian football clubs are Rapid București, UTA Arad, Universitatea Craiova, Petrolul Ploiești, CFR Cluj, Astra Giurgiu, and Viitorul Constanța (the latter having recently merged with FCV Farul Constanța). Tennis is the second most popular sport. Romania reached the Davis Cup finals three times in 1969, 1971 and 1972. The second most popular team sport is handball. The men's team won the handball world championship in 1961, 1964, 1970, 1974 making them the third most successful nation ever in the tournament.
"Lobotomy's back" : 1997 article on cingulotomy in Discover magazine "Leucotomy: a qualified defence of ‘then’": 2001 article in QJM by psychiatrist John Sutton Pippard "My Lobotomy": 2005 Soundportraits.org interview with Sallie Ellen Ionesco, the first recipient of a lobotomy in 1946 "'My Lobotomy': Howard Dully's Journey": 2005 interview with the author of My Lobotomy "Mental Cruelty": 2006 Sunday Times article on lobotomy and contemporary psychosurgery in the United Kingdom "Nobel Panel Urged to Rescind Prize for Lobotomies": 2005 article on the Nobel Prize in Physiology or Medicine awarded to Egas Moniz "Ten Notable Lobotomies": 2009 compilation of biographies of lobotomy patients in Listverse The Lobotomists: 2011 BBC Radio 4 documentary on the history of lobotomy
== Prokaryotic == Prokaryotes use one type of RNA polymerase, transcribing mRNAs that code for more than one type of protein. Transcription, translation and mRNA degradation all happen simultaneously. Transcription termination is essential to define boundaries in transcriptional units, a function necessary to maintain the integrity of the strands and provide quality control. Termination in E. coli may be Rho dependent, utilizing Rho factor, or Rho independent, also known as intrinsic termination. Although most operons in DNA are Rho independent, Rho dependent termination is also essential to maintain correct transcription. ρ factor The Rho protein is an RNA translocase that recognizes a cytosine-rich region of the elongating mRNA, but the exact features of the recognized sequences and how the cleaving takes place remain unknown. Rho forms a ring-shaped hexamer and advances along the mRNA, hydrolyzing ATP toward RNA polymerase (5' to 3' with respect to the mRNA). When the Rho protein reaches the RNA polymerase complex, transcription is terminated by dissociation of the RNA polymerase from the DNA. The structure and activity of the Rho protein is similar to that of the F1 subunit of ATP synthase, supporting the theory that the two share an evolutionary link. Rho factor is widely present in different bacterial sequences and is responsible for the genetic polarity in E. coli. It works as a sensor of translational status, inhibiting non-productive transcriptions, suppressing antisense transcriptions and resolving conflicts that happen between transcription and replication.
Therapeutic monoclonal antibodies (mAbs) are used for several diseases, including cancer and Rheumatoid arthritis. Consequently, the high immunogenicity limited efficacy and was associated with severe infusion reactions. Although the exact mechanism is unclear, it is suspected that the mAbs are inducing infusion reactions by eliciting antibody antigen interactions, such as increased formation of immunoglobulin E (IgE) antibodies, which may bind onto mast cells and subsequent degranulation, causing allergy-like symptoms as well as the release of additional cytokines. Several innovations in genetic engineering has resulted in the decrease in immunogenicity, (also known as deimmunization), of mAbs. Genetic engineering has led to the generation of humanized and chimeric antibodies, by exchanging the murine constant and complementary regions of the immunoglobulin chains with the human counterparts. Although this has reduced the sometimes extreme immunogenicity associated with murine mAbs, the anticipation that all fully human mAbs would have not possess unwanted immunogenic properties remains unfulfilled.
=== Streptavidin gel-shift === Extent of biotinylation can also be measured by streptavidin gel-shift, since streptavidin remains bound to biotin during agarose gel electrophoresis or polyacrylamide gel electrophoresis. The proportion of target biotinylated can be measured via the change in band intensity of the target with or without excess streptavidin, seen quickly and quantitatively for biotinylated proteins by Coomassie brilliant blue staining.
Sources: en.wikipedia.org
== Physical properties == Hydrogen bonding significantly influences the properties of primary and secondary amines. For example, methyl and ethyl amines are gases under standard conditions, whereas the corresponding methyl and ethyl alcohols are liquids. Amines possess a characteristic ammonia smell, liquid amines have a distinctive "fishy" and foul smell. The nitrogen atom features a lone electron pair that can bind H+ to form an ammonium ion R3NH+. The lone electron pair is represented in this article by two dots above or next to the N. The water solubility of simple amines is enhanced by hydrogen bonding involving these lone electron pairs. Typically salts of ammonium compounds exhibit the following order of solubility in water: primary ammonium (RNH+3) > secondary ammonium (R2NH+2) > tertiary ammonium (R3NH+). Small aliphatic amines display significant solubility in many solvents, whereas those with large substituents are lipophilic. Aromatic amines, such as aniline, have their lone pair electrons conjugated into the benzene ring, thus their tendency to engage in hydrogen bonding is diminished. Their boiling points are high and their solubility in water is low.
== Applications == Sephadex is used to separate molecules by molecular weight. Sephadex is a faster alternative to dialysis (de-salting), requiring a low dilution factor (as little as 1.4:1), with high activity recoveries. Sephadex is also used for buffer exchange and the removal of small molecules during the preparation of large biomolecules, such as ampholytes, detergents, radioactive or fluorescent labels, and phenol (during DNA purification). A special hydroxypropylated form of Sephadex resin, named Sephadex LH-20, is used for the separation and purification of small organic molecules such as steroids, terpenoids, lipids. An example of use is the purification of cholesterol.
=== Platelet derived growth factor === The majority of the substrates of platelet-derived growth factor (PDGF) exhibit similar structures to Src Homology 2 domain. These substrates will bind to the PDGFR receptors which will dimerize and autophosphorylate. This phosphorylation attracted PLC-gamma (induces cell proliferation), Ras (which goes through signaling cascade and acts as a transcription factor), phosphatidylinositol 3-kinase (PI3K) which also promotes a signaling cascade inducing transcription factors, and stress fiber formation, and induces the STAT pathway which activates transcription factors.
In 2016, investigations into transatlantic drug trafficking revealed that the Kinahan Clan, Ireland's largest drug traffickers, had joined with prominent figures in Mexico, South America, West Africa, and Europe to form an informal "Super Cartel." However, the extent of its coordination remains unclear. The 2017 wedding of Daniel Kinahan in Dubai helped investigators identify key members such as Ridouan Taghi, Ricardo Riquelme Vega, Naoufal Fassih, and Camorra boss Raffaele Imperiale. In 2022–23, a major international operation led to 49 arrests, including traffickers Edin "Tito" Gacanin and Zuhair Belkhair, accused of moving large amounts of cocaine through Rotterdam; though many members of the "Super Cartel" remain in custody, both were released shortly after their arrests.
Gas-sampling sources include flame (atom source), inductively-coupled plasma (atom and ion source), microwave plasma (atom and ion source), direct-current plasma (atom and ion source), and glow discharge (atom and ion source).
Sources: en.wikipedia.org
== Chemical structure == The chemical structure of sodium stibogluconate is somewhat ambiguous, and the structure shown above is idealized. Its solutions may contain multiple antimony compounds, although this heterogeneity may be unimportant. It has been speculated that the active species contains only a single antimony centre.
The creation of artificial neurons that can receive and release dopamine (chemical signals rather than electrical signals) and communicate with natural rat muscle and brain cells is reported, with potential for use in BCIs/prosthetics. A screening AI system for many cancer types that integrates different types of data via multimodal learning is reported.
She remained in Australia for the next decade, discovering a number of new plant and animal species in the process, but also became notorious in later years for her removal of Aboriginal skeletons – and the possible incitement of violence against Aboriginal people – for anthropological research purposes. 1865: English geologist Elizabeth Carne was elected the first female Fellow of the Royal Geological Society of Cornwall. 1869: British physician and suffragist Sophia Jex-Blake led the successful campaign for women to be allowed to enrol in university medical training in the UK. Subsequently the University of Edinburgh became the first British university to admit women and Jex-Blake became the first practising female doctor in Scotland.
Elly Crampton Chuquimia Quiñones-Tancara, Aymara name Chuquimamani-Condori, is an American electronic music artist, poet and composer. Their music, which combines elements of Andean music and cumbia with electronic music and American genres like crunk and R&B, explores Andean cultural concepts and Latin American queer theory. They make up one half of Los Thuthanaka, along with their brother Joshua Chuquimia Crampton. The two siblings identify with the Pakajaqi nation of Aymara people. In 2025, they were awarded the Venice Biennale Silver Lion award following the release of Los Thuthanaka's self-titled album that spring. The album was named by Pitchfork as the best album of 2025.
=== Inhibitors === Ferroptosis can be inhibited by lipophilic radical trapping antioxidants such as ferrostatin-1, liproxstatin-1, and vitamin E. Chelation of iron by agents such as desferrioxamine mesylate (DFO) also prevents lipid peroxidation and suppresses ferroptosis.
Sources: en.wikipedia.org
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.
Creatinine is a degradation product formed when creatine loses water and cyclizes. It can appear during storage, processing, or analysis if conditions are harsh. Quality specifications often set a maximum limit for creatinine to control purity.
No universal testing protocol applies across all markets. Some products follow pharmacopeial monographs, while others rely on manufacturer specifications and third-party certificates. Common tests include assay, water content, heavy metals, and microbial limits.
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.