A practical reference on creatine: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-12-09 and is reviewed periodically as new material appears.
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.
Stability studies examine how creatine monohydrate changes under controlled temperature and humidity. The solid is generally stable when kept dry, but moisture can promote hydrolysis to creatinine, especially in solution or at elevated temperatures. Color, odor, and assay values are monitored over time to detect degradation. Because degradation pathways depend on storage conditions, shelf-life claims should specify the tested packaging, temperature, and humidity. Open questions remain about the long-term behavior of different crystal habits and particle sizes.
Regulatory treatment of creatine monohydrate varies by country and intended use. In some jurisdictions it is sold as a dietary supplement, while in others it may be treated as a food ingredient or a pharmaceutical raw material. Pharmacopeial monographs, where available, define identification, assay limits, and impurity thresholds. Manufacturers often follow these monographs or internal specifications to ensure batch-to-batch consistency. Analytical method validation is important because different methods can yield different apparent purity values if sample preparation or detection conditions are not controlled.
Quality control for creatine monohydrate begins with identity confirmation and assay determination. Laboratories commonly use high-performance liquid chromatography with ultraviolet detection, often after derivatization or using a suitable column, to quantify creatine. Karl Fischer titration measures water content, which helps verify the monohydrate stoichiometry. Additional tests screen for heavy metals, residual solvents, and microbial contamination depending on the intended use. These tests establish composition and purity rather than biological effect.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | 15–25 °C | Protect from moisture, heat, and direct sunlight |
| Analytical method | HPLC with UV or RI detection | Separates creatine from creatinine and related impurities |
| Water content | About 12.1% w/w | Theoretical value for the monohydrate crystal |
| Degradation product | Creatinine | Formed by cyclization, especially in aqueous solution |
| Common assay specification | 98.0–102.0% | Range depends on the testing method and monograph |
Creatine was first identified in skeletal muscle extracts in the nineteenth century, and its role in phosphagen energy buffering was clarified in the twentieth century. The monohydrate salt became widely studied after methods for inexpensive synthesis and crystallization were developed. Modern research examines its effects on muscle energetics, recovery, and cognitive performance under specific conditions. Findings vary with population, exercise protocol, baseline creatine status, and measurement method. Studies often compare supplementation with placebo during controlled training or testing schedules.
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.
Durston had attempted to treat Travers with salivation, which he believed reduced her breasts slightly but which she did not like as a treatment option, and then cauterization followed by incision by knife in the hope that excess fluid would be found to drain, but this was unsuccessful as it was healthy breast tissue, notable only for its massive enlargement and thus lacking excess fluid to drain.
== External links == Silva P. "The chemical logic behind fatty acid metabolism". Universidade Fernando Pessoa. Archived from the original on 16 March 2010. "Fatty acid oxidation animation". Cengage Learning. Archived from the original on 2012-05-08. Retrieved 2007-05-02. Jain, P.; Singh, S.; Arya, A. (2021). "Integrated formulae for calculating fatty acid ATP yield". Biochemistry and Molecular Biology Education. 49 (3): 492–499. doi:10.1002/bmb.21486. PMID 33427394. S2CID 231577993.
. Stress intensity replaced strain energy release rate and a term called fracture toughness replaced surface weakness energy. Both of these terms are simply related to the energy terms that Griffith used:
The Mercedes-Benz OM601 engine is an inline-four diesel engine that was manufactured by Mercedes-Benz from 1983 to 2000. It is the successor to the OM616 engine and was succeeded by the OM604 engine in 1993.
Sources: en.wikipedia.org
we discovered an isotope of great scientific interest, because it decayed by means of an isomeric transition with emission of a line spectrum of electrons coming from an almost completely internally converted gamma ray transition. [actually, only 12% of the decays are by internal conversion] (...) This was a form of radioactive decay which had never been observed before this time. Segrè and I were able to show that this radioactive isotope of the element with the atomic number 43 decayed with a half-life of 6.6 h [later updated to 6.0 h] and that it was the daughter of a 67-h [later updated to 66 h] molybdenum parent radioactivity. This chain of decay was later shown to have the mass number 99, and (...) the 6.6-h activity acquired the designation 'technetium-99m. Later in 1940, Emilio Segrè and Chien-Shiung Wu published experimental results of an analysis of fission products of uranium-235, including molybdenum-99, and detected the presence of an isomer of element 43 with a 6-hour half-life, later labelled as technetium-99m.
As a medication, insulin is any pharmaceutical preparation of the protein hormone insulin that is used to treat high blood glucose. Such conditions include type 1 diabetes, type 2 diabetes, gestational diabetes, and complications of diabetes such as diabetic ketoacidosis and hyperosmolar hyperglycemic states. Insulin is also used along with glucose to treat hyperkalemia (high blood potassium levels). Typically it is given by injection under the skin, but some forms may also be used by injection into a vein or muscle. There are various types of insulin, suitable for various time spans. The types are often all called insulin in the broad sense, although in a more precise sense, insulin is identical to the naturally occurring molecule whereas insulin analogues have slightly different molecules that allow for modified time of action. It is on the World Health Organization's List of Essential Medicines. In 2023, it was the 157th most commonly prescribed medication in the United States, with more than 3 million prescriptions. Insulin can be made from the pancreas of pigs or cows. Human versions can be made either by modifying pig versions, or recombinant technology using mainly E. coli or Saccharomyces cerevisiae. It comes in three main types: short–acting (such as regular insulin), intermediate-acting (such as neutral protamine Hagedorn (NPH) insulin), and longer-acting (such as insulin glargine).
The investigation had found out that in the period of 2004-2009, Gobozov was giving secret information on the deployment the military units of the Russian Ministry of Defence and the Border Service of the FSB on the South Ossetian territory to the secret services of Georgia. However, according to the agreement between Russia and Georgia, only the presence of the Russian contingent of the Joint Peacekeeping Forces was allowed in South Ossetia and their number, staff composition, equipment, places of deployment and every movement should have been known to Tbilisi. Thus, the Prosecutor General's Office of the Russian Federation admitted that non-peacekeeping Russian troops were present on the South Ossetian territory (which Russia then considered as the Georgian territory) without Tbilisi's consent before the war in August 2008. Russian journalist Yulia Latynina commented that by acknowledging the presence of the Russian troops on the de jure Georgian territory from 2004 to 2008, the Prosecutor General's Office of Russia admitted the crime of aggression of Russia. In 2012, Anatoly Khrulyov, the commander of the 58th Army, said in an interview that "For me, the war began in my workplace." He said that the decision to reinforce the Russian peacekeeping force was made on 5 August 2008. Khrulyov said that Marat Kulakhmetov, commander of the Joint Peacekeeping Forces called him on the night of 7–8 August and said that General Mamuka Kurashvili had warned him that Georgia was going to launch a large-scale military operation.
==== Ciclosporin ==== Ciclosporin is an immunosuppressive agent most often used in organ transplantation that has demonstrated to be effective with skin disorders. It functions by lessening production of autoantibodies and therefore diminishing the development of blisters and erosions. The mechanism of action is by inhibiting the production of T lymphocytes and lymphokines.
=== Sale to Sidney Feltenstein; Grotech subsidiary === In December 1994, Taubman sold A&W to Sidney Feltenstein, with the aim of pushing the chain's international expansion further, while still maintaining its headquarters in Livonia. At the time, there were 790 restaurants (688 in the United States and 102 abroad), with the bulk of the international locations located in Malaysia, Thailand and Japan, as well as in Mexico and the United Arab Emirates. Earlier in 1994, its hundredth international location opened at a tourist attraction in Bangkok: a crocodile farm. In January 1995, operations were taken over by Grotech Capital Partners, for a sum of $20 million, with Feltenstein as the chain's new CEO. An agreement was signed in 1996 with Walmart to provide restaurants in seven locations. The menu would add items depending on the region, with the rest being its standard fare. That year, its restaurants were renovated to feature an aesthetic referred to by Feltenstein as "contemporary nostalgia". The move mirrored that of Dairy Queen, which had also opened a test location with a similar feel. A&W also operated restaurants in Monterrey, a key city in northern Mexico. In 1997, A&W acquired Carousel Snack Bars, including its 175 units in malls. The agreement made the chain the owner of these units, while continuing to franchise restaurants.
Sources: en.wikipedia.org
A majority of Generation Z disagreed that it was necessary to raise children in a religious household, and only a minority deemed religion to be an important part of their lives. On the other hand, the Pew Research Center found the gap in spirituality among the old and the young to be more modest. In a 2016 poll, Barna found that Millennials and Generation Z were equally likely to require factual evidence before believing in something and to consider the Bible to be at odds with science. The same Barna survey revealed that the percentage of atheists and agnostics was 21% among Generation Z, higher than all previous cohorts. Moreover, whereas in the past, women were broadly more religious than men, during the 2020s, young women secularizing faster than young men, and have become just about as religious as men. Youths who still hold private religious beliefs are also less likely to go to church. When asked what their biggest barriers to faith were, irreligious members of Generation Z pointed to what they perceived as internal contradictions of the religion and its believers. Many also took issue with religious leaders' positions on certain social and political topics, such as abortion, homosexuality, and sex-abuse scandals of the Church. Young women in particular disapproved of the Church's emphasis on traditional gender roles, especially the subservience of women before men, and the culture of purity, such as the insistence that women must dress "modestly" because they were responsible for the thoughts of men.
== History == Sperm washing was first used in Milan, Italy. The oldest child conceived using this method was born in 1997 and is HIV negative. The first known baby conceived this way in the United States, Baby Ryan, was born in 1999 through the Special Program of Assisted Reproduction started by Ann Kiessling. Starting in the mid-1990s the technique was used to help HIV discordant couples conceive without passing the virus from the father to the mother or child. The idea is that when the male is HIV positive, the technique will reduce the risk of transmission to the female. For years there were lingering doubts about the safety of the procedure, and many couples had to travel to places that would do the procedure, such as Italy. Today, hundreds of babies have been born through this process.
== External links == Signal+Peptide at the U.S. National Library of Medicine Medical Subject Headings (MeSH) SPdb (Signal Peptide DataBase) Archived 2016-01-22 at the Wayback Machine SignalP — predicts the presence and location of signal peptide cleavage sites in amino acid sequences from different organisms.
=== Development discontinued === AV-608 (CGP-60829; NK-608; NKP-608C; NKP608) – neurokinin NK1 receptor antagonist Cycloserine (D-cycloserine; TIK-101; TIK101) — NMDA receptor partial agonist Tradipitant (LY-686017; VLY-686) – neurokinin NK1 receptor antagonist Verucerfont (GSK-561679; NBI-77860) – corticotropin-releasing hormone receptor 1 (CRF1) antagonist
characterizes the potential for initial spread of an infectious person in a naive population, assuming the change in the susceptible population is negligible during the initial spread. A linear system of ODEs can always be described by a matrix. So, the next step is to construct a linear positive operator that provides the next generation of infected people when applied to the present generation. Note that this operator (matrix) is responsible for the number of infected people, not all the compartments. Iteration of this operator describes the initial progression of infection within the heterogeneous population. So comparing the spectral radius of this operator to unity determines whether the generations of infected people grow or not.
Sources: en.wikipedia.org
Purity testing often uses high-performance liquid chromatography to measure creatine and creatinine. Water content can be checked by Karl Fischer titration. Additional tests may cover heavy metals, residual solvents, and microbial contamination.
In solution, creatine can cyclize spontaneously to creatinine. Heat and certain pH conditions increase the rate of this conversion. Dry crystalline material is more stable because the reaction requires water.
Typical storage is in a sealed container at room temperature, away from moisture and direct heat. These conditions reduce caking and slow degradation. Liquid products require more careful handling because creatine is less stable in water.
Karl Fischer titration is a standard method for measuring water content in solid and liquid samples. The result helps confirm the expected monohydrate stoichiometry. Loss-on-drying can also indicate moisture but may not distinguish water from other volatile substances.