This is a working overview of creatinine, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-09-14. Anything still debated is marked as such rather than presented as settled.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | Creatine hydrate; N-carbamimidoyl-N-methylglycine monohydrate | Synonyms vary by naming convention |
| Typical assay method | HPLC-UV | Often paired with a reference standard |
| Water content method | Karl Fischer titration | Confirms monohydrate stoichiometry |
| Degradation product | Creatinine | Forms more readily in solution and with heat |
| Typical storage temperature | 15–25 °C | Keep dry and away from direct sunlight |
Regulatory status varies by country. In the United States, creatine monohydrate is sold as a dietary supplement ingredient, while in the European Union it is placed on the market as a food supplement component. Some jurisdictions have established purity monographs or permitted health claims, while others treat it as a novel food or require notification. Product labels may state the amount of creatine monohydrate or the equivalent creatine content, and the two figures can differ. Independent testing programs sometimes check identity, potency, and contaminant limits.
Creatine monohydrate is stable under dry, cool conditions but can degrade when exposed to moisture and heat. In solution, it undergoes hydrolysis to creatinine, a cyclic derivative with little role in phosphagen energy transfer. The rate of conversion increases with temperature, storage time, and acidic or alkaline pH. Solid material kept in a sealed container at room temperature generally retains its composition for extended periods. Moisture uptake is a primary concern because it can accelerate breakdown and caking.
In aqueous solution, creatine monohydrate undergoes a slow conversion to creatinine, a cyclized degradation product. This reaction is pH- and temperature-dependent, and it proceeds faster in warm or alkaline conditions. Because the conversion is gradual, analytical measurements of creatine in solution must account for time and storage history. The equilibrium favors creatinine more strongly at higher temperatures, which is relevant to sample handling in laboratories and to beverage formulations. Refrigeration slows but does not entirely stop this process.
Quality assessment of creatine monohydrate typically uses high-performance liquid chromatography to separate creatine from creatinine and other impurities. Other methods include nuclear magnetic resonance spectroscopy, titration, and infrared spectroscopy for identity confirmation. Purity is often reported as a percentage of the labeled compound on a dry basis, while moisture content is measured separately. Because different analytical methods have different selectivity, comparing purity values across sources requires attention to the method and sample preparation.
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.
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.
Identity and purity are commonly assessed by high-performance liquid chromatography, often with ultraviolet detection, and by spectroscopic techniques such as infrared or nuclear magnetic resonance. These methods can distinguish creatine from creatinine and detect related impurities. Moisture content may be measured by Karl Fischer titration or loss on drying. Particle size, bulk density, and heavy metal limits are additional quality parameters. Not every product is tested by every method, so specifications depend on the intended use and regulatory framework.
G-protein-coupled receptor kinase 7 (EC 2.7.11.14, GRK7, cone opsin kinase, iodopsin kinase) is a serine/threonine-specific protein kinase involved in phototransduction. This enzyme catalyses the phosphorylation of cone (color) photopsins in retinal cones during high acuity color vision primarily in the fovea.
== Risk management and regulations == Aflatoxin B1 exposure is best managed by measures aimed at preventing contamination of crops in the field, post-harvest handling, and storage, or via measures aimed at detecting and decontaminating contaminated commodities or materials used in animal feed. For instance, biological decontamination involving the use of a single bacterial species, Flavobacterium aurantiacum has been used to remove aflatoxin B1 from peanuts and corn. Several countries around the world have rules and regulations governing aflatoxin B1 in foods and these include the maximum permitted, or recommended levels of aflatoxin B1 for certain foods.
=== Bans === In March 2019, as a result of the previously mentioned research, the European Union banned the use of chlorothalonil dated to take effect May 20, 2020. Switzerland followed in December 2019.
The total number of people living in extreme poverty globally decreased by two-thirds from 1990 to 2025 (measured using the international poverty line), with other poverty measurements showing similar trends. However, most people surveyed in several countries incorrectly think it has increased or stayed the same. Although the human population of Earth is increasing, the rate of human population growth is decreasing and the world population is expected to peak and then begin falling during the 21st century. Improvements in agricultural productivity and technology are expected to be able to meet anticipated increased demand for resources, making a global human overpopulation scenario unlikely. For any given production set, there is not a set amount of labor input (a "lump of labor") to produce that output. This fallacy is commonly seen in Luddite and later, related movements as an argument either that automation causes permanent, structural unemployment, or that labor-limiting regulation can decrease unemployment. In fact, changes in capital allocation, efficiency, and economies of learning can change the amount of labor input for a given set of production. Income is not a direct factor in determining credit score in the United States. Rather, credit score is affected by the amount of unused available credit, which is in turn affected by income. Income is also considered when evaluating creditworthiness more generally. The US public vastly overestimates the amount spent on foreign aid.
Sources: en.wikipedia.org
The Xia dynasty was overthrown after the Battle of Mingtiao, around 1600 BCE, by Cheng Tang, who established the Shang dynasty (c. 1600–1046 BCE). The earliest archaeological examples of Chinese writing date back to this period – from characters inscribed on oracle bones used for divination – but the well-developed characters hint at a much earlier origin of writing in China. During the Shang dynasty, people of the Wu area in the Yangtze River Delta were considered a different tribe, and described as being scantily dressed, tattooed and speaking a distinct language. Later, Taibo, elder uncle of Ji Chang – on realising that his younger brother, Jili, was wiser and deserved to inherit the throne – fled to Wu and settled there. Three generations later, King Wu of the Zhou dynasty defeated King Zhou (the last Shang king), and enfeoffed the descendants of Taibo in Wu – mirroring the later history of Nanyue, where a Chinese king and his soldiers ruled a non-Han population and mixed with locals, who were sinicized over time.
Cardiac alpha actin is a 42.0 kDa protein composed of 377 amino acids. Cardiac alpha actin is a filamentous protein extending from a complex mesh with cardiac alpha-actinin (ACTN2) at Z-lines towards the center of the sarcomere. Polymerization of globular actin (G-actin) leads to a structural filament (F-actin) in the form of a two-stranded helix. Each actin can bind to four others. The atomic structure of monomeric actin was solved by Kabsch et al., and closely thereafter this same group published the structure of the actin filament. Actins are highly conserved proteins; the alpha actins are found in muscle tissues and are a major constituent of the contractile apparatus. Cardiac (ACTC1) and skeletal (ACTA1) alpha actins differ by only four amino acids (Asp4Glu, Glu5Asp, Leu301Met, Ser360Thr; cardiac/skeletal). The actin monomer has two asymmetric domains; the larger inner domain comprised by sub-domains 3 and 4, and the smaller outer domain by sub-domains 1 and 2. Both the amino and carboxy-termini lie in sub-domain 1 of the outer domain.
== Company structure == Corporate group, an industrial business group in Western democracies Combine (enterprise), an industrial business group in socialist countries, particularly the former Soviet Union
Proglumide, sold under the brand name Milid, is a drug that inhibits gastrointestinal motility and reduces gastric secretions. It acts as a cholecystokinin antagonist, which blocks both the CCKA and CCKB subtypes. It was used mainly in the treatment of stomach ulcers, although it has now been largely replaced by newer drugs for this application. An interesting side effect of proglumide is that it enhances the analgesia produced by opioid drugs, and can prevent or even reverse the development of tolerance to opioid drugs. This can make it a useful adjuvant treatment to use alongside opioid drugs in the treatment of chronic pain conditions such as cancer, where opioid analgesics may be required for long periods and development of tolerance reduces clinical efficacy of these drugs. Proglumide has also been shown to act as a δ-opioid receptor (DOR) agonist, which may contribute to its analgesic effects. However, other studies show that proglumide has low affinity to the μ-opioid receptor (MOR) and the κ-opioid receptor (KOR) (13% of MOR and 17% of KOR occupancy at 100 μM), but no affinity to DOR. It is questionable whether this is clinically significant, since the concentration they used was very high, and the occupancies were low even at that point. Proglumide also works as a placebo effect amplifier for pain conditions. When injected visibly to a subject, its analgesic effect is bigger than a similarly administered placebo.
Refeeding syndrome (RFS) is a metabolic disturbance which occurs as a result of reinstitution of nutrition in people and animals who are starved, severely malnourished, or metabolically stressed because of severe illness. When too much food or liquid nutrition supplement is eaten during the initial four to seven days following a malnutrition event, the production of glycogen, fat and protein in cells may cause low serum concentrations of potassium, magnesium and phosphate. The electrolyte imbalance may cause neurologic, pulmonary, cardiac, neuromuscular, and hematologic symptoms—many of which, if severe enough, may result in death. Refeeding syndrome can occur when someone who has not eaten for a long time, starts eating normal or even binging amounts of food. Individuals with drug abuse who begin to reintroduce normal eating habits after a period of malnutrition may be at increased risk for refeeding syndrome.
Sources: en.wikipedia.org
== Uses == P. rubens is the source of β-lactam antibiotics, principally of penicillins and to a lesser extent, cephalosporins. The species produces three penicillins, benzylpenicillin (G), phenoxymethylpenicillin (V) and octanoylpenicillin (K). Penicillin G is a naturally occurring compound that was first isolated and used as an antibiotic. Penicillins from P. rubens are effective against Gram-positive bacteria such as the species of Bacillus, Clostridium, Corynebacterium, Pneumococcus, Streptococcus, and Staphylococcus. They are clinically used to treat actinomycosis, anthrax, botulism, clostridial infections, diphtheria, empyema, endocarditis, food poisoning (due to Listeria), gas gangrene, meningitis, pneumonia, pericarditis, septicaemia, and syphilis. However, they are useless against Gram-negative bacteria since these bacteria are impermeable to the compounds because of their additional outer cell membrane, as well as some species producing pencillases (β-lactamases) that destroy the penicillin structure (β-lactam ring). However, semisynthetic penicillins like aminopenicillins (ampicillin, amoxicillin, and bacampicillin), carboxypenicillins (carbenicillin and ticarcillin) and ureidopenicillins (mezlocillin, azlocillin, and piperacillin) have been developed that are effective against these bacteria. Cephalosporins, naturally produced by other fungi belonging to the genus Acremonium, are one of the most widely used antibiotics by clinicians and is also produced by P. rubens. However, they are not naturally produced by P. rubens.
The AAS that have been used most commonly in medicine are testosterone and its many esters (but most typically testosterone undecanoate, testosterone enanthate, testosterone cypionate, and testosterone propionate), nandrolone esters (typically nandrolone decanoate and nandrolone phenylpropionate), stanozolol, and metandienone (methandrostenolone). Others that have also been available and used commonly but to a lesser extent include methyltestosterone, oxandrolone, mesterolone, and oxymetholone, as well as drostanolone propionate (dromostanolone propionate), metenolone (methylandrostenolone) esters (specifically metenolone acetate and metenolone enanthate), and fluoxymesterone. Dihydrotestosterone (DHT), known as androstanolone or stanolone when used medically, and its esters are also notable, although they are not widely used in medicine. Boldenone undecylenate and trenbolone acetate are used in veterinary medicine. Designer steroids are AAS that have not been approved and marketed for medical use but have been distributed through the black market. Examples of notable designer steroids include 1-testosterone (dihydroboldenone), methasterone, trenbolone enanthate, desoxymethyltestosterone, tetrahydrogestrinone, and methylstenbolone.
==== Fishkeeping ==== Hydrogen peroxide is used in aquaculture for controlling mortality caused by various microbes. In 2019, the U.S. FDA approved it for control of Saprolegniasis in all coldwater finfish and all fingerling and adult coolwater and warmwater finfish, for control of external columnaris disease in warm-water finfish, and for control of Gyrodactylus spp. in freshwater-reared salmonids. It can also be used to increase the oxygen content of water to enable fish to survive otherwise-hypoxic conditions. The hydrogen peroxide releases oxygen by decomposition when it is exposed to catalysts such as manganese dioxide. Sodium percarbonate, a complex containing hydrogen peroxide as its active agent, is sold for oxygenation in acutely oxygen-deficient water to enable fish survival.
North Korea's government is totalitarian and maintains strict control over the country and its society, which experts anticipated could help in enforcing disease control measures such as social distancing. The country has a high number of doctors for its per capita GDP, though they are less skilled and equipped than their counterparts in the Western world and in South Korea. North Korea also has a "somewhat better standard of sanitation" than other countries of the same economic level (e.g. Botswana or Laos).
Sources: en.wikipedia.org
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.
Creatinine forms through irreversible cyclization and loss of water from creatine, and the rate increases with temperature, moisture, and pH changes. In dry solid form, the reaction is slow. In solution, degradation can become noticeable over time.
A specification typically lists assay range, water content, appearance, identification, and limits for heavy metals, residual solvents, and microbial counts. It may also include particle size distribution or bulk density for handling purposes. These parameters are distinct from any claimed performance effect.
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.