Everything below concerns HPLC. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-02-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | 15–25 °C | Cool, dry, sealed conditions slow conversion to creatinine. |
| Moisture sensitivity | Moderate | Absorbs water from humid air, which can cause caking. |
| Primary purity method | HPLC-UV | Separates creatine from creatinine and related impurities. |
| Moisture method | Karl Fischer titration | Measures water content; loss on drying is an alternative. |
| Degradation product | Creatinine | Forms by dehydration, especially in solution or humid heat. |
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.
Analytical methods for creatine monohydrate focus on identity, purity, and degradation products. High-performance liquid chromatography with ultraviolet detection is common, often at a wavelength near 210 nanometers. Titration and nuclear magnetic resonance spectroscopy can also quantify the parent compound. Pharmacopeial monographs specify tests for appearance, solubility, water content, and related substances, including creatinine. Purity values above 99 percent are typical for pharmaceutical-grade material, though supplement-grade products vary. Independent verification can detect label discrepancies.
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.
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.
== Side effects == The most common adverse effects in studies were upper respiratory tract infection, headache, nausea, and diarrhea. The most common side effects in clinical trials were nasopharyngitis, nausea, headaches, herpes simplex (including oral herpes, ophthalmic herpes, herpes dermatitis and genital herpes), and increase in blood creatine phosphokinase. Abrocitinib can cause serious infections, malignancy, major cardiac events, thrombosis and other laboratory abnormalities including thrombocytopenia, lymphopenia, and lipid elevations. However, according to clinical data, Abrocitinib is well tolerated. The total adverse reactions were not statistically different between the placebo and the dose of 100 mg of abrocitinib. However, it was slightly higher for the dose of 200 mg of abrocitinib. Symptoms such as acne, headache, and nausea, appeared in the first two weeks of starting abrocitinib, and it was not necessary to interrupt the treatment. In general, the AE frequency of abrocitinib was the same or a little bit higher than in case of placebo or dupilumab.
Some patients report complete resolution of symptoms when the implants are removed without replacement". A 2021 study by Cleveland Clinic physicians investigated the outcome of breast implant removal on women with breast implants who had reported difficulty breathing or tightness in their chest; this is one of the symptoms associated with breast implant illness. The study examined breast implant patients who reported problems breathing, comparing their scores on 6 pulmonary function tests before and after their implants and scar capsules were removed. The researchers reported that 74% of the patients reported significant improvements on at least 3 of the pulmonary function tests. In self-reports, all study participants reported that their breathing improved after their implant surgery.
Mark Cassell, How Governments Privatize: the Politics of Divestment in the United States and Germany, Georgetown University Press, 2002. Vladimiro Giacché, Anschluss: Die deutsche Vereinigung und die Zukunft Europas, Laika-Verlag, Hamburg 2014, German Edition, ISBN 978-3-9442-3326-0.
Channel-switching is the action of consumers switching from one type of channel intermediary to a different type of intermediary for their purchases. Examples include switching from brick-and-mortar stores to online catalogues and e-commerce providers; switching from grocery stores to convenience stores or switching from top tier department stores to mass market discount outlets. A number of factors have led to an increase in channel switching behaviour; the growth of e-commerce, the globalization of markets, the advent of category killers (such as Officeworks and Kids 'R Us) as well as changes in the legal or statutory environment. For instance, in Australia and New Zealand, following a relaxation of laws prohibiting supermarkets from selling therapeutic goods, consumers have gradually switched away from pharmacies and toward supermarkets for the purchase of minor analgesics, cough and cold preparations and complementary medicines such as vitamins and herbal remedies. For the consumer, channel switching offers a more diverse shopping experience, which may concern some sellers by its potential to erode market share. Evidence of channel switching can suggest that disruptive forces are at play, and that consumer behaviour is undergoing fundamental changes. A consumer may be prompted to switch channels when the product or service can be found at cheaper prices, when superior models become available, when a wider range is offered, or simply because it is more convenient to shop through a different channel (e.g. online or one-stop shopping).
== Mathematics and logic == Contraction (operator theory), in operator theory, state of a bounded operator between normed vector spaces after suitable scaling Contraction hierarchies, in applied mathematics, a technique to speed up shortest-path routing Contraction mapping, a type of function on a metric space Edge contraction or vertex contraction, graph operations used in graph theory Tensor contraction, an operation on one or more tensors that arises from the natural pairing of a finite-dimensional vector space and its dual Interior product, a tensor contraction specifically of a differential form with a vector field Left contraction and right contraction of multivectors in a geometric algebra, extensions of the inner product One of the rules of conditional independence, in probability Contraction (logic), a structural rule in proof theory
Sources: en.wikipedia.org
=== Pharmacokinetics === The elimination half-lives of clinically used orexin receptor antagonists are 12 hours for suvorexant, about 17 to 19 hours ("effective" half-life) or 55 hours (terminal elimination half-life) for lemborexant, and 6 to 10 hours for daridorexant. The elimination half-lives of investigational orexin receptor antagonists are 2 to 3 hours for seltorexant and about 1.5 to 3 hours for vornorexant. The pharmacokinetics of suvorexant are significantly affected by age, sex, and other factors, leading to increased blood concentrations in female, obese, and older patients. These factors do not significantly affect the pharmacokinetics of lemborexant or daridorexant. All three marketed orexin antagonists do not need to be dose adjusted in patients with reduced renal function, as the pharmacokinetic profiles of these medications are not significantly affected. In patients with moderate to severe hepatic impairment, dose adjustments of these medications may be necessary.
== Medical uses == Relugolix is approved in the United States, Canada and the United Kingdom for the treatment of prostate cancer, in Japan for the treatment of uterine fibroids (uterine leiomyoma) and in the United Kingdom for endometriosis.
== Honors == Foreign Honorary Member of the American Academy of Arts and Sciences (1832) The Moon crater Legendre is named after him. Main-belt asteroid 26950 Legendre is named after him. Legendre is one of the 72 prominent French scientists who were commemorated on plaques at the first stage of the Eiffel Tower when it first opened. A street in Paris' 17th Arrondissement is named after him.
=== Haematoxylin === Haematoxylin (hematoxylin in North America) is a nuclear stain. Used with a mordant, haematoxylin stains nuclei blue-violet or brown. It is most often used with eosin in the H&E stain (haematoxylin and eosin) staining, one of the most common procedures in histology.
=== Polymers === Already the first work on vinylene carbonate describes its bulk polymerization a colorless polymer, which hydrolyzes to a water-soluble product. Subsequent publications suggest that the first authors produced only low molecular weight oligomers. The preparation of higher molecular weight polymers with useful properties depends critically on the purity of the vinylene carbonate monomer. Vinylene carbonate can be homopolymerized in bulk, in solution, in suspension and in dispersion using radical initiators such as azobis(isobutyronitrile) (AIBN) or benzoyl peroxide. It can also be copolymerized with other vinyl monomers such as vinyl pyrrolidone or vinyl propionate.
Sources: en.wikipedia.org
=== Sports journalists === Jeremy Gaige (1951), chess archivist and journalist Paul Zimmerman (1955), football writer for Sports Illustrated known as "Dr. Z" Robert Lipsyte (1957), sports writer for The New York Times, correspondent for ABC News and host of The Eleventh Hour Chet Forte (1957), first director of Monday Night Football Steven Krasner (1975), sports journalist famous for covering the Boston Red Sox for The Providence Journal 1986–2008 Bob Klapisch (1979), sports writer for The Record and Fox Sports Gary Cohen (1981), television play-by-play announcer for the New York Mets
== History == From the Classical Period to the Medieval Period, the body and the soul were believed to be intimately connected, based on several theories put forth by the philosopher Plato. Wounds on the body were believed to correlate with wounds to the soul and vice versa; wounds were seen as an outward sign of an inward illness. Thus, a man who was wounded physically in a serious way was said to be hindered not only physically but spiritually as well. If the soul was wounded, that wound may also eventually become physically manifest, revealing the true state of the soul. Wounds were also seen as writing on the "tablet" of the body. Wounds acquired in war, for example, told the story of a soldier in a form which all could see and understand, and the wounds of a martyr told the story of their faith.
=== Facilities at CIRB === Facilities include 20 research laboratories, livestock, frozen semen library, air-conditioned, 125-seat audio-visual seminar hall, guest house with accommodations for 25 guests. The main campus is at Hisar, with a satellite campus at Nabha in Punjab, and two regional stations in Andhra Pradesh and Gujarat respectively.
=== Production and fermentation === First, raw milk (either from cattle, goats or sheep) is mixed and pasteurized at 72 °C (162 °F) for 15 seconds. Then, acidification occurs: a starter culture, such as Streptococcus lactis, is added in order to change lactose to lactic acid, thus changing the acidity of the milk and turning it from liquid to solid. The next step is coagulation, where rennet, a mixture of rennin and other materials found in the stomach lining of a calf is added to solidify the milk further. Following this, thick curds are cut typically with a knife to encourage the release of liquid or whey. The smaller the curds are cut, the thicker and harder the resulting cheese will become. After the curds have been ladled into containers in order to be drained and formed into a full wheel of cheese, the Penicillium roqueforti inoculum is sprinkled on top of the curds along with Brevibacterium linens. Then, the curd granules are knit in molds to form cheese loaves with a relatively open texture. Next, whey drainage continues for 10–48 hours in which no pressure is applied, but the molds are inverted frequently to promote this process. Salt is then added to provide flavor as well as to act as a preservative so the cheese does not spoil through the process of brine salting or dry salting for 24–48 hours. The final step is ripening the cheese by aging it. When the cheese is freshly made, there is little to no blue cheese flavor development. Usually, a fermentation period of 60–90 days is needed before the flavor of the cheese is typical and acceptable for marketing.
Wilmer David "Vinegar Bend" Mizell Sr. (August 13, 1930 – February 21, 1999) was an American baseball player and politician. From 1952 to 1962, he was a left-handed pitcher for the St. Louis Cardinals, Pittsburgh Pirates and New York Mets of Major League Baseball. Six years after retiring, he was elected to the United States House of Representatives from North Carolina's 5th congressional district. He served three terms as a Republican from 1969 to 1975. Mizell was born in Leakesville, Mississippi, but started playing baseball in nearby Vinegar Bend, Alabama, the town from which he drew his nickname. Signed by the Cardinals in 1949, he debuted with them in 1952, ranking among the Top 10 in the National League (NL) in strikeouts for two years before spending 1954 and 1955 in military service. He returned to the Cardinals in 1956 and was named to two Major League Baseball All-Star Games in 1959, but St. Louis felt like he never attained his full potential. They traded him to Pittsburgh early in the 1960 season, and Mizell led the NL in winning percentage (.636) as the Pirates defeated the New York Yankees in the 1960 World Series. He remained with the Pirates until early in the 1962 season, last pitching in the major leagues with the Mets. While pitching for the Winston-Salem Cardinals in 1951, Mizell had settled in Midway, North Carolina. Six years after he threw his last major league pitch, he was elected to the House of Representatives, serving North Carolina's newly aligned 5th district.
Sources: en.wikipedia.org
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.
Purity is typically evaluated by chromatographic separation with ultraviolet detection, sometimes supported by spectroscopic identity tests. Moisture and creatinine content are common quality parameters. Results depend on the analytical method, sample preparation, and specification limits.
Clumping occurs when powder absorbs moisture, causing particles to stick together. Humidity, temperature changes, and repeated container opening promote this effect. Clumps do not necessarily indicate chemical degradation, but they can affect weighing and mixing.
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.