Everything below concerns Karl Fischer titration. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-02-03. Numbers and descriptions here follow the published literature rather than marketing material.
Analytical laboratories commonly use high-performance liquid chromatography to separate creatine from creatinine and related impurities. Ion chromatography, nuclear magnetic resonance, and titration assays can also quantify the compound. Water content is measured by Karl Fischer titration or loss on drying, because the monohydrate has a defined theoretical water fraction. Particle size, bulk density, and flowability are physical properties that affect blending and capsule filling. These measurements support quality control and help verify that a lot matches its specification.
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.
Commercial creatine monohydrate is produced mainly by chemical synthesis rather than extraction from animal tissue. Suppliers provide a certificate of analysis listing assay, water content, and impurity limits, and some products undergo third-party testing. Verification of identity can use infrared or Raman spectroscopy alongside chromatographic methods. Storage recommendations generally call for a cool, dry place and a tightly closed container to limit moisture uptake. Open questions include how packaging, flavoring agents, and long-term storage affect the stability of finished products.
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.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | 15-25 °C | Sealed container; protect from moisture and direct heat. |
| Theoretical water content | About 12.1% | One water molecule per creatine molecule. |
| Primary degradation product | Creatinine | Formed by cyclization, especially in aqueous solution. |
| Common analytical method | HPLC-UV | Used to separate creatine from creatinine and related impurities. |
| Regulatory classification (U.S.) | Dietary supplement ingredient | Other jurisdictions may classify it as a food supplement or novel food depending on rules. |
In the human body, creatine is synthesized mainly in the liver and kidneys from the amino acids glycine, arginine, and methionine. Dietary sources include meat, fish, and other animal tissues, which supply preformed creatine. Because plant foods contain little or no creatine, dietary intake varies widely among populations. The compound is stored largely in skeletal muscle, where it is converted to phosphocreatine and used to regenerate adenosine triphosphate during short bursts of activity.
Creatine monohydrate is one of several solid forms of creatine described in the literature. Other forms include anhydrous creatine, creatine hydrochloride, and creatine ethyl ester, each with different solubility and stability characteristics. The monohydrate is distinct from creatinine, a spontaneous breakdown compound that forms when creatine loses water and cyclizes. Commercial descriptions sometimes use synonyms such as methylguanidoacetic acid or N-(aminoiminomethyl)-N-methylglycine, which refer to the same base molecule. These names appear in chemical databases and product labels.
Commercial creatine products appear in several forms, including monohydrate, hydrochloride, citrate, nitrate, and ethyl ester. Creatine monohydrate is the most studied form and serves as a reference material in comparative research. Different forms vary in solubility, pH, and water content, but they share creatine as the active moiety after dissolution. Claims that one form is uniformly superior remain debated, and study designs often differ in population, exercise protocol, and outcome measures. Purity and hydration state are central to interpreting product labels.
Creatine monohydrate is the hydrated form of creatine, a nitrogen-containing organic acid involved in cellular energy transfer. Its molecular formula is C4H11N3O3, and it consists of creatine plus one water molecule in the crystal lattice. The anhydrous base, creatine, has the formula C4H9N3O2. The compound appears as a white, odorless, crystalline powder and is classified as a guanidine derivative. It is distinct from creatinine, a breakdown product measured in clinical chemistry.
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.
Some have argued that there is little evidence to indicate any benefit to using bodybuilding protein or amino acid supplements. A 2005 overview concluded that "[i]n view of the lack of compelling evidence to the contrary, no additional dietary protein is suggested for healthy adults undertaking resistance or endurance exercise". In contrast, a 2018 systematic review, meta-analysis and meta-regression concluded that, “Dietary protein supplementation significantly enhanced changes in muscle strength and size during prolonged RET in healthy adults.“ (RET is an abbreviation for resistance exercise training.) Instant breakfast Protein bar "Dietary Supplement Health and Education Act of 1994". U.S. Food and Drug Administration. 4 February 2020. Archived from the original on June 2, 2009.
Many pathways and signals lead to apoptosis, but these converge on a single mechanism that actually causes the death of the cell. After a cell receives stimulus, it undergoes organized degradation of cellular organelles by activated proteolytic caspases. In addition to the destruction of cellular organelles, mRNA is rapidly and globally degraded by a mechanism that is not yet fully characterized. mRNA decay is triggered very early in apoptosis. A cell undergoing apoptosis shows a series of characteristic morphological changes. Early alterations include:
Azurin is a small, periplasmic, bacterial blue copper protein found in Pseudomonas, Bordetella, or Alcaligenes bacteria. Azurin moderates single-electron transfer between enzymes associated with the cytochrome chain by undergoing oxidation-reduction between Cu(I) and Cu(II). Each monomer of an azurin tetramer has a molecular weight of approximately 14kDa, contains a single copper atom, is intensively blue, and has a fluorescence emission band centered at 308 nm. Azurins and pseudoazurins participate in the denitrification processes in bacteria., including the gram-negative bacteria Pseudomonas aeruginosa, by interacting with cytochrome c551. Azurin from P aeruginosa is a type I blue copper protein (cupredoxin), while cytochrome c551 (9 kDa) is a haem-containing cytochrome. Azurin possesses a relatively large hydrophobic patch close to the active site, and two residues in this hydrophobic patch, Met-44 and Met-64, are believed to be involved in its interaction with the redox partners cytochrome c551 and nitrite reductase. Although unrelated to its electron-transfer property, azurin has been found to have anticancer properties through its interaction with tumor-suppressor protein p53.
Enzyme specificity refers to the interactions between any particular enzyme and its corresponding substrate. In addition to the specificity in binding its substrates, correct proximity and orientation as well as binding the transition state provide an additional layer of enzyme specificity. Enzymes vary in the specificity of the substrates that they bind to, in order to carry out specific physiological functions. Some enzymes may need to be less specific and therefore may bind to numerous substrates to catalyze a reaction. On the other hand, certain physiological functions require extreme specificity of the enzyme for a single specific substrate in order for a proper reaction and physiological phenotype to occur. The different types of categorizations differ based on their specificity for substrates. Most generally, they are divided into four groups: absolute, group, linkage, and stereochemical specificity.
The LCPO method uses a linear approximation of the two-body problem for a quicker analytical calculation of ASA. The approximations used in LCPO result in an error in the range of 1-3 Ų. In 2011, a method was presented that calculates ASA fast and analytically using a power diagram. Accessible surface area is often used when calculating the transfer free energy required to move a biomolecule from an aqueous solvent to a non-polar solvent, such as a lipid environment. The LCPO method is also used when calculating implicit solvent effects in the molecular dynamics software package AMBER. It is recently suggested that (predicted) accessible surface area can be used to improve prediction of protein secondary structure.
Sources: en.wikipedia.org
Volanesorsen was approved by the European Medicines Agency (EMA) for the treatment of familial chylomicronaemia syndrome in May 2019. In January 2013 mipomersen (marketed as Kynamro) was approved by the FDA for the treatment of homozygous familial hypercholesterolemia. Inotersen received FDA approval for the treatment of hereditary transthyretin-mediated amyloidosis in October 2018. The application for inotersen was granted orphan drug designation. It was developed by Ionis Pharmaceuticals and licensed to Akcea Therapeutics. Patisiran (sold under Onpattro) was developed by Alnylam Pharmaceuticals, and also approved for use in the US and EU in 2018 with orphan drug designation. Its mechanism-of-action is the active substance of small interfering RNA (siRNA), which allows it to interfere with and block the production of transthyretin. As such, it was the first FDA-approved siRNA therapeutic.
Pandey has the Human Proteome Organization(HUPO)'s Discovery in Proteomic Sciences Award. The Wellcome Trust/DBT India Alliance named him a Margdarshi Fellow, and he established a Center for Molecular Medicine at NIMHANS in Bangalore as a result. He is an Associate Editor of Clinical Proteomics and a member of the Editorial Boards of Molecular and Cellular Proteomics, Proteomics, and the Journal of Clinical Investigation. He has received the Howard Temin Award from the National Cancer Institute, the Experimental Pathologist-In-Training Award from the American Society for Investigative Pathology, and the Sidney Kimmel Scholar Award from the Sidney Kimmel Foundation for Cancer Research. The United States Department of Defense also bestowed upon him the Era of Hope Scholar Award.
The full-length human protein comprises 2,843 amino acids with a (predicted) molecular mass of 311646 Da. Several N-terminal domains have been structurally elucidated in unique atomistic high-resolution complex structures. Most of the protein is predicted to be intrinsically disordered. It is not known if this large predicted unstructured region from amino acid 800 to 2843 persists in vivo or would form stabilised complexes – possibly with yet unidentified interacting proteins. Recently, it has been experimentally confirmed that the mutation cluster region around the center of APC is intrinsically disordered in vitro.
Eculizumab (Soliris) appears to be useful for atypical hemolytic uremic syndrome (aHUS). In September 2011 the U.S. Food and Drug Administration (FDA) approved it as an orphan drug to treat people with aHUS. This approval was based on two small prospective trials of 17 people and 20 people. In the UK, NICE issued guidance on the use of Eculizumab for treating aHUS, based on five evidence sources, including those used by the FDA No randomised controlled trials were identified. All prospective studies were phase 2, open‑label, non‑randomised, single‑arm studies that included patients with different clinical baseline characteristics. The prospective studies lasted 26 weeks; however, patients were allowed to continue treatment with eculizumab in a long‑term extension study. Ravulizumab-cwvz (Ultomiris) is a second generation monoclonal antibody for aHUS made by Alexion pharmaceuticals, Inc. The target of ravulizumab-cwvz is the same eculizumab (Soliris) with changes to the structure of the antibody resulting in a longer serum half life and therefore reduced dosing regimen.
Sources: en.wikipedia.org
Enzymes incur catalysis by binding more strongly to transition states than substrates and products. At the catalytic binding site, several different interactions may act upon the substrate. These range from electric catalysis, acid and base catalysis, covalent catalysis, and metal ion catalysis. These interactions decrease the activation energy of a chemical reaction by providing favorable interactions to stabilize the high energy molecule. Enzyme binding allows for closer proximity and exclusion of substances irrelevant to the reaction. Side reactions are also discouraged by this specific binding. Types of enzymes that can perform these actions include oxidoreductases, transferases, hydrolases, lyases, isomerases, and ligases. For instance, the transferase hexokinase catalyzes the phosphorylation of glucose to make glucose-6-phosphate. Active site residues of hexokinase allow for stabilization of the glucose molecule in the active site and spur the onset of an alternative pathway of favorable interactions, decreasing the activation energy.
ABC transporters utilize the energy of ATP binding and hydrolysis to transport various substrates across cellular membranes. They are divided into three main functional categories. In prokaryotes, importers mediate the uptake of nutrients into the cell. The substrates that can be transported include ions, amino acids, peptides, sugars, and other molecules that are mostly hydrophilic. The membrane-spanning region of the ABC transporter protects hydrophilic substrates from the lipids of the membrane bilayer thus providing a pathway across the cell membrane. Eukaryotes do not possess any importers. Exporters or effluxers, which are present both in prokaryotes and eukaryotes, function as pumps that extrude toxins and drugs out of the cell. In gram-negative bacteria, exporters transport lipids and some polysaccharides from the cytoplasm to the periplasm. The third subgroup of ABC proteins do not function as transporters, but are rather involved in translation and DNA repair processes.
Many pathways and signals lead to apoptosis, but these converge on a single mechanism that actually causes the death of the cell. After a cell receives stimulus, it undergoes organized degradation of cellular organelles by activated proteolytic caspases. In addition to the destruction of cellular organelles, mRNA is rapidly and globally degraded by a mechanism that is not yet fully characterized. mRNA decay is triggered very early in apoptosis. A cell undergoing apoptosis shows a series of characteristic morphological changes. Early alterations include:
an intermediate or building block in the synthesis of non-ionic and other surfactants and related functional additives; a component of lubricant and plastic additive systems, including thermoplastic polyurethanes, where long-chain alcohols are used to modify flexibility and permeability; a minor constituent of policosanol-type mixtures employed in cosmetics and personal-care products as part of the lipid phase of creams and emulsions. Because of its chain length and structural similarity to other fatty alcohols, 1-heneicosanol is also used as a reference compound and analytical standard in studies of plant waxes, policosanol mixtures and related lipid fractions. Available safety data sheets describe 1-heneicosanol as a low-volatility solid that is not classified as hazardous under European CLP regulations, but which may cause mild irritation to the skin, eyes and respiratory tract on contact or inhalation of dust. Standard laboratory precautions such as avoiding dust formation, using local exhaust ventilation and wearing eye and skin protection are recommended.
Aldo Carl Leopold (December 18, 1919 – November 18, 2009) was an American academic and plant physiologist, son of Aldo Leopold, a noted ecologist. He is known for his research on soybeans which led to techniques allowing insulin to be dried and later processed into an inhalable insulin. Aldo Carl Leopold was born to Aldo Leopold, a noted ecologist and employee of the United States Forest Service, and Estella Leopold in Albuquerque, New Mexico as the 4th of 5 children.
Sources: en.wikipedia.org
A sealed container at room temperature, away from moisture and direct heat, is suitable for most solid material. Keeping the lid closed limits water uptake and caking. Long-term storage in a refrigerator is not necessary if the powder remains dry.
Heat, moisture, and prolonged time in solution promote conversion to creatinine. The reaction is faster at higher temperatures and at pH values far from neutral. Dry powder is much more stable than dissolved material.
Common methods include high-performance liquid chromatography for creatine and creatinine, plus water-content analysis by Karl Fischer titration. Heavy metals, residual solvents, and microbial limits may also be tested. A specification may list total creatine content and impurity limits.
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.