creatine comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-04-20. 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.
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 | 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. |
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.
Commercial creatine monohydrate is typically a white to off-white powder with low odor. It is commonly sold as a fine powder, micronized powder, or larger crystals, but these are physical forms of the same chemical. Purity grades vary, and products may contain small amounts of related substances such as creatinine, dicyandiamide, or moisture. The monohydrate is often selected for supplements and research because its production is well established and its behavior in water is predictable. Analytical certificates usually report assay, loss on drying, and heavy metals.
Creatine monohydrate is a crystalline compound formed from creatine and one water molecule in its solid lattice. Creatine itself is a nitrogen-containing organic acid involved in energy transfer in muscle and other tissues. The monohydrate form is the most common solid form used in research and commercial products because it is stable and easy to handle. The term "monohydrate" refers to the fixed one-to-one ratio of water to creatine in the crystal, not to moisture content. This distinction matters when comparing labels or calculating creatine content.
In aqueous solution, creatine monohydrate exists mainly as a zwitterion, carrying both a positive guanidinium charge and a negative carboxylate charge. This charge separation raises water solubility relative to many neutral organic solids and helps explain its behavior in analytical separations. The monohydrate can lose its water of crystallization under sustained heat or low humidity, converting toward anhydrous creatine. Such transitions matter for mass balance calculations because the hydrate contributes water mass that is not part of the active creatine molecule.
The term creatine monohydrate is often shortened to creatine in casual usage, though other creatine forms exist, including citrate, nitrate, and hydrochloride salts. These alternative forms differ in solubility, pH behavior, and the amount of creatine delivered per unit mass. Regulatory categories vary by country: some jurisdictions treat it as a food ingredient, while others place it under supplement or drug frameworks depending on claims and presentation. Standard reference texts list it as a naturally occurring nitrogenous organic acid rather than a vitamin or mineral.
The 1-deoxysphingolipids (1-deoxySLs) are a recently identified class of atypical sphingolipids (SLs). They are produced via a non-canonical biosynthetic pathway, and their defining feature, the absence of a C1 hydroxyl group (C1-OH), prevents their further conversion into complex sphingolipids. Under normal conditions, sphingolipids are synthesized through a reaction catalyzed by the enzyme serine-palmitoyltransferase (SPT), which condenses serine with palmitoyl-CoA. However, when SPT utilizes alternative amino acid substrates such as alanine or glycine instead of serine, it leads to the formation of 1-deoxySLs. Unlike canonical sphingolipids, 1-deoxysphingolipids cannot be degraded via standard catabolic pathways. As a result, they accumulate to high levels and have been implicated in a range of neurological and metabolic disorders. There are two types of 1-deoxySLs: 1-deoxysphinganine and 1-deoxymethylsphinganine.
While it is usually considered that the driver has the responsibility when collisions occur, vehicle can also contribute to collisions, up to 3% to 5% of crashes. Two kinds of programs exist: new car assessment program for new cars, and vehicle inspections for other ones. A New Car Assessment Program is a government or institutional car safety program tasked with evaluating new car designs for performance against various safety threats. Two well known NCAP are United States New Car Assessment Program since 1978 and European New Car Assessment Programme since 1997.
Within the field of molecular biology, a protein-fragment complementation assay, or PCA, is a method for the identification and quantification of protein–protein interactions. In the PCA, the proteins of interest ("bait" and "prey") are each covalently linked to fragments of a third protein (e.g. DHFR, which acts as a "reporter"). Interaction between the bait and the prey proteins brings the fragments of the reporter protein in close proximity to allow them to form a functional reporter protein whose activity can be measured. This principle can be applied to many different reporter proteins and is also the basis for the yeast two-hybrid system, an archetypical PCA assay.
Aspartate transaminase, as with all transaminases, operates via dual substrate recognition; that is, it is able to recognize and selectively bind two amino acids (Asp and Glu) with different side-chains. In either case, the transaminase reaction consists of two similar half-reactions that constitute what is referred to as a ping-pong mechanism. In the first half-reaction, amino acid 1 (e.g., L-Asp) reacts with the enzyme-PLP complex to generate ketoacid 1 (oxaloacetate) and the modified enzyme-PMP. In the second half-reaction, ketoacid 2 (α-ketoglutarate) reacts with enzyme-PMP to produce amino acid 2 (L-Glu), regenerating the original enzyme-PLP in the process. Formation of a racemic product (D-Glu) is very rare. The specific steps for the half-reaction of enzyme-PLP + aspartate ⇌ {\displaystyle \rightleftharpoons } enzyme-PMP + oxaloacetate are as follows (see figure); the other half-reaction (not shown) proceeds in the reverse manner, with α-ketoglutarate as the substrate.
Haplotype refers to a group of genetic variants inherited together on a chromosome from one parent due to their genetic linkage. Haplotype phasing (also called haplotype estimation) refers to the process of reconstructing individual haplotypes, important for determining the genetic basis of diseases. Linked-read sequencing allows consistent coverage of genes related to different diseases, helping scientists to obtain all the regions carrying mutations from targeted genes. For example, in 2018, a group of researchers used linked-read sequencing technology to sequence genetic information from a pregnant woman who was a carrier of Duchenne muscular dystrophy (DMD) mutation. Linked-read sequencing allows them to identify the maternal haplotypes and determine the presence of the mutant alleles in the foetal DNA. This non-invasive prenatal diagnosis of DMD demonstrates the clinical applicability of linked-read sequencing.
Sources: en.wikipedia.org
Although hydroperoxide often refers to a class of organic compounds, many inorganic or metallo-organic compounds are hydroperoxides. One example involves sodium perborate, a commercially important bleaching agent with the formula Na2[(HO)2B]2(OO)2)]. It acts by hydrolysis to give a boron-hydroperoxide: [(HO)2B]2(OO)2)2− + 2 H2O ⇌ 2 [(HO)3B(OOH)]− This hydrogen peroxide then releases hydrogen peroxide: [(HO)3B(OOH)]− + H2O ⇌ B(OH)−4 + H2O2 Several metal hydroperoxide complexes have been characterized by X-ray crystallography, for example: triphenylsilicon and triphenylgermanium hydroperoxides can be obtained by reaction of initial chlorides with excess of hydrogen peroxide in presence of base. Some form by the reaction of metal hydrides with oxygen gas: LnM−H + O2 → LnM−O−O−H (Ln refers to other ligands bound to the metal) Some transition metal dioxygen complexes abstract H atoms (and sometimes protons) to give hydroperoxides: LnM(O2) + H → LnMOOH
SPATT was introduced in 2004 as a method of monitoring aquatic toxins. This tool is able to adsorb toxins generated by microalgae or cyanobacteria, known as cyanotoxins. The adsorption is passive, and the biotoxins adhere to porous, resin filled sachets, or SPATT bags where they are then physically removed and examined. SPATT is a useful tool in tracking algal blooms as it is reliable, sensitive, and inexpensive. It has the ability to quickly alert the existence of aquatic toxins which prevents it from bioaccumulating in marine life. One of the downsides is that it does not give very good results for water-soluble toxins as compared to hydrophobic compounds. This tool is mainly used to determine intercellular concentrations of toxins but the cyanobacteria can also be lysed to determine the total toxin amount in a sample. Other drawbacks, such as a lack in calibration and the ability to only monitor dissolved toxins, make it difficult for this tool to be implemented in a more widespread manner. However, SPATT devices are able to detect many lipophilic and hydrophilic toxins that are linked to harmful algal bloom.
58. Dermatol Online J. 2018 May 15;24(5):13030/qt2gz9f9jk. A glimpse into the underground market of melanotan. Callaghan Iii DJ(1). Author information: (1)Department of Dermatology, Boston Medical Center, Boston, Massachusetts. danieljcallaghan3@gmail.com. Melanotan-I and melanotan-II are alpha-melanocyte stimulating hormone (a-MSH) analogues that can be purchased illicitly online with relative ease and are injected subcutaneously to stimulate a tan. Little is known about the use of these unregulated substances. An observational survey was posted to an online forum in which participants share their experiences using melanotan-I or melanotan-II. Users were asked to complete this voluntary, anonymous survey, which had questions focusing on motivation and hesitation for and against using melanotan, difficulty in acquiring it, and plans for continuing to use melanotan in the future.
A/B tests are sensitive to variance; they require a large sample size in order to reduce standard error and produce a statistically significant result. In applications in which active users are abundant, such as with popular online social-media platforms, obtaining a large sample size is trivial. In other cases, large sample sizes are obtained by increasing the experiment enrollment period. However, using a technique coined by Microsoft as Controlled Experiment Using Pre-Experiment Data (CUPED), variance from before the experiment start can be taken into account so that fewer samples are required to produce a statistically significant result. Because of its nature as an experiment, running an A/B test introduces the risk of wasted time and resources if the test produces unwanted or unhelpful results. In December 2018, representatives with experience in large-scale A/B testing from 13 organizations (Airbnb, Amazon, Booking.com, Facebook, Google, LinkedIn, Lyft, Microsoft, Netflix, Twitter, Uber and Stanford University) summarized the top challenges in a paper. The challenges were grouped into four areas: analysis, engineering and culture, deviations from traditional A/B tests and data quality.
Sources: en.wikipedia.org
Most atomic nuclei contain protons and neutrons. The number of protons determines the chemical element the nucleus belongs to. Different isotopes of the same element have different numbers of neutrons in their nuclei, but contain the same number of protons. For example, isotopes of carbon include carbon-12, carbon-13, carbon-14, which contain 6, 7, 8 neutrons respectively, but all contain 6 protons. Each isotope of an element has a different nuclear energy state, and may have different stability.
NFC fiber network structure and dimensions in hydrogel resemble human ECM. Stiffness can be tuned to optimize the conditions for each cell type. Shear-thinning property of the material makes the gel ready to use without cross-linking or gelification step. The nanocellulose hydrogel can be completely degraded by cellulase enzyme treatment while retaining the 3D cell structures. NFC hydrogel in 3D cell culture offers a platform for various biomedical applications. Different cell lines and cell types have been cultured in NFC, including e.g. differentiation of human hepatic cells to functional organotypic cultures, and proliferation of human pluripotent stem cells. Organotypic liver cell cultures can be used in drug discovery for testing liver toxicity and metabolism of the novel drug candidates. The possibility to use the hydrogel with robotic dispensers enables its use in high throughput screening (HTS) formats. Additionally, 3D cell culture using wood-based nanocellulose hydrogel can be used for tissue engineering.
The FAO GM Foods Platform is a web platform where participating countries can share information on their assessments of the safety of genetically modified (recombinant-DNA) foods and feeds based on the Codex Alimentarius. It also allows for sharing of assessments of low-level GMO contamination (LLP, low-level presence). The platform was set up by the Food and Agriculture Organization of the United Nations, and was launched at the FAO headquarters in Rome on 1 July 2013. The information uploaded to the platform is freely available to be read. Agerskovgruppen Global Aquaculture Alliance
8 October – Tánaiste Micheál Martin said that the Department of Foreign Affairs had been in touch with the family of Kim Damti (22), an Irish-Israeli woman who was unaccounted for following the previous day's series of attacks launched by Hamas on Israel. On 11 October, Damti was confirmed dead. 10 October – Minister for Finance Michael McGrath and Minister for Public Expenditure, National Development Plan Delivery and Reform Paschal Donohoe announced Budget 2024, with three electricity credits for all households, a €12 increase to core social welfare payments and half-price travel for those aged under 25. 23 October – Yousef Palani was sentenced to two life sentences plus 20 years for the murder of two men and the stabbing of a third in Sligo, all of who he had sought out on a pretence of dating. 25 October – The Health Products Regulatory Authority (HPRA) said it had seized 254 units of falsified Semaglutide, a drug used for type 2 diabetes and as an unofficial aide to weight loss, during 2023. 27 October – Latest figures showed that homelessness in Ireland hit new records: 8,923 adults and 3,904 children accessed emergency accommodation in September 2023, bringing the total to 12,827 people.
Screens for biologically relevant protein-protein interactions have been performed using Tandem Affinity Purification (TAP) with the SBP-Tag and Protein A, for interaction proteomics and transcription factor complexes with the SBP-Tag and Protein G, for proteins that interact with the Dengue Virus protein DENV-2 NS4A with the SBP-Tag and the Calmodulin Tag. and for proteins that interact with protein phosphatase 2A (PP2A) with the SBP-Tag and the hemagglutinin (HA)-tag.
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.
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.