Everything below concerns guanidinoacetate. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-04-12. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
As a supplement, creatine monohydrate is studied for its effects on muscle performance and recovery. The compound is often described as an ergogenic aid, meaning it may support physical work capacity. Research typically compares it with placebo or other forms, such as citrate or nitrate, under controlled conditions. Questions remain about the optimal dose and long-term effects in different populations, and findings are not uniform across all studies. The monohydrate form remains the most extensively tested.
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.
In animals, creatine is synthesized mainly in liver, kidney, and pancreas from arginine, glycine, and methionine. The first committed step transfers a guanidino group from arginine to glycine, forming guanidinoacetate. Subsequent methylation by S-adenosylmethionine yields creatine. Dietary sources include meat and fish; endogenous synthesis supplies part of the body pool. Most creatine is stored in skeletal muscle, where it is converted to phosphocreatine and participates in rapid regeneration of adenosine triphosphate during short, intense activity.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C4H9N3O2·H2O | Monohydrate form; anhydrous is C4H9N3O2 |
| Molar mass | 149.15 g/mol | For the monohydrate |
| Appearance | White crystalline powder | Odorless, slightly bitter taste |
| Solubility in water | ~13 g/L at 25 °C | Poorly soluble; increases with temperature |
| CAS Registry Number | 6020-87-7 | For creatine monohydrate |
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.
Creatine monohydrate is a crystalline organic compound formed from creatine and water in a one-to-one ratio. It belongs to the guanidino family and contains a methylated guanidine group attached to an acetate-like chain. The solid is commonly described as a white, odorless powder with a mildly bitter taste. Its molecular formula is C4H11N3O3·H2O, and the hydrated form is the most widely traded grade. The compound occurs naturally in vertebrate muscle and brain tissue, where it participates in rapid energy buffering.
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.
== Clinical trials == ACD856 has completed phase 1 clinical trials for Alzheimer's disease. As of May 2024, it was in the preclinical stage of development for depressive disorders, sleep disorders, and traumatic brain injuries. Two phase 1 trials had been completed by 2022. A further phase 1b trial, assessing the safety and tolerability of repeated higher doses, reached its last patient visit in April 2026, and results were reported in June 2026. A phase 2 clinical trial in Alzheimer's disease was expected to start in 2026, supported by a €2.5 million European Innovation Council Accelerator grant awarded in 2025. The drug was developed by AlzeCure Pharma AB, which in July 2026 out-licensed worldwide rights to ACD856 and the NeuroRestore platform to the Danish company QuantumCell ApS for US$12 million upfront, with development and commercial milestone payments that could exceed US$2.2 billion.
==== Protein purification and separation ==== By immobilizing proteins to polymer nanoparticles or polymer/inorganic hybrid nanoparticles (such as polymer-stabilized iron oxide nanoparticles), proteins or their affinity ligands can be separated from complex solutions by applying magnetic fields or centrifugation. Lipase attached to iron oxide nanoparticles maintained 85% biological activity after 30 reaction and separation cycles. As the appropriate target is combined with magnetic nanoparticles, the selected target can be magnetically separated directly from natural biological fluids, which offers a fast, gentle, extensible, and easy to automate separation technique. The simplicity of magnetic separation has been applied in a number of disciplines, including mineral processing wastewater treatment, molecular biology, cell sorting, and clinical diagnostics.
=== Energy === Formic acid can be used directly in formic acid fuel cells or indirectly in hydrogen fuel cells. Electrolytic conversion of electrical energy to chemical fuel has been proposed as a large-scale source of formate by various groups. The formate could be used as feed to modified E. coli bacteria for producing biomass. Natural methylotroph microbes can feed on formic acid or formate Formic acid has been considered as a means of hydrogen storage. The co-product of this decomposition, carbon dioxide, can be rehydrogenated back to formic acid in a second step. Formic acid contains 53 g/L hydrogen at room temperature and atmospheric pressure, which is three and a half times as much as compressed hydrogen gas can attain at 350 bar pressure (14.7 g/L). Pure formic acid is a liquid with a flash point of 69 °C, much higher than that of gasoline (−40 °C) or ethanol (13 °C). It is possible to use formic acid as an intermediary to produce isobutanol from CO2 using microbes.
Sources: en.wikipedia.org
== Structure == All proteins of the NF-κB family share a Rel homology domain in their N-terminus. A subfamily of NF-κB proteins, including RelA, RelB, and c-Rel, have a transactivation domain in their C-termini. In contrast, the NF-κB1 and NF-κB2 proteins are synthesized as large precursors, p105 and p100, which undergo processing to generate the mature p50 and p52 subunits, respectively. The processing of p105 and p100 is mediated by the ubiquitin/proteasome pathway and involves selective degradation of their C-terminal region containing ankyrin repeats. Whereas the generation of p52 from p100 is a tightly regulated process, p50 is produced from constitutive processing of p105. The p50 and p52 proteins have no intrinsic ability to activate transcription and thus have been proposed to act as transcriptional repressors when binding κB elements as homodimers. Indeed, this confounds the interpretation of p105-knockout studies, where the genetic manipulation is removing an IκB (full-length p105) and a likely repressor (p50 homodimers) in addition to a transcriptional activator (the RelA-p50 heterodimer).
In biological research, transgenic fruit flies (Drosophila melanogaster) are model organisms used to study the effects of genetic changes on development. Fruit flies are often preferred over other animals due to their short life cycle and low maintenance requirements. They also have a relatively simple genome compared to many vertebrates, with typically only one copy of each gene, making phenotypic analysis easy. Drosophila have been used to study genetics and inheritance, embryonic development, learning, behavior, and aging. The discovery of transposons, in particular the p-element, in Drosophila provided an early method to add transgenes to their genome, although this has been taken over by more modern gene-editing techniques. Due to their significance to human health, scientists are looking at ways to control mosquitoes through genetic engineering. Malaria-resistant mosquitoes have been developed in the laboratory by inserting a gene that reduces the development of the malaria parasite and then use homing endonucleases to rapidly spread that gene throughout the male population (known as a gene drive). This approach has been taken further by using the gene drive to spread a lethal gene. In trials the populations of Aedes aegypti mosquitoes, the single most important carrier of dengue fever and Zika virus, were reduced by between 80% and by 90%. Another approach is to use a sterile insect technique, whereby males genetically engineered to be sterile out compete viable males, to reduce population numbers. Other insect pests that make attractive targets are moths.
== Epidemiology, history, and culture == Acromegaly affects about 6 per 100,000 people. It is most commonly diagnosed in middle age. Males and females are affected with equal frequency. It was first described in the medical literature by Nicolas Saucerotte in 1772. The term is from the Greek ἄκρον (akron) meaning "extremity", and μέγα (mega) meaning "large".
Sources: en.wikipedia.org
It is a compound made of creatine bound to one water molecule. It appears as a white crystalline powder and is the most common solid form of creatine used in research and supplements.
Creatine is converted to phosphocreatine in muscle, which helps regenerate adenosine triphosphate during brief, high-intensity activity. The body also obtains creatine from foods such as meat and fish.
The creatine molecule is the same whether from food or supplements, but the monohydrate form includes a water molecule in its crystal structure. Once dissolved, the monohydrate and food-derived creatine are chemically identical in the body.
Creatine is the base compound, while creatine monohydrate includes one water molecule per creatine molecule in its crystal structure. The monohydrate form is common in supplements and analytical standards. The body uses creatine itself after the water is removed or dissociated.