A practical reference on Pharmacopeial monograph: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-11-29 and is reviewed periodically as new material appears.
Creatine is synthesized endogenously in humans, mainly in the liver, kidney, and pancreas, from the amino acids arginine, glycine, and methionine. Skeletal muscle stores much of the body's creatine, where it participates in the phosphocreatine system that buffers adenosine triphosphate during short, intense contractions. Dietary sources include meat and fish, so omnivorous diets provide additional creatine beyond endogenous production. Supplemental creatine monohydrate supplies the same molecule found in food and tissues, not a distinct drug or hormone. Research interest centers on its role in cellular energy transfer and its effects on muscle and other tissues.
Several creatine forms are sold, including monohydrate, anhydrous, hydrochloride, nitrate, citrate, and blends. Once dissolved, these forms deliver creatine, but they differ in molar mass, solubility, counterions, and water content. Creatine monohydrate has the largest body of published human data among these forms. Questions remain about whether any alternative form offers meaningful advantages in absorption, tolerability, or tissue uptake under practical conditions. The hydrate form's lower creatine content by mass is a compositional fact, not a statement about effectiveness.
Creatine monohydrate is a crystalline compound formed when one molecule of creatine associates with one molecule of water in the solid lattice. Its molecular formula is C4H11N3O3, and its molar mass is about 149.15 grams per mole. The material appears as a white, odorless powder that dissolves sparingly in water at room temperature. The monohydrate designation distinguishes it from anhydrous creatine, which lacks the bound water and has a lower molar mass. This hydrate is the most common commercial form of creatine used in nutritional and research settings.
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.
Creatine monohydrate is a crystalline compound formed when one molecule of creatine binds with one molecule of water. Creatine itself is a nitrogen-containing organic acid involved in cellular energy transfer, particularly in muscle and nerve tissue. The monohydrate form is the most common solid form used in research and commercial products because it is relatively stable and easy to handle. Its molecular formula is C4H9N3O2·H2O, and its molar mass is about 149.15 grams per mole.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C4H11N3O3 | Often written C4H9N3O2·H2O |
| Molar mass | 149.15 g/mol | Anhydrous creatine is 131.13 g/mol |
| Appearance | White crystalline powder | Odorless, fine or granular |
| Water solubility | About 13 g/L at 25 °C | Low; increases with temperature |
| Common synonyms | Creatine hydrate; N-carbamimidoylsarcosine monohydrate | CAS 6020-87-7 |
In the body, creatine is synthesized from arginine, glycine, and methionine, mainly in the liver and kidneys, and is also obtained from foods such as meat and fish. About 95% of body creatine is stored in skeletal muscle, where a fraction is phosphorylated to phosphocreatine. Phosphocreatine serves as a rapid reserve of high-energy phosphate for short bursts of ATP regeneration. The monohydrate form supplies creatine after dissolution and absorption, but it is not itself the active phosphorylated species.
Creatine was first identified in skeletal muscle extracts in the nineteenth century, and its role in phosphagen energy buffering was clarified in the twentieth century. The monohydrate salt became widely studied after methods for inexpensive synthesis and crystallization were developed. Modern research examines its effects on muscle energetics, recovery, and cognitive performance under specific conditions. Findings vary with population, exercise protocol, baseline creatine status, and measurement method. Studies often compare supplementation with placebo during controlled training or testing schedules.
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.
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.
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.
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.
Abraham White (March 8, 1908 – February 14, 1980) was a professor of biochemistry who made several important discoveries in his field during the middle of the 20th century and helped write a foundational textbook, Principles of Biochemistry, which was published in 1954. The book went through six editions before its authors retired. White was born in Cleveland, Ohio, to Morris and Lena White. His siblings were Essie and Julius ("Jay"). When he was about one year old, his family moved to Lafayette, Colorado, and then later to Denver. White earned his bachelor's and master's degrees at the University of Colorado and a Ph.D. degree in Physiological Chemistry at the University of Michigan in the laboratory of Howard B. Lewis. This was followed by a postdoctoral fellowship at the Yale School of Medicine with Hubert Bradford Vickery at the Connecticut Agricultural Experiment Station.
The transduction of the signal through the membrane by the receptor is not completely understood. It is known that in the inactive state, the GPCR is bound to a heterotrimeric G protein complex. Binding of an agonist to the GPCR results in a conformational change in the receptor that is transmitted to the bound Gα subunit of the heterotrimeric G protein via protein domain dynamics. The activated Gα subunit exchanges GTP in place of GDP which in turn triggers the dissociation of Gα subunit from the Gβγ dimer and from the receptor. The dissociated Gα and Gβγ subunits interact with other intracellular proteins to continue the signal transduction cascade while the freed GPCR is able to rebind to another heterotrimeric G protein to form a new complex that is ready to initiate another round of signal transduction. It is believed that a receptor molecule exists in a conformational equilibrium between active and inactive biophysical states. The binding of ligands to the receptor may shift the equilibrium toward the active receptor states. Three types of ligands exist: Agonists are ligands that shift the equilibrium in favour of active states; inverse agonists are ligands that shift the equilibrium in favour of inactive states; and neutral antagonists are ligands that do not affect the equilibrium. It is not yet known how exactly the active and inactive states differ from each other.
In the most common means for its production, cells make 5-oxo-ETE in a four step pathway that involves their stimulus-induced activation of the following pathway: a) the release of arachidonic acid (i.e. 5Z,8Z,11Z,14Z-eicosatetraenoic acid) from its storage sites in membrane phospholipids due to the activation of phospholipase A2 enzymes; b) oxygenation of this arachidonic acid by activated arachidonate 5-lipoxygenase (ALOX5) to form 5(S)-hydroperoxy-6E,8Z,11Z,14Z-eicosatetraenoic acid (5(S)-HpETE); c) reduction of this 5(S)-HpETE by ubiquitous cellular peroxidases to form 5(S)-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid (5(S)-HETE); and (d) the oxidation of 5(S)-HETE by a microsome-bound nicotinamide adenine dinucleotide phosphate (NADP+)-dependent dehydrogenase enzyme viz., 5-hydroxyeicosanoid dehydrogenase (5-HEDH), to form 5-oxo-ETE:
Binding of a ligand to a binding site on protein often triggers a change in conformation in the protein and results in altered cellular function. Hence binding site on protein are critical parts of signal transduction pathways. Types of ligands include neurotransmitters, toxins, neuropeptides, and steroid hormones. Binding sites incur functional changes in a number of contexts, including enzyme catalysis, molecular pathway signaling, homeostatic regulation, and physiological function. Electric charge, steric shape and geometry of the site selectively allow for highly specific ligands to bind, activating a particular cascade of cellular interactions the protein is responsible for.
The classical, histopathological definition of amyloid is an extracellular, proteinaceous fibrillar deposit exhibiting β-sheet secondary structure and identified by apple-green birefringence when stained with congo red under polarized light. These deposits often recruit various sugars and other components such as serum amyloid P component, resulting in complex, and sometimes inhomogeneous structures. Recently this definition has come into question as some classic, amyloid species have been observed in distinctly intracellular locations. A more recent, biophysical definition is broader, including any polypeptide that polymerizes to form a cross-β structure, in vivo or in vitro, inside or outside cells. Microbiologists, biochemists, biophysicists, chemists and physicists have largely adopted this definition, leading to some conflict in the biological community over an issue of language.
Sources: en.wikipedia.org
Therefore, Akt promotes G1 phase progression in a positive feedback loop. Akt promotes cyclin D1 translation via indirect activation of mTOR. mTOR increases translation of cyclin D1 by activating ribosomal protein S6K, and inhibiting eukaryotic translation initiation factor 4E-binding protein (4E-BP), thus increasing eIF4e activity. Akt both indirectly and directly regulates cyclin-dependent kinase (CDK) inhibitors p21Cip1 and p27Kip1, allowing cell cycle progression. Akt phosphorylates p27Kip1 at Thr157, preventing its nuclear import. In addition, Akt phosphorylates Thr145 and Ser146 of p21Cip1, preventing PCNA binding and decreasing stability. Akt phosphorylation of Foxo transcription factors also affects the cell cycle, as inhibitory phosphorylation of FoxO4 (also named AFX) prevents p27 gene expression. Akt phosphorylates many proteins involved in polymerisation and stabilisation of the actin cytoskeleton. In normal cells, this can either increase the stability of cytoskeleton components or promote migration via remodelling. Examples are listed below:
TMEM261 contains a domain of unknown function, DUF4536 (pfam15055), predicted as a helical membrane spanning domain about 45aa (Cys 47- Ser 92) in length with no known domain relationships. Two further transmembrane helical domains are predicted of lengths 18aa (Val 52-Ala 69) and 23aa (Pro 81-Ala 102]). There is also a low complexity region spanning 25aa (Thr 14-Ala 39). The tertiary structure for TMEM261 has not yet been determined. However, its protein secondary structure is mostly composed of coiled-coil regions with beta strands and alpha helices found within the transmembrane and domain of unknown function regions. The N-terminal region of TMEM261 is composed of a disordered region which contains the low complexity region that is not highly conserved amongst orthologues. A N-myristoylation domain is shown to be present in most TMEM261 protein variants. Post-translational modifications include myristoylation of the N-terminal Glycine residue (Gly2) of the TMEM261 protein as well as phosphorylation of Threonine 31.
In November 2016, India's Drug Consultative Committee announced it was embarking on establishing a definition of drugs which could be dispensed without a prescription. Prior to this, the general assumption was that any drug which did not fall into a prescription schedule could be purchased without a prescription. However, the needed definition had not been enacted by early 2018. The lack of a legal definition for OTC drugs has led to this US$4 billion market segment being effectively unregulated. In the Netherlands, there are four categories:
Clear Lake Audiotorium is a six-track promo EP by De La Soul given out to A-list DJs in 1994, the catalog number is TB 1093 (Side A, "THIS SIDE" is TB 1093 A and Side B "OTHER SIDE" is TB 1093 B). It was composed of four tracks from the group's album Buhloone Mindstate and two non-album tracks—"Sh.Fe.Mc's" featuring A Tribe Called Quest, and "Stix & Stonz" featuring The Fearless Four, Grandmaster Caz, and Prince Whipper Whip. With only 500 copies pressed (vinyl and CD), Clear Lake Audiotorium remains one of the most sought-after De La Soul releases to date. Originally pressed on clear/light green vinyl and packaged in a clear plastic sleeve, the record has since been bootlegged on black vinyl. On March 7, 2025, exactly 31 years after its original release, the EP was released officially on streaming releases, alongside a limited physical re-release.
Sources: en.wikipedia.org
Tens of thousands of three-dimensional protein structures have been determined by X-ray crystallography and protein nuclear magnetic resonance spectroscopy (protein NMR) and a central question in structural bioinformatics is whether it is practical to predict possible protein–protein interactions only based on these 3D shapes, without performing protein–protein interaction experiments. A variety of methods have been developed to tackle the protein–protein docking problem, though it seems that there is still much work to be done in this field. Other interactions encountered in the field include Protein–ligand (including drug) and protein–peptide. Molecular dynamic simulation of movement of atoms about rotatable bonds is the fundamental principle behind computational algorithms, termed docking algorithms, for studying molecular interactions.
There are several national and international bioanalytical organisations active throughout the world. Often they are part of a bigger organisation, e.g. Bioanalytical Focus Group and Ligand Binding Assay Bioanalytical Focus Group, which are both within the American Association of Pharmaceutical Scientists (AAPS) and FABIAN, a working group of the Analytical Chemistry Section of the Royal Netherlands Chemical Society. The European Bioanalysis Forum (EBF), on the other hand, is independent of any larger society or association.
In a topological transcriptome analysis, researchers profiled important proteins of the non-small cell lung cancer regulatory network and determined that TMEM125 exhibited different topological characteristics across cancerous and normal conditions, suggesting its criticality in lung cancer networks. This is consistent with post-translational modification analysis; TMEM125 phosphorylation suggests it may be involved in a signal transduction pathway or as a receptor protein. Additionally, its myristoylation sites suggests its involvement in signal transduction, apoptosis, and alternative extracellular protein export. TMEM125 was identified as a tetraspanin cell adhesion molecule enriched in oligodendrocytes, suggesting it may play a role in myelination. Additionally, its expression was not observed in differentiating oligodendrocytes in vitro, but was detected in oligodendrocytes from treated rat brains, which suggests its expression is regulated by the presence of axons.
Analgesics are frequently used in combination, such as the paracetamol and codeine preparations found in many non-prescription pain relievers. They can also be found in combination with vasoconstrictor drugs such as pseudoephedrine for sinus-related preparations, or with antihistamine drugs for people with allergies. While the use of paracetamol, aspirin, ibuprofen, naproxen, and other NSAIDs concurrently with weak to mid-range opioids (up to about the hydrocodone level) has been said to show beneficial synergistic effects by combating pain at multiple sites of action, several combination analgesic products have been shown to have few efficacy benefits when compared to similar doses of their individual components. Moreover, these combination analgesics can often result in significant adverse events, including accidental overdoses, most often due to confusion that arises from the multiple (and often non-acting) components of these combinations.
BLAST is an algorithm for comparing biomacromolecule primary structure, most often nucleotide sequence of DNA/RN, and amino acid sequence of proteins, stored in the bioinformatic databases, with the query sequence. The algorithm uses scoring of the available sequences against the query by a scoring matrix such as BLOSUM 62. The highest scoring sequences represent the closest relatives of the query, in terms of functional and evolutionary similarity. The database search by BLAST requires input data to be in a correct format (e.g. FASTA, GenBank, PIR or EMBL format). Users may also designate the specific databases to be searched, select scoring matrices to be used and other parameters prior to the tool run. The best hits in the BLAST results are ordered according to their calculated E-value (the probability of the presence of a similarly or higher-scoring hit in the database by chance).
Sources: en.wikipedia.org
It is the hydrated crystalline form of creatine, containing one bound water molecule per creatine unit. The compound is commonly used as a nutritional ingredient and as a research material.
Yes, endogenous synthesis occurs mainly in the liver, kidney, and pancreas. Meat and fish also contribute creatine to the diet.
Other forms contain creatine paired with different counterions or lacking water, so their mass and solubility differ. After dissolution, creatine itself is the shared active molecule.
Creatine monohydrate is the hydrated solid form of creatine, a nitrogen-containing compound involved in cellular energy metabolism. It consists of one creatine molecule associated with one water molecule in a crystal lattice.