creatinine raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-01-24 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical formula (monohydrate) | C4H11N3O3 | Includes one water molecule per creatine unit. |
| Molecular weight | 149.15 g/mol | Calculated for the monohydrate; anhydrous creatine is 131.13 g/mol. |
| Appearance | White crystalline powder | Odorless; particle size can vary by manufacturing. |
| CAS Registry Number | 6020-87-7 | Identifies creatine monohydrate; creatine base is 57-00-1. |
| Common synonyms | Creatine hydrate; methylguanidoacetic acid monohydrate | Naming varies by registry and supplier. |
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.
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.
Creatine monohydrate is stable under dry, cool conditions but can degrade when exposed to moisture and heat. In solution, it undergoes hydrolysis to creatinine, a cyclic derivative with little role in phosphagen energy transfer. The rate of conversion increases with temperature, storage time, and acidic or alkaline pH. Solid material kept in a sealed container at room temperature generally retains its composition for extended periods. Moisture uptake is a primary concern because it can accelerate breakdown and caking.
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.
For services to Music. International list John Adams. Chair, British Retirement Home Association, Portugal. For services to the Community and Voluntary Organisations in Portugal. Joy Atkinson. Desk Officer, Foreign, Commonwealth and Development Office. For services to British Foreign Policy. Nicola Jane Barrett. Head, Corporate Services, British Embassy Moscow, Russia. For services to British Foreign Policy. Liza Barry. Deputy Director, Foreign, Commonwealth and Development Office. For services to National Security. Geoffrey James Booker. Founding Chairman and Field Director, The Quicken Trust and The GB Trust. For services to the community in Kabubbu, Uganda. Geraldine Elizabeth Booker. Director of Development, The Quicken Trust and The GB Trust. For services to the community in Kabubbu, Uganda. Sian Bowsley. Head, Agrifood and Sanitary and Phytosanitary (SPS), Windsor Framework Taskforce, Foreign, Commonwealth and Development Office. For services to British Foreign Policy. Christopher Mark Broadbent. Team Leader, Foreign, Commonwealth and Development Office. For services to National Security. Keith John Buckley. Chairman, British Chamber of Commerce, Macao; Chairman, The Lighthouse Club (Macao Branch) charity. For services to the Local Community and British Interests in Macao. Scott Arthur Burgess. Acting Overseas Security Manager, British Embassy Tehran, Iran. For services to the British Embassy Tehran. Adina Diana Esther Munroe-Charlow. Chairperson, Royal British Legion, Bahamas Branch. For services to Veterans in The Bahamas. Gillian Clasby.
Citrullination or deimination is the conversion of the amino acid arginine in a protein into the amino acid citrulline. Citrulline is not one of the 20 standard amino acids encoded by DNA in the genetic code. Instead, it is the result of a post-translational modification. Citrullination is distinct from the formation of the free amino acid citrulline as part of the urea cycle or as a byproduct of enzymes of the nitric oxide synthase family. Enzymes called arginine deiminases catalyze the deimination of free arginine, while protein arginine deiminases or peptidylarginine deiminases (PADs) replace the primary ketimine group by a ketone group. Arginine is positively charged at a neutral pH, whereas citrulline has no net charge. This increases the hydrophobicity of the protein, which can lead to changes in protein folding, affecting the structure and function. The immune system can attack citrullinated proteins, leading to autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. Fibrin and fibrinogen may be favored sites for arginine deimination within rheumatoid joints. Test for presence of anti-citrullinated protein antibodies are highly specific (88–96%) for rheumatoid arthritis, about as sensitive as rheumatoid factor (70–78%) for diagnosis of RA, and are detectable from even before the onset of clinical disease. Citrullinated vimentin may be an autoantigen in rheumatoid arthritis and other autoimmune diseases, and is used to study rheumatoid arthritis.
A pariah field, cast out by the scientific establishment. Between cold fusion and respectable science there is virtually no communication at all. Cold fusion papers are almost never published in refereed scientific journals, with the result that those works don't receive the normal critical scrutiny that science requires. On the other hand, because the Cold-Fusioners see themselves as a community under siege, there is little internal criticism. Experiments and theories tend to be accepted at face value, for fear of providing even more fuel for external critics, if anyone outside the group was bothering to listen. In these circumstances, crackpots flourish, making matters worse for those who believe that there is serious science going on here.
However, it is provided in a tough fibreboard carton rather than in individual unitised polyethylene bags. It is a group feeding solution, and it is impractical to use on an individual basis for main meals. There are a multiple of group-sized retort pouches – 500 gram as opposed to 250 gram, several of which are required to be heated in order to provide a complete meal. Examples include Beef & Blackbean Sauce, Chicken Satay. Common elements include rice and vegetables such as corn, potatoes and carrots. The accessories such as snacks are consumable and can be carried individually. There are five menu choices, and each Combat Ration Five Man weighs around 10 kg (22 lb). Patrol Ration One Man is a complete 24-hour ration pack that contains freeze dried main meals, meaning that the total weight of each pack is reduced, however a correspondingly higher quantity of water must be carried in order to reconstitute the main meal. Otherwise, it is similar to the Combat Ration One Man. It is packed in tough clear polyethylene bags and is available in five menu choices.
== 1980s == Though contacts were restricted after the Gleneagles Agreement in 1977, there were controversial tours in 1980 by the British Lions and by France, in 1981 by Ireland, and in 1984 by England. In 1986, though a Lions tour was cancelled, South Africans played in all-star matches in Cardiff and in London marking the IRB centenary. South Africa was excluded from the first two Rugby World Cups, in 1987 and 1991. In 1982 the political relationship between Australia and Argentina was also damaged due to the Falklands War. The Soviet Union supposedly turned down its invitation to the 1987 Rugby World Cup, because of its distaste for the apartheid regime of South Africa. However, South Africa was not invited in the end. While the Great Soviet Encyclopedia states that rugby is popular in Great Britain, New Zealand, France, Romania and Australia, it tellingly makes no mention of South Africa. Chris Thau says that France approached the USSR before 1987 on the issue, and that the Soviets said that they would be happy to participate if South Africa was not invited. In the end, South Africa was not invited, but the USSR did not attend either. It has been said that:
Sources: en.wikipedia.org
RNA polymerase Often abbreviated RNAP or RNApol. Any of a class of polymerase enzymes that synthesize RNA molecules from a DNA template. RNA polymerases are essential for transcription and are found in all living organisms and many viruses. They build long single-stranded polymers called transcripts by adding ribonucleotides one at a time in the 5'-to-3' direction, relying on the template provided by the complementary strand to transcribe the nucleotide sequence faithfully. Unlike DNA polymerases, RNA polymerases notably do not require oligonucleotide primers to initiate synthesis; i.e. they are capable of synthesizing RNA molecules de novo.
The two halves of the atom A will end up on opposite edges of the strip, over two atoms A1 and A2 of the graphene. The line from A1 to A2 will correspond to the circumference of the cylinder that went through the atom A, and will be perpendicular to the edges of the strip. In the graphene lattice, the atoms can be split into two classes, depending on the directions of their three bonds. Half the atoms have their three bonds directed the same way, and half have their three bonds rotated 180 degrees relative to the first half. The atoms A1 and A2, which correspond to the same atom A on the cylinder, must be in the same class. It follows that the circumference of the tube and the angle of the strip are not arbitrary, because they are constrained to the lengths and directions of the lines that connect pairs of graphene atoms in the same class. Let u and v be two linearly independent vectors that connect the graphene atom A1 to two of its nearest atoms with the same bond directions. These are the graphene's lattice vectors. For example, if one numbers consecutive carbons around a graphene cell with C1 to C6, then u can be the vector from C1 to C3, and v the vector from C1 to C5. Then, for any other atom A2 with same class as A1, the vector from A1 to A2 can be written as a linear combination n u + m v, where n and m are integers. And, conversely, each pair of integers (n,m) defines a possible position for A2.
Humans can experience all of the above-mentioned varieties of pair bonds. These bonds can be temporary or last a lifetime. They also engage in social pair bonding, where two form a close relationship that does not involve sex. Like in other vertebrates, pair bonds are created by a combination of social interaction and biological factors including neurotransmitters like oxytocin, vasopressin, and dopamine. Pair bonds are a biological phenomenon and are not equivalent to the human social institution of marriage. Married couples are not necessarily pair bonded. Marriage may be a consequence of pair bonding and vice versa. One of the functions of romantic love is pair bonding.
Each chemical element has a unique atomic number (Z— for "Zahl", German for "number") representing the number of protons in its nucleus. Each distinct atomic number therefore corresponds to a class of atom: these classes are called the chemical elements. The chemical elements are what the periodic table classifies and organizes. Hydrogen is the element with atomic number 1; helium, atomic number 2; lithium, atomic number 3; and so on. Each of these names can be further abbreviated by a one- or two-letter chemical symbol; those for hydrogen, helium, and lithium are respectively H, He, and Li. Neutrons do not affect the atom's chemical identity, but do affect its weight. Atoms with the same number of protons but different numbers of neutrons are called isotopes of the same chemical element. Naturally occurring elements usually occur as mixes of different isotopes; since each isotope usually occurs with a characteristic abundance, naturally occurring elements have well-defined atomic weights, defined as the average mass of a naturally occurring atom of that element. All elements have multiple isotopes, variants with the same number of protons but different numbers of neutrons. For example, carbon has three naturally occurring isotopes: all of its atoms have six protons and most have six neutrons as well, but about one per cent have seven neutrons, and a very small fraction have eight neutrons. Isotopes are never separated in the periodic table; they are always grouped together under a single element.
Sources: en.wikipedia.org
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.
Yes. Meat, fish, and other animal tissues contain creatine. Cooking can convert some creatine to creatinine, which has no role in phosphocreatine energy buffering. Plant foods contain little or no creatine.
Creatinine is a cyclic breakdown product formed from creatine and phosphocreatine. It is filtered by the kidneys and commonly measured in blood and urine as a marker of renal function. Creatine monohydrate is a supplement ingredient and research chemical, not the same 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.