A practical reference on creatinine: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-07-14. Anything still debated is marked as such rather than presented as settled.
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.
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.
In aqueous solution, creatine monohydrate undergoes a slow conversion to creatinine, a cyclized degradation product. This reaction is pH- and temperature-dependent, and it proceeds faster in warm or alkaline conditions. Because the conversion is gradual, analytical measurements of creatine in solution must account for time and storage history. The equilibrium favors creatinine more strongly at higher temperatures, which is relevant to sample handling in laboratories and to beverage formulations. Refrigeration slows but does not entirely stop this process.
Quality assessment of creatine monohydrate typically uses high-performance liquid chromatography to separate creatine from creatinine and other impurities. Other methods include nuclear magnetic resonance spectroscopy, titration, and infrared spectroscopy for identity confirmation. Purity is often reported as a percentage of the labeled compound on a dry basis, while moisture content is measured separately. Because different analytical methods have different selectivity, comparing purity values across sources requires attention to the method and sample preparation.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | 15–25 °C | Protect from moisture, heat, and direct sunlight |
| Analytical method | HPLC with UV or RI detection | Separates creatine from creatinine and related impurities |
| Water content | About 12.1% w/w | Theoretical value for the monohydrate crystal |
| Degradation product | Creatinine | Formed by cyclization, especially in aqueous solution |
| Common assay specification | 98.0–102.0% | Range depends on the testing method and monograph |
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.
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.
Analytical methods for creatine monohydrate focus on identity, purity, and degradation products. High-performance liquid chromatography with ultraviolet detection is common, often at a wavelength near 210 nanometers. Titration and nuclear magnetic resonance spectroscopy can also quantify the parent compound. Pharmacopeial monographs specify tests for appearance, solubility, water content, and related substances, including creatinine. Purity values above 99 percent are typical for pharmaceutical-grade material, though supplement-grade products vary. Independent verification can detect label discrepancies.
Sourcing and verification of creatine monohydrate involve both manufacturing origin and third-party testing. Industrial production commonly starts with sarcosine and cyanamide, followed by crystallization to obtain the monohydrate. Some products are derived from animal sources, while others are synthesized from non-animal precursors. Certificates of analysis report assay, heavy metals, and microbial limits. Regulations differ by country: in the United States it is sold as a dietary supplement, whereas in the European Union it falls under food supplement rules.
== Forensic science and humanitarian work == The International Committee of the Red Cross (ICRC) uses forensic science for humanitarian purposes to clarify the fate of missing persons after armed conflict, disasters or migration, and is one of the services related to Restoring Family Links and Missing Persons. Knowing what has happened to a missing relative can often make it easier to proceed with the grieving process and move on with life for families of missing persons. Forensic science is used by various other organizations to clarify the fate and whereabouts of persons who have gone missing. Examples include the NGO Argentine Forensic Anthropology Team, working to clarify the fate of people who disappeared during the period of the 1976–1983 military dictatorship. The International Commission on Missing Persons (ICMP) used forensic science to find missing persons, for example after the conflicts in the Balkans. Recognising the role of forensic science for humanitarian purposes, as well as the importance of forensic investigations in fulfilling the state's responsibilities to investigate human rights violations, a group of experts in the late-1980s devised a UN Manual on the Prevention and Investigation of Extra-Legal, Arbitrary and Summary Executions, which became known as the Minnesota Protocol. This document was revised and re-published by the Office of the High Commissioner for Human Rights in 2016.
C.D.E. See: #Certified diabetes educator. C-peptide A substance the pancreas releases into the bloodstream in equal amounts to insulin. While being stored in pancreatic beta cells, proinsulin includes both insulin and C-peptide, which is freed before insulin secretion into the blood. Currently, since pharmaceutical insulin does not contain C-peptide, a C-peptide level test will show how much insulin the body is making. Insulin is prepared as two insulin molecules linked by a c-peptide. When insulin is secreted, C-peptide is released as well. It has in recent years been shown to have hormone properties, so far chiefly in connection with arterial vessel muscle tone. It has been shown to ameliorate some diabetic complications, such as neuropathy and microvascular damage. C-peptide varies much more between animal species than does insulin itself. Calcium channel blocker Calcium ions are used in many cells, including beta cells, as a signaling mechanism. Since it does not ordinarily pass through cell membranes, protein pores in cell membranes are used to provide a channel through which it can be 'pumped' – an activity which requires energy if done against a concentration gradient. A Ca+ channel blocker is a drug which interferes with the operation of (some?) such channels. They have widespread effects, since Ca+ is used for many purposes in assorted tissues.
== External links == Spallation Neutron Source Mercury 197 Mercury 197 decays to Gold 197 Kolarik, Zdenek; Renard, Edouard V. (2003). "Recovery of Value Fission Platinoids from Spent Nuclear Fuel. Part I PART I: General Considerations and Basic Chemistry" (PDF). Platinum Metals Review. 47 (2): 74–87. doi:10.1595/003214003X4727487. Archived from the original (PDF) on 2011-06-09. Kolarik, Zdenek; Renard, Edouard V. (2003). "Recovery of Value Fission Platinoids from Spent Nuclear Fuel. Part II: Separation Process" (PDF). Platinum Metals Review. 47 (2): 123–131. doi:10.1595/003214003X473123131. Archived from the original (PDF) on 2011-06-09. Kolarik, Zdenek; Renard, Edouard V. (2005). "Potential Applications of Fission Platinoids in Industry". Platinum Metals Review. 49 (2): 79. doi:10.1595/147106705X35263.
=== Brand names === Pioglitazone is marketed as Actos in the United States, Canada, the UK and Germany, Glustin in the European Union, Glizone and Pioz in India by Zydus Cadila and USV Limited, respectively, and Zactos in Mexico by Takeda Pharmaceuticals. On 17 August 2012, the US FDA announced its approval of the first generic version of Actos.
Sources: en.wikipedia.org
To regain the military initiative, the adoption of mine warfare as an integral strategy of PLAN was discussed at a 1969–70 SWAPO consultative congress held in Tanzania. PLAN's leadership backed the initiative to deploy land mines as a means of compensating for its inferiority in most conventional aspects to the South African security forces. Shortly afterwards, PLAN began acquiring TM-46 mines from the Soviet Union, which were designed for anti-tank purposes, and produced some homemade "box mines" with TNT for anti-personnel use. The mines were strategically placed along roads to hamper police convoys or throw them into disarray prior to an ambush; guerrillas also laid others along their infiltration routes on the long border with Angola. The proliferation of mines in South West Africa initially resulted in heavy police casualties and would become one of the most defining features of PLAN's war effort for the next two decades. On 2 May 1971 a police van struck a mine, most likely a TM-46, in the Caprivi Strip. The resulting explosion blew a crater in the road about two metres in diameter and sent the vehicle airborne, killing two senior police officers and injuring nine others. This was the first mine-related incident recorded on South West African soil. In October 1971, another police vehicle detonated a mine outside Katima Mulilo, wounding four constables. The following day, a fifth constable was mortally injured when he stepped on a second mine laid directly alongside the first.
molecular biology The branch of biology that studies biological activity at the molecular level, in particular the various mechanisms underlying the biological processes that occur in and between cells, including the structures, properties, synthesis, and modification of biomolecules such as proteins and nucleic acids, their interactions with the chemical environment and with other biomolecules, and how these interactions explain the observations of classical biology (which in contrast studies biological systems at much larger scales). Molecular biology relies largely on laboratory techniques of physics and chemistry to manipulate and measure microscopic phenomena. It is closely related to and overlaps with the fields of cell biology, biochemistry, and molecular genetics.
Banting House is a museum and former residence in London, Ontario, Canada. Known as the “Birthplace of Insulin,” it is the house where Sir Frederick Banting woke up at two o'clock in the morning on October 31, 1920 with the idea that led to the discovery of insulin. Since 1984, the house has been a museum dedicated to Banting's discovery and his life. An addition at the back houses the London & District Branch of the Canadian Diabetes Association. For many that have been touched by diabetes, the house is an emotional reminder of Banting's scientific contribution that saved their lives or the lives of their loved ones.
== Structure == The calcitonin receptor-like (CALCRL) protein is a class B G protein-coupled receptor (GPCR) characterized by seven transmembrane helices and a relatively large N-terminal extracellular domain (ECD) comprising 100–160 residues and three conserved disulfide bonds. CALCRL forms functional heterodimeric complexes with one of three single transmembrane receptor activity-modifying proteins (RAMPs), namely RAMP1, RAMP2, or RAMP3, which determine its ligand specificity. The extracellular domain of CALCRL consists of one α-helix, two antiparallel β-strands, five loop regions, and is stabilized by intramolecular disulfide bonds, which are crucial for ligand binding and specificity. The CALCRL/RAMP complex presents a unique ligand-binding pocket, enabling selective recognition of peptide agonists on the extracellular surface, which then triggers conformational changes in transmembrane helices to facilitate intracellular G-protein coupling and signal transduction.
=== Physical therapy === During the immobilization period, it is important to keep the foot flexible by lightly stretching the foot and calf regularly. As the plantar fascia recovers, physical therapy exercises help stabilize the ankle and correct gait patterns that may have contributed to the tear. Stretching and strengthening exercises decrease the chance of reinjury.
Sources: en.wikipedia.org
The GlyR agonism of sarcosine is relevant at concentrations frequently used in experimental settings (0.5–2 mM), complicating the pharmacological interpretation. Aside from effects on glycine-related structures and NMDA receptors, sarcosine has been shown to modulate AMPA receptor function and downstream mTOR signalling in rodent models of depression. Long-term sarcosine administration (21 days) ameliorated chronic unpredictable stress-induced depressive behaviour in rats In the rat forced swim test, a single systemic dose of sarcosine produced rapid antidepressant-like effects accompanied by increased phosphorylation of mTOR and its upstream kinases in the hippocampus, and these behavioural and molecular effects were abolished by pretreatment with the AMPA receptor antagonist NBQX or the mTOR inhibitor rapamycin. Sarcosine also increased phosphorylation of the GluR1 subunit at the protein kinase A site Ser845, a change commonly interpreted as enhanced AMPA receptor membrane insertion. Cryo-EM study published in 2025 resolved the structure of human GlyT1 in complex with sarcosine at 2.8 Å resolution, revealing the transporter in an occluded conformation.
=== Secondhand smoke === Secondhand smoke is a mixture of smoke from the burning end of a cigarette and the smoke exhaled from the lungs of smokers. It is involuntarily inhaled, lingers in the air for hours after cigarettes have been extinguished, and can cause a wide range of adverse health effects, including cancer, respiratory infections, and asthma. Nonsmokers who are exposed to second-hand smoke at home or work increase their heart disease risk by 25–30% and their lung cancer risk by 20–30%. Second-hand smoke has been estimated to cause 38,000 deaths per year, of which 3,400 are deaths from lung cancer in nonsmokers. Sudden infant death syndrome, ear infections, respiratory infections, and asthma attacks can occur in children who are exposed to second-hand smoke. Scientific evidence shows that no level of exposure to second-hand smoke is safe.
=== Treating rodenticide poisoning === Coumarin is used in the pharmaceutical industry as a precursor reagent in the synthesis of a number of synthetic anticoagulant pharmaceuticals. One subset, 4-hydroxycoumarins, act as vitamin K antagonists. They block the regeneration and recycling of vitamin K. Some of the 4-hydroxycoumarin anticoagulant class of chemicals are designed to have high potency and long residence times in the body, and these are used specifically as second generation rodenticides ("rat poison"). Death occurs after a period of several days to two weeks, usually from internal hemorrhaging. For humans, and for animals that have consumed either the rodenticide or rats poisoned by the rodenticide, treatment is prolonged administration of large amounts of vitamin K. This dosing must sometimes be continued for up to nine months in cases of poisoning by "superwarfarin" rodenticides such as brodifacoum. Oral vitamin K1 is preferred over other vitamin K1 routes of administration because it has fewer side effects.
RF(Arg-Phe)amide family 26 amino acid peptide, also known as P518, is a human protein. The 26-amino acid RF-amide peptide, P518 functions as a high-affinity ligand of GPR103. Both GPR103 and P518 precursor mRNA exhibited highest expression in brain. The 43-amino acid QRFP peptide, a longer form of the P518 peptide is necessary to exhibit full agonistic activity with GPR103. Intravenous administration QRFP caused release of aldosterone, suggesting that QRFP and GPR103 regulate adrenal function.
Sources: en.wikipedia.org
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.
In solution, creatine can cyclize spontaneously to creatinine. Heat and certain pH conditions increase the rate of this conversion. Dry crystalline material is more stable because the reaction requires water.
Typical storage is in a sealed container at room temperature, away from moisture and direct heat. These conditions reduce caking and slow degradation. Liquid products require more careful handling because creatine is less stable in water.
Dry, sealed creatine monohydrate can remain stable for years, but storage conditions affect its shelf life. Moisture, heat, and repeated opening of containers can reduce quality over time.