If you have been reading about Karl Fischer titration and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-11-13. Where a claim depends on a specific study, the study is described rather than over-claimed.
Creatine monohydrate is sold as a dietary ingredient in some countries and as a food supplement in others. Regulatory frameworks vary, so purity limits, labeling rules, and permitted claims are not globally uniform. In the United States, it falls under dietary supplement rules, whereas the European Union treats it as a food supplement ingredient. Pharmacopeial monographs, where they exist, can provide public quality standards, but not every product is required to meet them. Questions about long-term effects and patterns of use remain areas of active study rather than settled regulatory findings.
Solid creatine monohydrate is generally stable when kept cool and dry, but it can hydrolyze to creatinine over time. Moisture, heat, and acidic conditions accelerate this conversion, which reduces assay values and changes the material's properties. Creatinine is a cyclic dehydration product that is also a normal human metabolite, so its presence in a sample is not necessarily a health concern by itself. In quality testing, creatinine is monitored as a marker of degradation and purity.
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.
In dry solid form, creatine monohydrate is relatively stable when protected from moisture and heat. The crystal lattice includes water, and exposure to high humidity can cause caking or gradual changes in powder flow. Elevated temperatures may accelerate decomposition, particularly if moisture is present. Studies generally report that sealed, dry material retains acceptable purity for extended periods, although exact shelf life depends on packaging and storage conditions. Light exposure is not usually considered a major factor for this compound.
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.
| Property | Value | Notes |
|---|---|---|
| Purity (typical) | ≥99% by HPLC | Supplement and pharmacopeial grades vary |
| Water content | ≈12.1% theoretical | Measured by Karl Fischer titration |
| Creatinine limit | Often ≤0.1% in pharmacopeial grade | Supplement specifications may differ |
| Storage conditions | 15–25 °C, low humidity | Away from heat and acidic environments |
| Common analytical methods | HPLC–UV, NMR, FTIR, Karl Fischer | Used for identity, assay, and water content |
In the body, creatine is obtained from dietary meat and fish and is also synthesized from arginine, glycine, and methionine. Muscle stores creatine and phosphocreatine, which participate in the rapid regeneration of adenosine triphosphate during short, intense activity. The monohydrate form is used in research because it is chemically defined, stable as a dry solid, and relatively inexpensive to produce. Questions remain about whether other creatine forms offer meaningful advantages in absorption or tissue retention, and findings vary across studies and populations.
Creatine monohydrate is a crystalline compound formed from creatine and one molecule of water. Creatine itself is a nitrogen-containing organic acid that occurs in vertebrate muscle and other tissues. The monohydrate designation refers to the water included in the crystal lattice, not to water added during manufacturing. Its chemical formula is commonly written as C4H9N3O2·H2O. The solid is typically a white, odorless powder with low solubility in water at room temperature. It is one of several creatine forms described in scientific and commercial literature.
The compound was identified in the nineteenth century after chemists isolated a nitrogenous substance from meat extracts. Later work established its role in muscle energy metabolism and its conversion to phosphocreatine. Chemical synthesis of creatine followed, and industrial production made the monohydrate widely available as a purified powder. Interest expanded in the late twentieth century when researchers began studying creatine supplementation and muscle physiology. Historical accounts sometimes differ on exact dates and attributions, but the broad sequence from tissue extracts to synthetic production is well documented.
Identity and purity are commonly assessed by high-performance liquid chromatography, often with ultraviolet detection, and by spectroscopic techniques such as infrared or nuclear magnetic resonance. These methods can distinguish creatine from creatinine and detect related impurities. Moisture content may be measured by Karl Fischer titration or loss on drying. Particle size, bulk density, and heavy metal limits are additional quality parameters. Not every product is tested by every method, so specifications depend on the intended use and regulatory framework.
Solid creatine monohydrate is generally stable when kept dry and protected from extremes of heat and humidity. In the presence of moisture, it can gradually convert to creatinine, a cyclic dehydration product that has little value for phosphocreatine synthesis. Elevated temperatures and acidic conditions accelerate this conversion in solution. Because the reaction is slow in cool, dry storage, typical shelf lives are measured in years rather than weeks. Packaging that limits moisture and oxygen exposure helps maintain purity.
Recommended storage usually involves a sealed container kept at room temperature, away from direct sunlight and moisture. High humidity can cause caking, which changes flow properties and may complicate accurate weighing. Repeated opening of containers exposes the powder to air and moisture, so smaller aliquots can reduce handling effects. Storage temperature ranges are not absolute requirements; they reflect conditions that slow degradation and preserve consistent physical characteristics. Clean, dry tools help prevent contamination during sampling.
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.
In solid form, creatine monohydrate is relatively stable when kept dry and away from heat. Moisture and elevated temperatures promote cyclization into creatinine, a related compound with no role in the phosphagen system. Degradation accelerates in aqueous solution, where the conversion can occur within hours to days depending on pH and temperature. Manufacturers typically recommend storage in sealed containers at room temperature, with relative humidity below 50 percent. Long-term stability data for opened containers are limited.
Radiation therapy is usually reserved for people who have tumours remaining after surgery. These people often also receive medication to lower GH levels. Radiation therapy is given in divided doses over four to six weeks. This treatment lowers GH levels by about 50 percent over 2 to 5 years. People monitored for more than 5 years show significant further improvement. Radiation therapy causes a gradual loss of production of other pituitary hormones with time. Loss of vision and brain injury, which have been reported, are very rare complications of radiation treatments.
AlphaFold 1 (2018) was built on work developed by various teams in the 2010s, work that looked at the large databases of related protein sequences now available from many different organisms (most without known 3D structures), to try to find changes at different residues (peptides) that appeared to be correlated, even though the residues were not consecutive in the main chain. Such correlations suggest that the residues may be close to each other physically, even though not close in the sequence, allowing a contact map to be estimated. Building on recent work prior to 2018, AlphaFold 1 extended this by estimating a probability distribution for the distances between residues, effectively transforming the contact map into a distance map. It also used more advanced learning methods than previously to develop the inference. The code was not made publicly available, except to run on sequences of proteins in the 2018 CASP competition.
BMPs for clinical use are produced using recombinant DNA technology (recombinant human BMPs; rhBMPs). Recombinant BMP-2 and BMP-7 are currently approved for human use. rhBMPs are used in oral surgeries. BMP-7 has also recently found use in the treatment of chronic kidney disease (CKD). BMP-7 has been shown in murine animal models to reverse the loss of glomeruli due to sclerosis. A 2022 study by researchers from the Mayo Clinic, Maastricht University, and Ethris GmBH, a biotech company that focuses on RNA therapeutics, found that chemically modified mRNA encoding BMP-2 promoted dosage-dependent healing of femoral osteotomies in male rats. The mRNA molecules were complexed within nonviral lipid particles, loaded onto sponges, and surgically implanted into the bone defects. They remained localized around the site of application. Compared to receiving rhBMP-2 directly, bony tissues regenerated after mRNA treatment displayed superior strength and less formation of massive callus.
The beta sheet (β-sheet, also β-pleated sheet) is a common motif of the regular protein secondary structure. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone hydrogen bonds, forming a generally twisted, pleated sheet. A β-strand is a stretch of polypeptide chain typically 3 to 10 amino acids long with backbone in an extended conformation. The supramolecular association of β-sheets has been implicated in the formation of the fibrils and protein aggregates observed in amyloidosis, Alzheimer's disease and other proteinopathies.
Amivantamab, sold under the brand name Rybrevant, is a bispecific monoclonal antibody used to treat non-small cell lung cancer. Amivantamab is a bispecific epidermal growth factor (EGF) receptor-directed and MET receptor-directed antibody. It is the first treatment for adults with non-small cell lung cancer whose tumors have specific types of genetic mutations: epidermal growth factor receptor (EGFR) exon 20 insertion mutations. The most common side effects include rash, infusion-related reactions, skin infections around the fingernails or toenails, muscle and joint pain, shortness of breath, nausea, fatigue, swelling in the lower legs or hands or face, sores in the mouth, cough, constipation, vomiting and changes in certain blood tests. Amivantamab was approved for medical use in the United States in May 2021, and in the European Union in December 2021. The US Food and Drug Administration considers it to be a first-in-class medication.
Sources: en.wikipedia.org
The first definition of the term bioinformatics was coined by Paulien Hogeweg and Ben Hesper in 1970, to refer to the study of information processes in biotic systems. This definition placed bioinformatics as a field parallel to biochemistry (the study of chemical processes in biological systems). Bioinformatics and computational biology involved the analysis of biological data, particularly DNA, RNA, and protein sequences. The field of bioinformatics experienced explosive growth starting in the mid-1990s, driven largely by the Human Genome Project and by rapid advances in DNA sequencing technology. Analyzing biological data to produce meaningful information involves writing and running software programs that use algorithms from graph theory, artificial intelligence, soft computing, data mining, image processing, and computer simulation. The algorithms in turn depend on theoretical foundations such as discrete mathematics, control theory, system theory, information theory, and statistics.
Apamin is an 18 amino acid globular peptide neurotoxin found in apitoxin (bee venom). Dry bee venom consists of 2–3% of apamin. Apamin selectively blocks SK channels, a type of Ca2+-activated K+ channel expressed in the central nervous system. Toxicity is caused by only a few amino acids, in particular cysteine1, lysine4, arginine13, arginine14 and histidine18. These amino acids are involved in the binding of apamin to the Ca2+-activated K+ channel. Due to its specificity for SK channels, apamin is used as a drug in biomedical research to study the electrical properties of SK channels and their role in the afterhyperpolarizations occurring immediately following an action potential.
CHO cells are the most common mammalian cell line used for mass production of therapeutic proteins such as monoclonal antibodies, used in 70% of therapeutic mAbs. They can produce recombinant protein on the scale of 3–10 grams per liter of culture. Products of CHO cells are suitable for human applications, as these mammalian cells perform human-like post-translational modifications to recombinant proteins, which is key to the functioning of several proteins. It is believed that CHO-K1 transgenic cells are characterized by higher monoclonal antibody expression at the expense of biomass accumulation, for example, based on CHO-K1, monoclonal antibody‑producing cell lines with productivity up to 6.5 grams per liter have been selected. Cell culture Drug development Preclinical development
The Department works at the intersection of organic chemistry (chemistry of natural products, chemistry of macrocyclic compounds, chemistry of elementorganic compounds), supramolecular chemistry (solution and self-process chemistry) and molecular biology. The head of the Department is Professor Igor S. Antipin, a corresponding member of the Russian Academy of Science, Doctor of Chemistry. The Department conducts research in the following fields:
"Bad and Boujee" is a song by American hip-hop group Migos featuring American rapper Lil Uzi Vert. Written alongside producer Metro Boomin and co-producer G Koop, it was originally released to the Quality Control Music YouTube channel on August 27, 2016 before being officially released on October 28 by Quality Control Music, 300 Entertainment, and Atlantic Records as the lead single from the group's second studio album Culture (2017). In late December 2016, "Bad and Boujee" became an Internet phenomenon, spawning many memes with the lyrics "rain drop, drop top". This viral trend, combined with Donald Glover's shoutout at the 2017 Golden Globes, would help its commercial performance and cause the song to spike into the top ten and later peak at number one on the US Billboard Hot 100 for the week of January 21, 2017, making it the first number one single for both Migos and Lil Uzi Vert. There were also many memes about member Takeoff's omission from the song. The single received a nomination for Best Rap Performance at the 60th Annual Grammy Awards. The track has acquired over 1 billion Spotify plays as of August 2025.
Sources: en.wikipedia.org
Brenipatide (INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name; developmental code name LY-3537031) is a dual agonist of glucagon-like peptide-1 (GLP-1) receptors and gastric inhibitory polypeptide (GIP) receptors. Brenipatide is under development by Eli Lilly and Company for the treatment of alcoholism, bipolar disorder, asthma, smoking withdrawal, cardiovascular disorders, liver disorders, metabolic disorders, and obesity. It is taken by subcutaneous injection once per month. The drug has a longer elimination half-life than tirzepatide or retatrutide. As of December 2025, it was in phase 3 clinical trials for alcoholism and bipolar disorder, phase 2 trials for asthma and smoking withdrawal, and phase 1 trials for cardiovascular disorders, liver disorders, metabolic disorders, and obesity. List of investigational antipsychotics List of investigational bipolar disorder drugs List of investigational substance-related disorder drugs
Lactation suppression Hyperprolactinemia Adjunctive therapy of prolactin-producing pituitary gland tumors (prolactinomas); Monotherapy of Parkinson's disease in the early phase; Combination therapy, together with levodopa and a decarboxylase inhibitor such as carbidopa, in progressive-phase Parkinson's disease; In some countries also: ablactation and dysfunctions associated with hyperprolactinemia (amenorrhea, oligomenorrhea, anovulation, nonpuerperal mastitis and galactorrhea); Treatment of uterine fibroids. Adjunctive therapy of acromegaly: Cabergoline has low efficacy in suppressing growth hormone levels and is highly efficient in suppressing hyperprolactinemia, which is present in 20–30% of acromegaly cases. Growth hormone and prolactin are similar structurally and have similar effects in many target tissues; therefore, targeting prolactin may help symptoms when growth hormone secretion cannot be sufficiently controlled by other methods. Cabergoline is frequently used as a first-line agent in the management of prolactinomas due to its higher affinity for D2 receptor sites, less severe side effects, and more convenient dosing schedule than the older bromocriptine, though in pregnancy bromocriptine is often still chosen since there is less data on safety in pregnancy for cabergoline.
Amyloid proteins deposit most commonly inside the knee, followed by hands, wrists, elbow, hip, and ankle, causing joint pain. In males with advanced age (>80 years), there is significant risk of wild-type transthyretin amyloid deposition in synovial tissue of knee joint, but predominantly in old age deposition of wild type transthyretin is seen in cardiac ventricles. ATTR deposits have been found in ligamentum flavum of patients that underwent surgery for lumbar spinal stenosis. In beta 2-microglobulin amyloidosis, males have high risk of getting carpal tunnel syndrome. Aβ2MG amyloidosis (Hemodialysis associated amyloidosis) tends to deposit in synovial tissue, causing chronic inflammation of the synovial tissue in knee, hip, shoulder and interphalangeal joints. Amyloid light chains deposition in shoulder joint causes enlarged shoulders, also known as "shoulder pad sign". Amyloid light chain depositions can also cause bilateral symmetric polyarthritis. The deposition of amyloid proteins in the bone marrow without causing plasma cell dyscrasias is called amyloidoma. It is commonly found in cervical, lumbar, and sacral vertebrae. Those affected may be presented with bone pain due to bone lysis, lumbar paraparesis, and a variety of neurological symptoms. Vertebral fractures are also common.
CGRP antagonists can be used for both acute migraine treatment as well as prophylactically. CGRP is a neuropeptide which is thought to induce migraines via vasodilation of cranial arteries. CGRP can also release inflammatory agents and cause nervous system sensitization. It is theorized that by antagonizing the CGRP receptor of the trigeminal ganglia, lowered CGRP is released and less migraine occurs. Erenumab is a highly selective human monoclonal antibody which is a promising new development in migraine treatment. It has low risk of hepatoxicity like gepants can have, due to being mostly eliminated via proteolysis. There have been some studies suggesting the benefit of using melatonin for prophylaxis of migraine, however, there is a lack of strength of evidence due to a low number of studies as well as conflicting results. Melatonin has a good safety profile but there have been rare instances of serious side effects. More studies are needed in order to suggest the therapeutic use of melatonin for prophylaxis of migraine.
As of 2019, AAV vectors have been used in over 250 clinical trials worldwide, approximately 8.3% of virus-vectored gene-therapy trials. Recently, promising results have been obtained from Phase 1 and Phase 2 trials for a number of diseases, including Leber's congenital amaurosis, hemophilia, congestive heart failure, spinal muscular atrophy, lipoprotein lipase deficiency, and Parkinson's disease. AAV based gene therapy products have entered the worldwide market following completion of successful clinical trials. The table below contains FDA approved gene therapies that have entered the American Market and possibly other markets.
Sources: en.wikipedia.org
A sealed container kept at room temperature and away from moisture is typical. Heat and humidity promote conversion to creatinine and can reduce assay values. Long-term storage under dry conditions helps maintain the original crystalline form.
Creatinine is a degradation product formed when creatine loses water and cyclizes. It can appear during storage, processing, or analysis if conditions are harsh. Quality specifications often set a maximum limit for creatinine to control purity.
No universal testing protocol applies across all markets. Some products follow pharmacopeial monographs, while others rely on manufacturer specifications and third-party certificates. Common tests include assay, water content, heavy metals, and microbial limits.
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.