The short version of Guanidino group fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-08-03. Anything still debated is marked as such rather than presented as settled.
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.
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 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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C4H9N3O2·H2O | Monohydrate includes one water molecule per creatine molecule |
| Molar mass | 149.15 g/mol | Value for the monohydrate; anhydrous creatine is about 131.13 g/mol |
| Appearance | White crystalline powder | Odorless or nearly odorless in purified form |
| Solubility in water | About 13 g/L at 25 °C | Solubility increases with temperature and varies with pH |
| Common synonyms | Creatine hydrate; N-(aminoiminomethyl)-N-methylglycine | Monohydrate distinguishes it from anhydrous creatine |
Manufacturing processes can leave trace amounts of dicyandiamide, creatinine, or residual solvents, depending on the synthetic route and purification steps. Heavy metals, arsenic, and microbial contamination are also monitored for food or pharmaceutical grades. Particle size distribution can affect dissolution behavior and blending uniformity, so it may be specified for certain applications. Analytical results are reported on a dry basis or as-is basis, and the difference matters when comparing certificates of analysis. Open questions remain about how minor impurities influence long-term stability under varied storage conditions.
Stability studies typically examine the effects of temperature, humidity, and light on creatine monohydrate. Sealed containers stored in cool, dry conditions help limit moisture uptake and hydrolysis. Elevated temperature and high relative humidity can accelerate conversion to creatinine, especially in aqueous solutions. In solid dosage forms, excipients and processing steps may also affect stability. Published stability data are not fully consistent across studies because test conditions and analytical methods vary.
Quality control of creatine monohydrate relies on a combination of identity, purity, and moisture tests. High-performance liquid chromatography with ultraviolet detection is widely used to separate creatine from creatinine and other related nitrogenous compounds. Spectroscopic methods such as infrared and nuclear magnetic resonance provide structural confirmation. Because the material is a hydrate, water content is measured separately, often by Karl Fischer titration. These tests together establish whether a lot meets a defined specification.
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 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.
=== Chromatographic compression and spectral deconvolution === Unique VUV absorbance spectra not only enable unambiguous compound identification, and allows GC run times to be deliberately shortened. VUV detectors operate at ambient pressure and are thus not flow rate limited. GC run times can be reduced by increasing the GC column flow and oven temperature program rates. Flow rate-enhanced chromatographic compression utilizes VUV spectral deconvolution to resolve any co-elution that may result from shortening GC runtimes. VUV absorption is additive, meaning that overlapping peaks give a spectrum that corresponds to the sum absorbance of each compound. The individual contribution of each analyte can be determined if the VUV spectra for co-eluting compounds are stored in the VUV library. The ability to differentiate coeluting analyte spectra and use them to deconvolve the overlapping signals is demonstrated in Figure 4. The individual spectra of terpenes limonene and p-cymene are shown in Panel A along with the summed absorbance of the selected retention time window (blue region in Panel B) and the fit with VUV library spectra. The R2 >0.999 fit result confirms their identities, and enables the deconvolution of these and other terpenes analyzed by GC-VUV as featured in Panel B.
Films often portray mental illness through exaggerated or negative stereotypes, which can distort public understanding and reinforce stigma, and they have often been negative, inaccurate or violent representations. Often distorted or overrepresented to be more sensational. A side to the misrepresentation of people with mental illness as less able to engage in healthy living and adversity management is the overrepresentation of characters as erratic, violent, and dangerous; horror films are particularly notorious for crude depictions of mental illness as monstrous. Psychologists have advocated for more accurate depictions, when these often reinforce self-stigma, and make mentally ill individuals feel like they can become horrific killers too. The other side is its romantization, where in the effort to craft a compelling tale, film makers will often embellish, simplify, or decontextualize complex mental health conditions, resorting to unrealistic tropes where "willpower" or "love" can "conquer" mental illness. A study published by Scarf, et al. in 2020 looked at a recent example, the popular film Joker (2019), which portrays the lead character as a person with mental illness who becomes extremely violent. The study found that viewing the film "was associated with higher levels of prejudice toward those with mental illness." Additionally, the authors suggest, "Joker may exacerbate self-stigma for those with a mental illness, leading to delays in help seeking." Positive portrayals of mental illness have generally increased since the 20th century.
The regulation of drugs varies by jurisdiction. In some countries, such as the United States, they are regulated at the national level by a single agency. In other jurisdictions, they are regulated at the state level, or at both state and national levels by various bodies, as is the case in Australia. The role of therapeutic goods regulation is designed mainly to protect the health and safety of the population. Regulation is aimed at ensuring the safety, quality, and efficacy of the therapeutic goods which are covered under the scope of the regulation. In most jurisdictions, therapeutic goods must be registered before they are allowed to be marketed. There is usually some degree of restriction on the availability of certain therapeutic goods depending on their risk to consumers. Depending upon the jurisdiction, drugs may be divided into over-the-counter drugs (OTC) which may be available without special restrictions, and prescription drugs, which must be prescribed by a licensed medical practitioner in accordance with medical guidelines due to the risk of adverse effects and contraindications. The precise distinction between OTC and prescription depends on the legal jurisdiction. A third category, "behind-the-counter" drugs, is implemented in some jurisdictions. These do not require a prescription, but must be kept in the dispensary, not visible to the public, and be sold only by a pharmacist or pharmacy technician. Doctors may also prescribe prescription drugs for off-label use – purposes which the drugs were not originally approved for by the regulatory agency.
Sources: en.wikipedia.org
Following Viserys' death, this friction exploded into the Targaryen civil war known as the Dance of the Dragons, with the blacks supporting Rhaenyra's claim to the throne and the greens supporting Aegon II's claim. Viserys' official character description depicts him as a "level-headed decision maker" who presided over a peaceful, but challenging reign. Both the character of Viserys and Considine's performance received universal acclaim, many deeming him the best character in the show and one of the best characters in the Game of Thrones universe, as well as an improvement on his book counterpart.
=== Female === For females, parts of the vulva, especially the clitoris, as well as the perineum and anus, are erogenous zones. While the vagina as a whole is not especially sensitive, its lower third (the area close to the entrance), called "the anterior wall" or "the outer one-third" of the vagina contains the majority of the vaginal nerve endings, making it more sensitive to touch than the inner two-thirds of the vaginal barrel. It has concentrations of the nerve endings that can provide pleasurable sensations during sexual activity when stimulated. Within the anterior wall of the vagina, there is a patch of ribbed rough tissue which has a texture that is sometimes described as similar to the palate (the roof of a mouth) or a raspberry, and may feel spongy when a woman is sexually aroused. This is the urethral sponge, which may also be the location of an area that some women report is an erogenous zone; this is sometimes called the G-spot. When stimulated, it may lead to sexual arousal, an orgasm, or female ejaculation. The existence of the G-spot and whether or not it is a distinct structure is debated among researchers, as reports of its location vary from woman to woman, it appears to be nonexistent in some women, and scientists commonly believe that it is an extension of the clitoris.
Californium (98Cf) is an artificial element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was 245Cf in 1950. There are 20 known radioisotopes ranging from 237Cf to 256Cf and several short-lived nuclear isomers. The longest-lived isotope is 251Cf with a half-life of 898 years; followed by 249Cf (available isotopically pure from decay of berkelium) at 351 years.
=== Cancer === In vitro, when cells approach the Hayflick limit, the time to senescence can be extended by inactivating the tumor suppressor proteins p53 and Retinoblastoma protein (pRb). Cells that have been so-altered eventually undergo an event termed a "crisis" when the majority of the cells in the culture die. Sometimes, a cell does not stop dividing once it reaches a crisis. In a typical situation, the telomeres are shortened and chromosomal integrity declines with every subsequent cell division. Exposed chromosome ends are interpreted as double-stranded breaks (DSB) in DNA; such damage is usually repaired by reattaching the broken ends together. When the cell does this due to telomere-shortening, the ends of different chromosomes can be attached to each other. This solves the problem of lacking telomeres, but during cell division anaphase, the fused chromosomes are randomly ripped apart, causing many mutations and chromosomal abnormalities. As this process continues, the cell's genome becomes unstable. Eventually, either fatal damage is done to the cell's chromosomes (killing it via apoptosis), or an additional mutation that activates telomerase occurs. With telomerase activation some types of cells and their offspring become immortal (bypass the Hayflick limit), thus avoiding cell death as long as the conditions for their duplication are met. Many cancer cells are considered 'immortal' because telomerase activity allows them to live much longer than any other somatic cell, which, combined with uncontrollable cell proliferation is why they can form tumors.
Sources: en.wikipedia.org
In Germany, a radiation protection officer directs and supervises activities to ensure radiation protection when handling radioactive materials or ionizing radiation. Their duties are described in § 31-33 StrlSchV (in German) of the Radiation Protection Ordinance and § 13-15 RöV (in German) of the X-Ray Ordinance. They are appointed by the radiation protection officer, who is responsible for ensuring that all radiation protection regulations are observed.
Nanochemistry is an emerging sub-discipline of the chemical and material sciences that deals with the development of new methods for creating nanoscale materials. The term "nanochemistry" was first used by Ozin in 1992 as 'the uses of chemical synthesis to reproducibly afford nanomaterials from the atom "up", contrary to the nanoengineering and nanophysics approach that operates from the bulk "down"'. Nanochemistry focuses on solid-state chemistry that emphasizes synthesis of building blocks that are dependent on size, surface, shape, and defect properties, rather than the actual production of matter. Atomic and molecular properties mainly deal with the degrees of freedom of atoms in the periodic table. However, nanochemistry introduced other degrees of freedom that controls material's behaviors by transformation into solutions. Nanoscale objects exhibit novel material properties, largely as a consequence of their finite small size. Several chemical modifications on nanometer-scaled structures approve size dependent effects. Three specializations of nanochemistry are molecular nanotopology, nanointerface chemistry and nanoelectrochemistry. Nanochemistry is used in chemical, materials and physical science as well as engineering, biological, and medical applications. Silica, gold, polydimethylsiloxane, cadmium selenide, iron oxide, and carbon are materials that show its transformative power. Nanochemistry can make the most effective contrast agent of MRI out of iron oxide (rust) which can detect cancers and kill them at their initial stages.
Collagen alpha-2(IV) chain is a protein that in humans is encoded by the COL4A2 gene. This gene encodes one of the six subunits of type IV collagen, the major structural component of basement membranes. The C-terminal portion of the protein, known as canstatin, is an inhibitor of angiogenesis and tumor growth. Like the other members of the type IV collagen gene family, this gene is organized in a head-to-head conformation with another type IV collagen gene so that each gene pair shares a common promoter.
This self-regulation effect is achieved as the CO2 laser essentially stops ablating as soon as it comes in contact with the intraocular percolated liquid, which occurs as soon as the laser reaches the optimal residual intact layer thickness.
== Society and culture == Much medical research has been done into the causes of osteogenesis imperfecta, benefiting not only those with OI but medicine more broadly; in the ten years between 2006 and 2016, the many discoveries of non-collagen related recessive gene mutations, which still led in those who have them to the clinical signs of OI, led to numerous breakthroughs in medical understanding of the process of healthy bone development.
Sources: en.wikipedia.org
It is a crystalline form of creatine that contains one water molecule per creatine molecule. The compound occurs naturally in muscle tissue and is also produced synthetically for research and consumer products. The monohydrate label describes the solid's hydration state.
Creatine monohydrate contains creatine, but the two terms are not strictly interchangeable. The monohydrate includes water in the crystal, while creatine refers to the base molecule. Other creatine forms pair the molecule with different acids or carriers.
Dietary creatine is found mainly in meat and fish. The human body also synthesizes creatine from amino acids in the liver, kidneys, and pancreas. The monohydrate powder used in products is manufactured rather than extracted directly from food.
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.