guanidinoacetate comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-05-01. Numbers and descriptions here follow the published literature rather than marketing material.
Solid creatine monohydrate is relatively stable when kept dry and sealed, but heat and moisture accelerate its conversion to creatinine. This degradation involves intramolecular cyclization, a process that removes water and forms a less useful compound for phosphocreatine metabolism. Powder stored under cool, dry conditions can remain within specification for extended periods, though exact shelf life depends on packaging, humidity, and initial purity. Aqueous solutions degrade faster than dry powder, with pH and temperature influencing the rate. Because degradation is gradual, analytical testing is used to confirm potency at manufacture and during stability studies.
Quality control for creatine monohydrate typically combines identity, assay, and impurity tests. High-performance liquid chromatography with ultraviolet detection is common for separating creatine from creatinine and related substances. Nuclear magnetic resonance and infrared spectroscopy can confirm molecular structure, while titration may assess acid-base content. Moisture content, heavy metals, residual solvents, and microbial limits are checked according to applicable standards. These tests help distinguish compliant material from powders that have degraded, been diluted, or contain manufacturing residues.
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.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | 15–25 °C | Cool, dry, sealed |
| Relative humidity | Below 60% | Moisture promotes caking and degradation |
| Degradation product | Creatinine | Forms by cyclization, especially in solution |
| Assay method | HPLC with UV detection | Often paired with identity tests |
| Aqueous stability | Hours to days at room temperature | Depends on pH, temperature, concentration |
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.
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.
Chuang, R.S., Jaffe, H., Cribbs, L., Perez-Reyes, E., Swartz, K.J. (1998). Inhibition of T-type voltage-gated calcium channels by a new scorpion toxin. Nature Neuroscience 1(8), 668–674. [1] Sidach, S.S., Mintz, I.M. (2002). Kurtoxin, a gating modifier of neuronal high- and low threshold Ca channels. The Journal of Neuroscience, 22(6), 2023–2034. [2]
Spironolactone has been found to decrease the bioavailability of high doses of oral estradiol. Although widely employed, the use of spironolactone as an antiandrogen in transgender women has recently been questioned due to the various shortcomings of the medication for such purposes. Cyproterone acetate is an antiandrogen and progestin which is used in the treatment of numerous androgen-dependent conditions and is also used as a progestogen in birth control pills. It works primarily as an antigonadotropin, secondarily to its potent progestogenic activity, and strongly suppresses gonadal androgen production. Cyproterone acetate at a dosage of 5 to 10 mg/day has been found to lower testosterone levels in men by about 50 to 70%, while a dosage of 100 mg/day has been found to lower testosterone levels in men by about 75%. The combination of 25 mg/day cyproterone acetate and a moderate dosage of estradiol has been found to suppress testosterone levels in transgender women by about 95%. In combination with estrogen, 10, 25, and 50 mg/day cyproterone acetate have all shown the same degree of testosterone suppression. In addition to its actions as an antigonadotropin, cyproterone acetate is an androgen receptor antagonist. However, this action is relatively insignificant at low dosages, and is more important at the high doses of cyproterone acetate that are used in the treatment of prostate cancer (100–300 mg/day). Cyproterone acetate can cause elevated liver enzymes and liver damage, including liver failure.
== Etymology == The word "lich" is derived from the Old English līċ, meaning "corpse". It is cognate with modern German Leiche, modern Danish lig, and modern Dutch lijk, all of which also mean "corpse".
Sources: en.wikipedia.org
== Interactions == GSTP1 has been shown to interact with Fanconi anemia, complementation group C and MAPK8. GST-Pi is expressed in many human tissues, particularly in the biliary tree, renal distal convoluted tubules and lungs.
To overcome this, several alternative methods have been proposed, such as the determination of halo diameter in agar-gelified milk, colorimetric measurement, or determination of the rate of degradation of casein previously labeled with either a radioactive tracer or a fluorochrome compound. All these methods use casein as the substrate to quantify proteolytic or milk-clotting activities.
UHDTV-1 is 3840 pixels wide by 2160 pixels tall (8.3 megapixels), which is four times as many pixels as the 1920 × 1080 (2.07 megapixels) of 1080p HDTV (full HDTV). Also known as 2160p, and 4K UHD. Although roughly similar in resolution to 4K digital cinema formats, it should not be confused with other 4K resolutions such as the 4096 × 2160 DCI 4K/Cinema 4K. The total number of pixels of RGB stripe type is 8.3 megapixels. UHDTV-2 is 7680 pixels wide by 4320 pixels tall (33.18 megapixels), also referred to as 4320p and 8K UHD, which is sixteen times as many pixels as 1080p HDTV, which brings it closer to the detail level of 15/70 mm IMAX. NHK advertises the 8K UHDTV format with 22.2 surround sound as Super Hi-Vision, which can be broadcast with H.264 codecs.
Fabrication and coating of nanodevices and medical implants to increase biocompatibility. Emulsifiers in food industry and personal care products. Hydrophobins' high stability can be very useful in the coating of surfaces of prolonged use or under harsh conditions. The easy dissociation of a class II hydrophobin monolayer might be desirable and this can easily be achieved by the use of detergents and alcohols. The use of hydrophobins in protein purification, drug delivery and cell attachment has been reported. For more about the potential biotechnological applications of hydrophobins see Hektor & Scholtmeijer (2005) and Cox & Hooley (2009).
Sources: en.wikipedia.org
Keep it in a sealed container in a cool, dry place away from direct heat and moisture. Dry powder is more stable than prepared solutions.
It can cyclize into creatinine, particularly in water or under heat. Creatinine does not support phosphocreatine energy buffering in the same way.
Laboratories commonly use chromatographic methods such as HPLC, along with spectroscopy and titration, to confirm identity and quantity. Moisture, elemental impurities, and microbial limits may also be tested.
It is a compound made of creatine bound to one water molecule. It appears as a white crystalline powder and is the most common solid form of creatine used in research and supplements.