Urea or carbamide is an organic compound with the chemical formula CO(NH2)2. Urea serves an important role in the metabolism of nitrogen-containing compounds by animals, and is the main nitrogen-containing substance in the urine of mammals. It is a colorless, odorless solid, highly soluble in water, and practically non-toxic (LD50 is 15 g/kg for rats). Dissolved in water, it is neither acidic nor alkaline. The body uses it in many processes, most notably nitrogen excretion.
Urea in concentrations up to 10 M is a powerful protein denaturant as it disrupts the noncovalent bonds in the proteins. This property can be exploited to increase the solubility of some proteins. A mixture of urea and choline chloride is used as a deep eutectic solvent, a type of ionic liquid. Urea-containing creams are used as topical dermatological products to promote rehydration of the skin. By virtue of its tendency to form a porous framework, urea has the ability to trap many organic compounds.
- “19th WHO Model List of Essential Medicines (April 2015)” (PDF). WHO. April 2015. Retrieved May 10, 2015.
- Godfrey, Peter; Brown, Ronald; Hunter, Andrew (1997). “The shape of urea”. Journal of Molecular Structure. 413–414: 405–414.