Urea

This Urea is a moisturizing substance (humectant) at low doses (3-5%), which can be added to homemade care products such as serums and creams to make them more hydrating. It occurs naturally in urine and sweat. The powder itself does not smell like this.

Allantoin is a more concentrated alternative to Urea - 0.2% allantoin is equal to 10% urea.

It is soluble in water, and most stable at a pH of 6.2. At a lower pH, it decomposes into ammonium cyanate and then into ammonium and CO2. This reaction is accelerated when heated. Urea must therefore be added in the cooling phase.

Interesting fact: urea is the first substance ever (1828) to be synthesized in a lab.