Urea is used in cosmetics as a:
- Buffering Agent
- Humectant moisturizer
“Utilized for decades by dermatologists to treat dry skin; has been demonstrated to stimulate Aquaporin-3 expression in keratinocytes.” – Grether-Beck S, Felsner I, Brenden H, et al. Urea uptake enhances barrier function and antimicrobial defense in humans by regulating epidermal gene expression [published online ahead of print March 15, 2012]. J Invest Dermatol. 2012;132:1561-1572. (Decreased AQP3 expression has been implicated as a contributing factor in a range of skin diseases.)
“In small amounts urea has good water-binding and exfoliating properties for skin; in larger concentrations it can cause inflammation.”(Source: Skin Pharmacology and Applied Skin Physiology, January-February 2002, pages 44–54).
“Urea reduces the amount of water lost through skin’s epidermis.” – Skin Moisturization (a book)
One study study compared the effects of a 5% urea and ceramide NP in an emollient cream versus just the emollient cream. The subjects were all over 60 years old with dry skin. The urea + ceramide NP cream hydrated the skin to a significantly greater extent and for a longer period of time compared to the control emollient cream. Furthermore, the urea + ceramide NP cream imparted additional benefits to the structure and function of the skin barrier not exhibited by the control emollient. I would have liked to see a 5% urea cream versus a Ceramide NP cream.
If you’re in the UK and looking for urea products, check the ingredient list for “carbamide” instead. It’s the same thing.