Urea

Urea has excellent moisturising and keratolytic (exfoliating) properties. It is a substance naturally present in the body that forms part of the skin's natural moisturising factor and maintains the moisture levels it needs. It is hygroscopic, meaning it can absorb moisture from the air and retain it in the skin. Its keratolytic action makes it an excellent active ingredient for foot care, as it naturally loosens and sheds dead skin cells, leaving the skin beautifully smooth and allowing other ingredients to penetrate its layers. - relieves itching - hydrates - softens and conditions the skin - has antimicrobial properties. This substance occurs naturally in the human body as a product of protein metabolism and is produced in the skin, but cosmetics usually use a synthetic form obtained through chemical synthesis for its high purity and stability. Organic extracts from natural sources also exist, but the synthetic version is more common because of its consistent quality.

Its main mechanism of action is hydration: as a hygroscopic substance, it binds water in the skin's outermost layer and increases its elasticity. It restores the skin barrier by supporting the synthesis of ceramides and lipids, reducing transepidermal water loss. It has a pronounced keratolytic effect, exfoliating dead skin cells by breaking down the bonds between them, soothing itching caused by dryness and providing antimicrobial effects by inhibiting bacterial growth. The optimal concentration for hydration is 3-10 %, and for exfoliation 10-30 %, with higher concentrations used on thick skin on the feet.

It is particularly recommended for dry, dehydrated, sensitive and mature skin, where it provides intensive hydration and reduces roughness. At lower concentrations, it is also suitable for oily and acne-prone skin thanks to its exfoliating and antimicrobial properties, which help prevent clogged pores. It is ideal for skin with atopic dermatitis or psoriasis, or thick skin on the feet, where it moisturises and smooths without irritation.

A study published in the International Journal of Cosmetic Science (2009) demonstrated that urea at a concentration of 10 % improved hydration in drier skin by 20 % after just 1 week and by 40 % after 4 weeks of application, while also reducing itching by 35 % (Proksch et al., 2009). Another clinical study in the British Journal of Dermatology (2011) showed that 5 % urea restored the skin barrier in patients with atopic dermatitis, increasing ceramide levels by 25 % and reducing transepidermal water loss by 30 % (Grubauer et al., 2011).