What is urea?
Urea (or carbamide) is a compound naturally produced in the human body when the liver breaks down protein, amino acids, and ammonia. Urea is naturally found in urine, blood, and the skin, as it is a part of the natural moisturizing factor essential for skin hydration.
Being a humectant, urea not only improves the skin’s hydration levels but also the natural skin barrier (acid mantle). The acid mantle is a protective thin layer made of natural oils and amino acids. Its primary function is to keep moisture in the skin and protect the skin from bacteria and pollution. Dehydration and sensitive and dry skin are the results of the damaged acid mantle.
Brands use synthetic urea in cosmetic products. Synthetic urea is created from synthetic ammonia and carbon dioxide and can be produced as a liquid or a solid.
Urea in dermatology
As urea is a crucial part of the natural moisturizing factor, its synthetic variant is a popular ingredient in products for dry skin. It was first used for wound treatment due to its antibacterial properties. And since the second half of the 20th century, it became one of the most common ingredients for the treatment of such skin conditions as eczema, psoriasis, seborrheic dermatitis, xerosis, keratosis, ichthyoses, and other conditions, associated with dry and flaky skin.
Urea has anti-itching, anti-fungal, and anti-microbial properties, a moisturizing capacity, and a keratolytic effect. Lower doses (≤10%) of urea can be found in moisturizing creams and lotions. A higher concentration of urea (>10%) provides both hydrating and keratolytic action.
Keratolytic action means that urea dissolves proteins, such as keratin, which hold skin cells together. Urea “loosens” dead skin cells, allowing them to fall off. This is how urea provides chemical exfoliation of the skin.
And as soon as dead skin cells build-up is removed, it is easier for the moisture to get deeper into the skin. Urea is added to ointments and preparations for chronic skin conditions, as it allows other ingredients to penetrate the skin better. Being an exfoliant, urea gently removes flaking and heals cracks, which often occur for those suffering from the listed skin diseases.
Urea-containing products are also beneficial for skin complexion and are often used in anti-aging products.
Does urea have side effects?
Several studies showed that urea is non-toxic, well tolerated, and safe to use on large areas of the body.
Side effects of urea are rare, but sometimes they may include mild stinging, itching, and skin rash. These symptoms usually do not need medical attention unless they continue and become bothersome.
While urea is safe to use, you should check all ingredients on the list when choosing a product for your specific skin problem.
Opt for fragrance-free and alcohol-free products, as these ingredients dry out the skin. And make sure there are no ingredients you are allergic to.
Summary:
- Urea has an important role in regulating the skin’s barrier function.
- Urea is naturally produced in the human body. Synthetic urea made in a lab is a frequent ingredient in skincare and dermatology products.
- Urea provides a moisturizing and keratolytic effect. It works as an exfoliant on the skin.
- Urea also has anti-itching and anti-microbial effects.
- Urea is used for the treatment of such skin conditions as eczema, psoriasis, seborrheic dermatitis, xerosis, keratosis, and ichthyoses.
- Urea is well tolerated and has few side effects.
