Introduction
Moisturizing, emollient and softening, a cream with urea promotes skin exfoliation making the skin shiny, soft and smooth.
By promoting the restoration of natural skin hydration, creams with urea are especially useful for softening and elasticising extremely dry, thickened and chapped skin. More generally, urea creams are surprisingly effective in reducing signs and symptoms related to skin hyperkeratinization. These cosmetic products can be prepared with urea dosages ranging from 3% to 40%, depending on the ailment to be remedied.
Urea: chemical analysis
Identified by the molecular formula CO (NH2) 2, urea is an organic substance otherwise known as carbamide. Under normal conditions, urea comes in the form of a white, crystalline powder.
The molecule, very soluble in water and glycerol, solubilizes quite well even in alcohol.
Urea is naturally present in the superficial layers of the skin; in particular, the molecule is a natural component of NMF (acronym for Natural Moisturizing Factor, the natural moisturizing factor of the epidermis). Not surprisingly, creams formulated with urea are indicated to reintegrate the NMF, while increasing the water content in the stratum corneum.
Effect on the skin
Thanks to its functional properties, urea is widely used in the cosmetic field for the creation of creams, lotions or gels to treat highly dehydrated and thickened skin.
Specifically, urea creams possess the following properties:
- Keratolytic-exfoliating properties → the application of creams with urea favors the removal of dead cells from the surface of the skin
- Moisturizing and softening properties → by effectively retaining water molecules, urea creams deeply moisturize the skin, softening the skin layer and promoting the healing of small skin cracks
After applying the product to the skin in the form of a cream, urea easily solubilizes in the water component of the skin's hydrolipidic film: in doing so, the molecule penetrates deeply into the corneocytes and, dispersing among the keratin fibers, encourages the moisturizing effect. and softener on the skin.
- Emollient and calming properties → urea creams are used to repair and regenerate the skin in the immediate post-depilation
To enhance its therapeutic-like beneficial effect, a urea cream can be enriched with natural active ingredients with an emollient, moisturizing, nourishing and healing action. The most used natural active ingredients for this purpose are:
- Aloe vera gel, Chamomile and calendula → soothing properties
- Jojoba oil, Shea butter, sweet almond oil, acai oil → nourishing properties
- Hypericum → healing properties, suitable for sensitive, fragile and reddened skin
- Propolis → healing, disinfectant properties
Indications
We have seen that creams with urea are widely used to hydrate the skin in depth, effectively counteracting skin dehydration and cracking.
It should be borne in mind, however, that not all urea creams are the same: these dermo-cosmetic preparations differ, in fact, for the concentration of active ingredient present in them. In cosmetics, urea is used at concentrations varying from a minimum 3% to a maximum of 40%. At higher concentrations, urea is generally used to prepare medicated creams for the treatment of different dermal ailments.
The table shows the most common uses of creams with urea, divided according to the concentration of active ingredient.
Cosmetic / therapeutic uses of urea cream
- Humectant
- Moisturizer for dry foot skin
- Repairing (indicated for post-depilation)
10-20%
- Exfoliating-keratolytic → Indicated for the treatment of ichthyosis (severe keratinization disorder whose main symptom is dry skin)
- Regenerating / repairing → for the treatment of onychomycosis and brittle nails
20-40%
- Exfoliating, repairing and softening → used for the treatment of psoriasis, eczema, xerosis and to remove calluses and calluses
>40%
- Indicated for the treatment of atopic dermatitis
Application
For the treatment of corns, calluses, dry / cracked skin and hyperkeratosis in general, it is recommended to apply the cream with urea 2 or more times a day (as indicated by the doctor) on the surface of the skin. The massage is an integral part of the treatment: to facilitate the absorption of the product more quickly, it is advisable to massage the dehydrated skin for a long time. In subjects predisposed to cutaneous xerosis and calluses of the feet, the advice is to use the urea cream in continuous way: the regular and constant application of the product on the skin provides a pleasant feeling of well-being, while at the same time preventing irritation from rubbing.
To give quicker relief to dry and cracked skin on the feet, a warm and invigorating footbath is recommended before treatment with urea cream.
Side effects
Urea creams are well tolerated by all skin types; therefore, these formulations can be considered safe. However, immediately after applying the cream, some patients with particularly sensitive skin experience mild and temporary side effects, such as:
- Slight skin irritation
- Temporary burning and tingling sensation
- Itching
- Allergic reaction (rash, hives, swelling of the face, mouth and tongue): extreme and very rare cases
Contraindications and recommendations
The urea cream must not be applied to the skin in case of hypersensitivity - ascertained or presumed - to any excipient or active ingredient listed on the label.
While not always requiring a medical prescription, urea creams should only be applied to the skin with the advice of a doctor or an expert in the field.
Before using urea creams, it is recommended to inform the doctor in case of pregnancy, breastfeeding, allergies and any pharmacological therapies in progress. Some drugs can in fact interact with urea creams causing even serious side effects.
