Urea in Dermatology: A Review of its Emollient, Moisturizing, Keratolytic, Skin Barrier Enhancing and Antimicrobial Properties

Abstract

Urea is a hygroscopic molecule (capable of absorbing water) present in the epidermis as a component of the natural moisturizing factor (NMF) and is essential for the adequate hydration and integrity of the stratum corneum. Urea improves skin barrier function including antimicrobial defense by regulating gene expression in keratinocytes relevant for their differentiation and antimicrobial peptide production. It also plays a fundamental role in regulating keratinocyte proliferation. One of the first uses of urea in modern medicine was the topical treatment of wounds due to its proteolytic and antibacterial properties. At present, urea is widely used in dermatology to improve skin barrier function and as one of the most common moisturizers and keratolytic agents. Urea-containing formulations are available in diverse formulations and concentrations. Multiple clinical trials on the use of ureacontaining formulations have shown significant clinical improvement in many of the dermatosis presenting with scaly and dry skin such as atopic dermatitis, ichthyosis, xerosis, seborrheic dermatitis and psoriasis, among others. Furthermore, urea can increase skin penetration and optimize the action of topical drugs. Ureabased products are well tolerated; their side effects are mild and are more frequent at high concentration. Here, we present a review of the use of urea in dermatology, discussing its mechanism of action, safety profile and frequent indications.

Exploring strain diversity of dominant human skin bacterial species using single-cell genome sequencing

“…Regarding the genes on the plasmids; allantoin, an intermediate product of the metabolic pathway encoded in the M. osloensis plasmid, is a substance of interest specifically for its antioxidant and anti-inflammatory properties, antibacterial effects, and wound healing in the skin (Paller et al, 2017). In addition, the end product, urea, is considered a natural moisturizing factor and is important for skin hydration (Piquero-Casals et al, 2021). The nar operon encodes a family of nitrogen reductases that reduce nitrate in the bacterial membrane.…”

Skin Barrier Enhancing Alternative Preservation Strategy of O/W Emulsions by Water Activity Reduction with Natural Multifunctional Ingredients

“…As a w -lowering solutes, Alber et al used glycerol or urea at a concentration of 20%. However, in personal care formulations, these humectants are usually used at lower concentrations since glycerol affects sensory properties and urea has a keratolytic effect [34]. This could be the reason why, to our knowledge, there are no cosmetics on the market that are based on, or advertised as, formulations that are highly reduced in water activity.…”

Urea-Based Patches with Controlled Release for Potential Atopic Dermatitis Treatment

“…Polymers soluble in water have a short degradation time, which is followed by burst drug release [ 22 ]. Urea is broadly used in dermatology, as it improves the skin barrier and acts as a moisturizer and keratolytic agent [ 23 ]. It is highly water-soluble, and incorporated in 4–10% formulations to moisturize skin; thus it is often applied in AD treatment [ 24 ].…”