Hydroxyethyl Urea is a synthetic humectant derived from urea, widely used in cosmetics for its moisturizing and conditioning properties for both hair and skin. Known for its moisture-retaining ability and softening effects, it provides long-lasting hydration without leaving a sticky residue. Its chemical structure makes it ideal for lightweight formulations suitable for dry or dehydrated skin.

Chemical Composition and Structure

Hydroxyethyl Urea is an organic compound modified with hydroxyethyl groups, increasing its affinity for water and enhancing its moisture-holding capacity. This improves the texture and resilience of skin and hair, preventing moisture loss and promoting prolonged hydration.

Physical Properties

It appears as a clear, odorless, water-soluble liquid, easily incorporated into serums, lotions, creams, and hair care products. Its lightweight, non-sticky texture makes it suitable for a variety of cosmetic products, ensuring hydration and softness without greasiness.

Production Process

Hydroxyethyl Urea is synthesized through a chemical reaction between urea and a hydroxyethyl compound, resulting in a pure and stable product with optimal hydrating and conditioning properties.

Applications

• Medical: Known for its humectant and conditioning properties, with potential applications in treatments for dry and irritated skin.

• Cosmetics: Hydroxyethyl Urea is commonly used in skincare and haircare products for its moisturizing and conditioning abilities. It is ideal in serums, creams, lotions, and hair treatments, helping maintain moisture and improve softness without a sticky feel.

INCI Functions:

Hair conditioning agent. A significant number of ingredients with specific and targeted purposes may co-exist in hair shampoo formulations: cleansers, conditioners, thickeners, matting agents, sequestering agents, fragrances, preservatives, special additives. However, the indispensable ingredients are the cleansers and conditioners as they are necessary and sufficient for hair cleansing and manageability. The others act as commercial and non-essential auxiliaries such as: appearance, fragrance, colouring, etc. Hair conditioning agents have the task of increasing shine, manageability and volume, and reducing static electricity, especially after treatments such as colouring, ironing, waving, drying and brushing. They are, in practice, dispersants that may contain cationic surfactants, thickeners, emollients, polymers. The typology of hair conditioning agents includes: intensive conditioners, instant conditioners, thickening conditioners, drying conditioners. They can perform their task generally accompanied by other different ingredients.

Humectant. Hygroscopic compound used to minimise water loss in the skin and to prevent it from drying out by facilitating faster and greater absorption of water into the stratum corneum of the epidermis.  The epidermis is the most superficial of the three layers that make up human skin (epidermis, dermis and hypodermis) and is the layer that maintains hydration in all three layers. In turn, the epidermis is composed of five layers: horny, the most superficial, granular, spinous, shiny, and basal. Humectants have the ability to retain the water they attract from the air in the stratum corneum and have the function of moisturising the skin. They are best used before emollients, which are oil-based.

Skin conditioning agent. It is the mainstay of topical skin treatment as it has the function of restoring, increasing or improving skin tolerance to external factors, including melanocyte tolerance. The most important function of the conditioning agent is to prevent skin dehydration, but the subject is rather complex and involves emollients and humectants that can be added in the formulation.

• Industry: In the cosmetic industry, it is valued for providing non-greasy hydration, finding applications in advanced skin and hair formulations.

Environmental and Safety Considerations
Hydroxyethyl Urea is considered safe for cosmetic use and is biodegradable. As a synthetic product, it has minimal environmental impact and does not contain harmful byproducts.

Molecular Formula  C₃H₈N₂O₂

Molecular Weight  104.11 g/mol

CAS     1320-51-0    2078-71-9

UNII    MBQ7DDQ7AR

EC Number  215-304-0    640-848-4

DTXSID401315038

Nikkaji   J208.618B

Synonyms:

2-Hydroxyethylurea

Monoethanolurea

References__________________________________________________________________________

Akinsulie A, Bergfeld WF, Belsito DV, Hill RA, Klaassen CD, Liebler DC, Marks JG Jr, Shank RC, Slaga TJ, Snyder PW, Fiume M, Heldreth B. Safety Assessment of Hydroxyethyl Urea as Used in Cosmetics. Int J Toxicol. 2024 Aug;43(3_suppl):128S-134S. doi: 10.1177/10915818241237791. 

Abstract. The Expert Panel for Cosmetic Ingredient Safety (Panel) assessed the safety of Hydroxyethyl Urea, which is reported to function as a humectant and a hair and skin conditioning agent. The Panel reviewed the available data to determine the safety of this ingredient. The Panel concluded that Hydroxyethyl Urea is safe in cosmetics in the present practices of use and concentration described in the safety assessment when formulated to be non-irritating.

Esler, W. P., Das, C., & Wolfe, M. S. (2004). Probing pockets S2–S4′ of the γ-secretase active site with (hydroxyethyl) urea peptidomimetics. Bioorganic & medicinal chemistry letters, 14(8), 1935-1938.

Abstract. (Hydroxyethyl)urea peptidomimetics are potent inhibitors of γ-secretase that are accessible in a few synthetic steps. Systematic alteration of P2–P4′ revealed that the corresponding S2–S4′ active site pockets accommodate a variety of substituents, consistent with the fact that this protease cleaves a variety of single-pass membrane proteins; however, phenylalanine is not well tolerated at P2′. A compound spanning P2–P3′ was identified as a low nM inhibitor of γ-secretase activity both in cells and under cell-free conditions.