Hydratants

Hydratants are ingredients or formulations designed to maintain or increase hydration of the skin and mucous membranes. In cosmetics and dermatology, they function as moisture-binding agents that help restore or preserve surface moisture in a variety of products, from creams and serums to cleansers.

Most hydratants are hygroscopic and act as humectants, drawing water from the environment or from deeper skin layers. In humid conditions they improve hydration, while in very dry air they can draw water from the skin unless an occlusive layer helps seal it.

Common hydratants include glycerin, hyaluronic acid, sorbitol, urea, propylene glycol, and sodium PCA. Some products rely on natural moisturizing factors and amino acids to attract and retain water within the stratum corneum.

Hydratants are often combined with emollients that improve skin softness and with occlusives that reduce transepidermal water loss, to provide longer-lasting hydration. They are used in moisturizers, serums, cleansers, and hair-care products, and may be tailored for dry, sensitive, or aging skin.

Safety and use: Hydratants are generally well tolerated, but high concentrations of humectants can cause stinging or irritation in sensitive individuals, especially with fragrance, alcohol, or compromised skin barriers. Climate, skin type, and product formulation should guide choice and layering.