Categories

Moisturizers

The cosmetic category called "moisturisers" comprises products whose function is to maintain skin hydration and surface comfort. The cosmetic literature usually describes them by reference to three functional ingredient classes — humectants, emollients and occlusives — that often coexist in a single formulation.

Regulatory class

Moisturisers are cosmetic products under Article 2 of Regulation (EC) No 1223/2009, falling within the function of "keeping in good condition". A subset of products marketed in connection with dry-skin conditions (atopic-prone skin, very dry skin) are sold as cosmetics; a separate set, often described as "emollient creams" or "barrier creams", are placed on the market as medical devices under the Medical Device Regulation, particularly where they make claims to a defined medical purpose such as the prevention of recurrence of atopic dermatitis flares. The regulatory class follows from intended purpose, not from the colloquial product name.

The three functional classes

• Humectants — substances that attract and bind water in the upper stratum corneum. Examples include glycerin, sodium hyaluronate, urea, propylene glycol, butylene glycol, sodium PCA, betaine.
• Emollients — substances that fill the inter-corneocyte spaces and improve skin surface smoothness. Examples include vegetable oils, esters (isopropyl myristate, cetyl ethylhexanoate), squalane, fatty alcohols (cetyl alcohol, stearyl alcohol).
• Occlusives — substances that form a hydrophobic film on the skin surface and reduce transepidermal water loss. Examples include petrolatum, mineral oil, dimethicone, beeswax (cera alba), lanolin.

A finished moisturiser typically combines all three classes in an emulsion or oil-based vehicle. The proportion of each, together with the choice of specific ingredients, determines the sensorial profile (light, rich, greasy) and the suitability for different skin types.

Vehicle types

• Oil-in-water emulsions (O/W) — lighter, faster-absorbing; most facial moisturisers.
• Water-in-oil emulsions (W/O) — heavier, more occlusive; common in cold-weather body and hand creams.
• Anhydrous formulations — balms, ointments, oils; high occlusion, no preservative load needed against bacterial growth in water.
• Gels — water-based with hydrophilic polymers; minimal oils; light sensorial profile.

Atopic-prone skin and the cosmetic/device boundary

"Atopic-prone skin" is a cosmetic descriptor used to position certain moisturisers; it refers in marketing terms to skin that is dry, sensitive and prone to the discomfort associated with atopic conditions. Cosmetic products positioned for atopic-prone skin must comply with the general cosmetic claims rules: they may not present themselves as treating or curing atopic dermatitis (which is a disease and would require a medicinal product). Products that do make such claims fall outside cosmetic law.

Some emollient products are placed on the market as medical devices under the MDR rather than as cosmetics. These devices typically rely on a physical mode of action — building a protective film on the skin surface — to support a defined intended purpose. They bear the CE mark and the conformity of their conformity-assessment route can be checked from the labelling and the notified-body number where applicable.

What labels do and do not tell you

The INCI list identifies the ingredients in descending order of weight to 1%; cross-referencing the INCI list with the three functional classes above gives a sense of where the formulation sits on the humectant–emollient–occlusive axis. Performance terms ("intensive", "ultra-rich", "24-hour hydration") are not regulated cosmetic categories; claims used must comply with Regulation 655/2013. Period-after-opening symbols, batch codes and the responsible person's details are mandatory under Article 19 of Regulation 1223/2009.

Last reviewed: May 2026.