Humectant

A humectant is a moisturising ingredient that attracts and binds water, helping to raise the water content of the skin's outer layer. Familiar examples include glycerin, hyaluronic acid, glycols, urea, and honey.

Humectants hold water through their molecular structure, drawing moisture from the deeper skin and, in humid conditions, from the surrounding air into the stratum corneum. This helps the skin feel plumper, softer, and more supple, and can improve the look of dehydrated skin. Because they mainly bind water rather than seal it in, humectants are frequently paired with emollients and occlusives, which smooth the surface and slow water loss.

They appear across almost every product type, from toners and serums to moisturisers and masks, and suit most skin types including oily skin that dislikes heavier textures.

In very dry, low-humidity environments a humectant used alone can, in principle, draw water from deeper in the skin and leave the surface feeling tight if that water then evaporates. Layering a humectant under an emollient or occlusive helps prevent this and locks the added moisture in place.