Astringent

Astringents produce a temporary tightening sensation and can leave skin feeling drier at the surface. In personal-care products they may be included for that toning feel or to help manage moisture. The aluminum salts used in antiperspirants also have astringent qualities, which is part of how they interact with the skin. The term describes a physical effect rather than a specific single ingredient. Several different substances can act as astringents, so the label word describes what they do, not one chemical. The tightening feel is separate from any effect on how much a person actually sweats. Witch hazel and certain plant extracts are familiar examples. The sensation is often described as a slight pull or firming of the skin. Because it is an effect rather than one compound, many products can be called astringent.

A tightening, slightly dry feeling on the skin after applying a product reflects an astringent effect. That sensation on its own does not confirm the product reduces sweat, since the astringent feel and true wetness reduction are not the same thing. A toner that leaves the face feeling taut is producing the same astringent sensation in a skincare context.

Aluminum-based antiperspirant actives have astringent properties, and the effect contrasts with humectants that hold moisture in the skin.