Polyisobutene is used as a binder, film-former, and non-aqueous viscosity increasing agent in cosmetic products. As a binding agent, it helps in binding or holding together the ingredients in a cosmetic product in the compressed cake or tablet form of product, for example, a compressed powder or eye shadow. It works as a non-reactive binder, which is a very important characteristic of a binder. As a film-forming agent when applied on the hair or skin, it forms a supple, cohesive, and continuous layer. This layer/film has water-binding properties that leave a silky and smooth effect on the skin. It also functions as a viscosity increasing agent which when used increases the thickness of the solution and that gives ideal or acceptable viscosity to the product that is just right for use. It is well tolerated by the skin or quite mild on the skin.  It is used in formulations of make-up products, hair care, and skincare products.