C30-45 Alkyldimethylsilyl Polypropylsilsesquioxane

C30-45 Alkyldimethylsilyl Polypropylsilsesquioxane is a synthetic silicone polymer derived from silica and hydrocarbon chains. It belongs to a class of ingredients known as silicones, which are widely used in skincare and cosmetic formulations for their film-forming properties.This ingredient works by depositing a thin, continuous film across the skin's surface. It is not absorbed into the skin, but rather remains on the outer layers, where it creates a protective barrier and smoothing effect.

This silicone polymer chains together to form a flexible, continuous film when applied to skin. The film sits on the outer surface layer and does not penetrate deeply into the epidermis. Its structure allows it to conform to the skin's contours, filling in micro-irregularities and creating a smoother topography.The protective barrier it creates can help reduce transepidermal water loss (TEWL) and buffer the skin against environmental irritants, whilst its breathability means it does not trap sweat or create an occlusive seal that could promote bacterial growth.

This ingredient is typically found in moisturisers, primers, serums, and protective creams. It works well when layered with other hydrating or treatment ingredients, as it forms a surface layer without interfering with the efficacy of actives beneath it. Apply to clean, damp skin and allow it to set before applying makeup or additional products.

Generally well-tolerated across all skin types. It is non-comedogenic and does not bioaccumulate in skin. Individuals with documented silicone sensitivity are rare, but should avoid this ingredient or perform a patch test first.