Polyisobutene is a synthetic hydrocarbon polymer used in cosmetics as an emollient, thickener, and film-forming agent that imparts smooth texture, adhesion, and improved spreadability. It is commonly found in long-wear makeup, lip products, and sunscreens to enhance water resistance and product longevity.
| Reported effect | How often | Notes |
|---|---|---|
Skin irritation | Rare | Generally well tolerated; mild irritation occasionally reported. |
Allergic contact dermatitis | Very rare | Isolated case reports; considered low sensitizing potential. |
Comedogenicity/clogged pores | Rare | Occlusive film may contribute to congestion in acne-prone individuals. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.