Polyisobutene

What is Polyisobutene?

Polyisobutene is a clear, colorless, viscous synthetic polymer produced through the polymerization of isobutylene, a petroleum-derived gas. In cosmetics, it belongs to the category of hydrocarbon resins and is commonly found in makeup products like lipsticks, mascaras, and eyeliners, as well as hair styling aids and sunscreens. It functions by creating a flexible, continuous film on the skin or hair surface, which enhances product adherence, provides water resistance, and boosts shine or hold. As a binder, it helps compact solid ingredients into durable forms such as pressed powders or sticks, improving structural integrity. Its viscosity-controlling properties allow formulators to achieve the ideal thickness for smooth application, better suspension of particles, and overall product stability, making it versatile across various formulation types without altering skin feel significantly.

Comedogenic Rating 0/5 Low risk of clogging pores

EWG Safety Rating 1 View on EWG →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Binder

Helps hold solid ingredients together to form cohesive tablets, compacts, or sticks, improving pressability, integrity, and wear of the finished product.

Film former

Creates a continuous film on skin or hair to improve wear, water resistance, transfer resistance, shine, or hold in sunscreens, makeup, and styling products.

Viscosity controlling agent

Adjusts thickness to the desired level for stability and usability, improving dispensing, suspension, and texture across many formulation types.

Binding

Provides cohesion by helping ingredients stick together, improving the strength and integrity of pressed powders, tablets, or solid bars.

Benefits

Enhances product longevity and water resistance through film-forming action.

Improves texture and ease of application by controlling viscosity.

Supports compact structure in solids like powders and sticks for better durability.

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit	Who Should Avoid
Individuals seeking long-wearing makeup formulations.	People with rare sensitivities to synthetic polymers.
Users preferring smooth, stable textures in creams and lotions.	Those preferring entirely natural or plant-based ingredients.
Those with acne-prone skin due to its non-comedogenic nature.	Individuals experiencing irritation from film-forming agents, though uncommon.

Safety Notes

Considered safe for cosmetic use by regulatory reviews with low hazard ratings.
Shows minimal irritation potential in standard testing.

Frequently Asked Questions about Polyisobutene

Is polyisobutene safe for skin?

Yes, it is regarded as safe with low hazard ratings from authoritative cosmetic safety assessments.

Does polyisobutene cause acne?

No, it carries a comedogenic rating of 0, making it suitable for acne-prone skin.

What products contain polyisobutene?

Commonly used in lipsticks, mascaras, pressed powders, sunscreens, and hair styling products.