Aluminum Starch Octenylsuccinate

Benefits
UV Protection

What is Aluminum Starch Octenylsuccinate?

Aluminum Starch Octenylsuccinate is a synthetic derivative of natural starch, typically sourced from corn, chemically altered through esterification with octenylsuccinic anhydride and complexed with aluminum ions. This modification renders it hydrophobic, enabling selective absorption of oils and sebum over water. Commonly found in powder-based cosmetics like foundations, blushes, and dry shampoos, as well as emulsions and sunscreens. In formulations, it functions by swelling upon contact with skin oils, trapping sebum to impart a dry, velvety texture, prevent caking in powders, and stabilize viscosity for smoother application. Its fine particle size enhances spreadability and optical diffusion for a blurred appearance. Widely used in oil-control products to maintain freshness throughout wear.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 1-2 View on EWG →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Absorbent
Absorbs water and/or sebum to reduce greasiness and shine, improve dry touch, and help keep powders and emulsions feeling lighter on skin.
Anticaking agent
Prevents powders from clumping by reducing moisture pickup and improving flow, keeping loose and pressed powders uniform during storage and use.
Viscosity controlling agent
Adjusts thickness to the desired level for stability and usability, improving dispensing, suspension, and texture across many formulation types.

Benefits

Absorbs sebum to minimize shine and greasiness on skin.

Provides a smooth, dry-touch feel in powders and creams.

Offers light UV scattering for added sun defense.

Who It's For

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

Who May Benefit Who Should Avoid
People with oily or combination skin seeking matte effects.
Individuals sensitive to aluminum compounds.
Those preferring non-comedogenic ingredients in makeup.
Those with starch allergies, though rare in modified forms.
Users wanting lightweight, shine-free formulations.
People preferring aluminum-free products.
—
Users avoiding modified starches altogether.

Safety Notes

  • Rated low hazard by EWG with scores of 1-2.
  • Deemed safe for cosmetic use by expert reviews.

Frequently Asked Questions about Aluminum Starch Octenylsuccinate

What does it do in skincare?

Absorbs oils for shine control and smooth texture.

Is it safe for daily use?

Yes, low hazard rating supports cosmetic safety.

Does it help with oily skin?

Yes, targets sebum for a matte finish.