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thickener

Aluminum Starch Octenylsuccinate

Commonly feared, low concern·Moderate evidence

A starch derivative used to thicken sunscreen lotions and absorb excess oil; the aluminum here is bound in a starch complex, unlike the soluble aluminum salts used in antiperspirants. CIR has reviewed aluminum starch octenylsuccinate and found it safe as used in cosmetic formulations.

The myth vs the evidence

Because the name contains "aluminum," it sometimes gets lumped in with antiperspirant aluminum-salt fears, but it is a different, insoluble starch compound and the published evidence does not support treating it the same way.

Questions

Is aluminum starch octenylsuccinate like the aluminum in antiperspirants?
No. The aluminum in this ingredient is bound in a starch complex, making it insoluble and unable to be absorbed through skin. It is chemically and functionally different from the soluble aluminum salts used in antiperspirants. The Cosmetic Ingredient Review Expert Panel confirmed it is safe as used in cosmetics.
Why does this ingredient have aluminum in the name if it might be unsafe?
The INCI name describes the chemical structure, but it does not indicate hazard. This insoluble starch-bound form has been reviewed by cosmetic safety experts and found acceptable for use in topical formulations. The published evidence does not support the concern sometimes raised due to the ingredient name alone.

Products with Aluminum Starch Octenylsuccinate

References

Cosmetic information for general education, not medical advice. A verdict is a reading of the published evidence, never a guarantee for your skin: any ingredient can irritate someone, so patch test new products and see a professional if you react. Concern is graded on cited evidence, never on hazard-score lists. See how we score.