What it is
This ingredient is a polymer in which acrylate chains are grafted onto a starch backbone, combining water-absorbing capacity with the soft feel of starch. It thickens water-based phases and can absorb excess oils and moisture, contributing to a powdery, dry-touch finish. In sunscreens it is often used to reduce greasiness and improve the sensory feel of the applied layer.
Safety & warnings
This is a high-molecular-weight polymer that is not appreciably absorbed and is generally well tolerated with low irritation potential in cosmetic use.
Origin & sourcing
Semi-synthetic; made by grafting synthetic acrylate polymer onto plant-derived starch.
Questions everyone asks
What is sodium polyacrylate starch used for?
It thickens formulas and absorbs excess oil and moisture, helping create a lightweight, dry-touch finish in sunscreens and lotions.
Does it leave a greasy feel?
No. It is often chosen specifically to reduce greasiness and give a soft, powdery finish to the skin.