What it is
Hydroxypropyl starch is a starch that has been chemically modified with hydroxypropyl groups to improve its stability and performance in formulations. In sunscreens and other skincare it helps control viscosity, bind ingredients together, and refine skin feel, sometimes contributing a soft or powdery finish. It is commonly used to reduce greasiness and improve the sensory experience of creams and lotions.
Safety & warnings
Modified starches like this are generally well tolerated and are widely used as functional excipients with a low expectation of irritation. It is not a recognized fragrance allergen.
Origin & sourcing
Derived from plant starch (commonly corn, potato, or other crops) that is then chemically modified with hydroxypropyl groups.
Questions everyone asks
What does hydroxypropyl starch do in a sunscreen?
It mainly works as a thickener and texture agent, helping control viscosity and improve skin feel, including reducing a greasy or heavy sensation.
Is it natural?
It starts from a natural plant starch but is chemically modified, so it is best described as a plant-derived, modified ingredient.