Hydroxypropyl Starch Phosphate is a modified starch ester produced by the reaction of starch with hydroxypropyl and phosphate groups. This modification improves the physical and chemical properties of the starch. In skincare, this ingredient acts as a thickener, stabilizer, swelling agent, and viscosity modifier. It gives products a smooth, even consistency and improves their spreadability on the skin. In addition, hydroxypropyl starch phosphate reduces the sticky or greasy feel of formulations and helps retain moisture, keeping the skin hydrated. This ingredient is mild and well-tolerated, making it ideal for various skin types, including sensitive skin.(1-2)