A powdery starch derived from various species of corn. It is commonly used as a thickening agent in foods. In skin powders and cosmetics, it serves as an anti-caking agent and as a dry lubricant. It can also soothe itchy or irritated skin.

Cornstarch is a safe additive, especially when applied directly to the skin. It can be dangerous for people with corn allergies, however. Allergy symptoms include asthma attacks, swelling, and in extreme cases, anaphylaxis.