Cornstarch is a carbohydrate extracted from the endosperm of corn. (the endosperm is the part of a seed which acts as a food store for the developing plant embryo, usually containing starch with protein and other nutrients.).  It is used both in the culinary field and in the skincare industry.  

Cornstarch can be used in body powders for its moisture absorbing properties.  It's anti-inflammatory properties help to soothe rashes, burns and itching.