What it is
Cornstarch (Zea Mays) is a silky and powdery starch obtained from the dried center of the corn kernel.
What it does
Cornstarch is an absorbent. It is sometimes used in cosmetics instead of talc because it absorbs more. However, it cakes easier.
Cornstarch is also a thickening agent, can decrease greasiness and improve the feel of a product.
Cornstarch can cause allergic reactions.
In addition, when it turns moist, it can promote bacterial growth in pores.