At any grocery store in the baking section
It is used as an anti-caking agent in powdered sugar and a thickening agent in soups.
If you are eating it-> high blood pressure, diabeties (sp), yeast infection, rashes, bladder stimulation, cracked mouth, vaginal discharge and more.
Cornstarch is or cornflour, a starch of the corn grain
cornstarch is made from corn kernels and the outer covering is removed. The center of the kernel that would become plant if the kernel were planted.