We designed Dr. Scholl’s® Callus Removers with Hydrogel technology specifically for people who have calluses on their feet and want a discreet way of removing them. Why it Works:. • A callus is caused by the buildup of hard, dead skin over an area of pressure. Calluses on the feet are often caused by friction and pressure from footwear as well as abnormal patterns of walking or repetitive activities (such as in sports). • Dr. Scholl’s® Callus Removers with Hydrogel technology surround calluses and hard skin with a thin and flexible gel that provides immediate relief from painful shoe pressure and friction. Maximum strength medicated discs deliver a safe and effective callus treatment that makes callus removal simple.