A chemical solution invented by Dr. Abraham Erskine in the late 1930s to early 1940s. It was designed to comprehensively enhance the overall physique of a person. It increases their strength, stamina, mental faculties, resilience, mobility, vitality and regeneration rate. The first one to be tested with it was Johann Schmidt. Because the chemicals were designed to amplify existing traits, it turned Johann into an even worse version of himself, and he even lost the skin on his face, leaving a red skull in its place. The second one to be tested was Steve Rogers, who Erskine hand picked himself after he heard Rogers' reasoning for entering the war, as well as observing his actions during training. Unlike with Schmidt, the effects of the serum worked like they were supposed to and enhanced the