WHAT IS COMPLETE MASS™? Complete Mass™ is a calorie dense weight gainer, designed for real hard gainers. Not only does Complete Mass™ contain over 500kcal per serving, but it is crammed with multiple sources of protein & is fortified with amino acids such as & leucine. In addition, Complete Mass™ tastes so good that you'll look forward to each & every shake. Complete Mass™ focuses on quality ingredients — not just cheap sources of protein & sugar. Even