The Worlds #1 Protein Brand brings you Performance Isolate - a single source, ultra-filtered protein made using only whey protein isolates.Ultra Filtered For Exceptional Purity Performance Isolate is a single source, ultra-filtered protein made using only whey protein isolates. Starting with the highest quality whey protein, the raw material undergoes a series of sophisticated separation processes to remove excess fat, cholesterol, sugars and other materials until all that remains is the purest form of protein.