A whey protein isolate (often whey isolate) is a dietary supplement and food ingredient created by separating components from whey. Whey is a milk by-product of the cheese-making process. Whey can be processed to yield whey protein in three forms: whey isolate, whey concentrate, or whey hydrolysate. The difference between the whey protein forms is the composition of the product, particularly the protein content. Whey isolates contain the highest amount of protein and can be virtually lactose-free, carbohydrate-free, fat-free, and cholesterol-free.