Whey Protein Isolates are the purest and most expensive form of whey protein that exists. That's why they are the first ingredients you read on the Gold Standard 100% Whey label. By using Whey Protein Isolates as the primary protein source, Optimum Nutrition are able to pack 24 grams of the purest, muscle-building protein per serving, with a lot less of the fat, cholesterol, lactose, and other stuff that you can do without. Whey Protein Isolates are the purest and most expensive form of whey protein that exists. That's why they are the first ingredients you read on the Gold Standard 100% Whey label. By using Whey Protein Isolates as the primary protein source, Optimum Nutrition are able to pack 24 grams of the purest, muscle-building protein per serving, with a lot less of the fat, cholesterol, lactose, and other stuff that you can do without.