You will find two popular forms of whey protein at NATURALTEIN: whey concentrate and whey isolate. Whey concentrate is the most common form of whey protein. It contains about 80% protein and is the least processed form of whey protein. Whey isolate is a more pure form of whey protein that contains about 90% protein. It is more processed than whey concentrate and people who are into muscle building or weight loss love it.