Natural Whey Proteins, Fitness Proteins and Supplements of Proteins I take a protein drink every day which has 40 grams of protien

This proves that milk contains only about 1% whey protein. So to equal 40 g of proteins with whey proteins you will need to drink many liters of milk or whey water in a day which is not possible. If you are interested in replacing your proteins with whey proteins then concentrated whey protein powder (whey protein isolate) is often a good idea.

Whey protein is a high quality, pure and natural form of protein derived from cow’s milk.