Simply put, protein powers muscle. Klean Isolate is pure whey protein isolate, free of artificial flavoring or sweetener. We know every athlete is different: some prefer climbing to cycling, running to swimming. That's why we're leaving the flavor up to you. No matter how you take it, whether you are building or repairing muscle, training for endurance or improving your speed, Klean Isolate is up to the challenge, just like you.