Whey protein is the ultimate protein source! It has the highest biological value (BV) of any protein source, is rich in BCAAs (branched chain amino acids), and is very low in fat and lactose. Whey protein is an awesome source of protein for muscle building, fat loss, and exercise recovery. Learn more by reading the whey protein fact sheet. Muscle and Strength has low prices and cheap, same-day shipping on all whey protein supplements.