There's a lot of hype these days about protein supplements to help build up muscles. In fact, according to the President's Council on Physical Fitness and Sports, even athletes don't need extra protein to build muscles.

Muscles develop from training and exercise, and we all need a certain amount of protein to help build our muscles. But we can get what we need from a nutritious, balanced diet that includes 2-3 servings from the meat/bean/egg group (6-7 oz a day) and 2-3 servings of dairy products. Extra protein from food or protein supplements doesn't assist in muscle development. And, since protein isn't stored in the body, any excess will be either burned for energy or stored as body fat.

Source:  President's Council on Physical Fitness and Sports. Winning Nutrition for Athletes.