Good supplements for building muscle include whey protein powder and casein protein powder. Both supplements provide the body with vitamins and nutrients that promote muscle formation.
Whey protein, which comes from milk, is high in branched-chain amino acids and stimulates protein synthesis. The substance prompts the muscles to start building at a rapid pace. Whey also promotes the digestion of fat, so the mass the body gains will be muscle alone.
Casein is a milk protein as well. It is slowly digested by the body and promotes muscle protein synthesis. Casein is best taken at bedtime, since it prevents catabolism.