Amino Pro Nano Stack contains the full spectrum of essential amino acids required by the body to build muscle – including BCAAs. Amino acids are the chemical units or "building blocks" that make up proteins. Protein provides the structure for all living things. Next to water, protein makes up the greatest portion of our body weight. Proteins make up the muscles, ligaments, tendons, organs, glands, nails, hair and are essential for bone growth. Dietary amino acids are classified as "essential" or "non-essential". Essential amino acids cannot be manufactured by the body and must be supplied in the diet or ill-health results. With all 8 essential amino acids and enhanced levels of leucine and the other BCAAs (valine and isoleucine), Amino Pro Nano Stack provides your body all the amino acids it needs to build and repair muscle tissue.