As you may know, BCAAs include the three essential amino acids: leucine, isoleucine and valine. The 2:1:1 ratio refers to the proportion of leucine, isoleucine and valine in the formula. In our case, our BCAA Amino offers you all three essential amino acids in a 2:1:1 ratio, meaning you get 2 parts leucine to one part isoleucine and one part valine per shake. The BCAA ratio of 2:1:1 is proven to be best suited for building and maintaining muscle mass.