BCAAs standalone is hardly an option. Complete protein synthesis is not possible without the full essential amino acids (EAAs)! Whenever cellular levels of BCAAs (more precisely l-leucine) rise, the body is signalled to initiate protein synthesis. BCAAs play a dual role: They (more precisely l-leucine) trigger protein synthesis and also support muscle growth and prevent anti-catabolism. To be fully effective, therefore, BCAAs need the other EAAs! So, my approach is always to make sure I have enough EAAs. Then I take extra BCAAs. Then extra L-Leucine!