not very critical at all. all protein contains amino acids. A 'complete' protein contains all the essential amino acids.
So if you eat plenty of protein, from several sources (eggs, red meat, poultry, fish, cottage cheese, as well as beans/legumes) you'll be getting plenty of the necessary aminos.
Giant IFB pros like Jay Cutler may find it useful to get extra aminos due to his shear size...but for the rest of the human race, its not critical at all to take a supplement like this.
