Rule 1 Essential Amino 9 When it comes to supporting muscle building and maintenance, these nine "essential" amino acids are aptly titled. Since they can't be synthesized within our bodies, they must be obtained through nutritional sources. Essential Amino 9 delivers 7.5g of essential amino acids in every serving, plus added electrolytes for hydration.* Informed Choice® Certified. Regularly tested for banned substances by the world class sports anti-doping lab, LGC.