Optimum Nutrition's Essential Amino Energy combines an optimal ratio of rapidly absorbed free form amino acids- including BCAAs and arginine - as well as beta alanine and N.O. boosting ingredients to help you reach your next level. And at just 29 calories per serving it makes a big impression without denting your diet. Mix up Essential Amino Energy by itself - or stack it with your favourite powdered supplements. Optimum Nutrition's Essential Amino Energy combines an optimal ratio of rapidly absorbed free form amino acids- including BCAAs and arginine - as well as beta alanine and N.O. boosting ingredients to help you reach your next level. And at just 29 calories per serving it makes a big impression without denting your diet. Mix up Essential Amino Energy by itself - or stack it with your favourite powdered supplements.