Mega pro nutrition has egg amino acids as a supplement to building lean body mass. The protein efficiency ratio (PER) rates the quality of a protein by the number and proportion of the essential amino acids it contains. Eggs have the highest ranking on the PER scale. Eggs contain all eight essential amino acids in a proportion regarded as the most readily assimilable and usable combination of all naturally occurring amino acids. Eggs are the standard by which all other protein sources are rated for their ability to assimilate.