TBJP // EAA 1KGEssential Amino Acids (EAAs) are the building blocks of protein, which the body needs for many functions, from building and maintaining bones, organs and muscle, to supporting immune function and providing energy. Theyre also critical for hormonal, enzyme, neurotransmitter and hemoglobin production. EAAsare amino acids that our bodies cant make on its own, so they have to be obtained from our diet.