Essential amino acids (EAAs) are a specific form of amino acids which the body cannot produce on its own and therefore either needs to come from our diet or an EAA supplement. The beauty of Mammoth EAA9 is that it can truly be used any time of day. This includes, pre-workout, intra-workout, post-workout, and even during the day (such as between meals) if you wish to remain in an anabolic state and provide your muscles with a constant supply of amino acids.