The amino acid tyrosine helps build dopamine. But the meds and the dietary intake of amino acids is not a one-to-one thing: it is not just having too little of needed amino acids that can cause domamine problems. Too, you can eat foods with tyrosine in them and your meds might not work as well, etc. Neuro chemicals and reactions are not that simple, that one can mess around with any one thing and expect a given reaction. Often, if one does not eat well, is overweight or older (such as I am, both) some of the body's systems do not work as they have in the past and that makes even more of an uncertain reaction possible with meds and/or what works, how.