@JasonP -- I noticed this is the only thread on the forum with tyrosine in the title. I'm curious if you ever gave this a try. I just did some searching on another forum, and discovered a comprehensive post within a fairly lengthy thread. For anybody who's interested in pursuing research into this amino acid, here's a link to that post: -- @Daniel Lion
Julia Ross published a book on using amino acids for mood as certain amino acids are precursors to certain neurotransmitters and thus affect neurotransmitter deficiency. She posted a questionnaire which can help you figure out which amino acids might affect you. It certainly gives you a clue as too how your system is operating.
"L-Tyrosine influences the synthesis of a number of neurotransmitters and hormones within the brain that control stress levels. Since Tyrosine is known to increase dopamine levels in the brain, it is theorized that this is one of the mechanisms of action by which it is able to control anxiety symptoms."