According to the label on my package of L-tyrosine, this amino-acid increases the production of dopamine in the brain, and may also increase metabolic rate due to an increase in thyroid hormone T4 (or was it T3?) production. First of all, is this true? I haven't got a clue of what tyrosine does except being raw material for the catecholamines, and thats great in terms of fat-loss.
Second, if tyrosine increases the production of dopamine in the brain, what happends if I stop supplementing with tyrosine? Does the dopamine-production adjust itself to the intake of tyrosine over time, so that the levels decrease once supplementing tyrosine intake is stopped?