Tyrosine is a non-essential amino acid synthesized in the body from the essential amino acid phenylalanine. The typical dietary amount provided by a 3 oz portion of animal protein ranges from 0.3 g to 1 g of tyrosine. Tyrosine is the precursor amino acid from which the body makes dopamine (with vitamin B6 as a cofactor), which is then converted to norepinephrine (with vitamin C as a cofactor) and then to epinephrine (with SAMe as a cofactor).
Tyrosine competes for uptake with other large neutral amino acids, so in order to maximize absorption from the supplemented tyrosine into various tissues (such as brain, adrenals, nerves), it should be taken on an empty stomach, or two hours away from a protein-containing meal. Then it will amp up dopamine levels which is a major way of treating depression naturally. It will also help to alleviate symptoms of a chronic bad mood (aka anger) as well as addictive symptoms. It is best when combined with SAMe.