Test Details: Tyrosine is the non-essential amino acid precursor for dopamine, norepinephrine and epinephrine. Low levels seen in depression, hypothyroidism, blood pressure disorders. Increased tyrosine may exacerbate migraine headaches and hyperthyroid conditions. Elevated tyrosine levels may occur due to supplementation (phenylalanine or tyrosine), heritable enzyme defects, or liver disease.