L Tyrosine vs. Dextroamphetamine In a sleep deprivation study, L Tyrosine actually outperformed one of Adderall's active stimulants (dextroamphetamine) in key cognitive tests, like mathematical processing and logical reasoning, even after 30 hours with Sensing Tyrosinase Activity Encyclopedia MDPI Catalytic mechanism of the tyrosinase reaction toward the Tyr98 residue in the caddie protein PLOS Biology Oxidation of protein tyrosine or methionine residues: From the amino acid to the peptide