What Is L-Tyrosine? L-Tyrosine naturally-occurring amino acid that is essential to both physical and mental functions. It is the precursor for dopamine, adrenaline, and norepinephrine, three of the most important neurotransmitters. Dopamine is associated with reward and pleasure and plays an important role in mood, motivation, and cognition; adrenaline and norepinephrine are the hormones behind … Continue reading L-Tyrosine