L-Tyrosine can enhance dopamine transmission across multiple brain pathways.

“If you were to amplify dopamine levels, for instance, by taking the amino acid precursor to dopamine L-Tyrosine, something that I occasionally do to enhance dopamine levels for sake of work or energy, 500 milligrams or 1,000 milligrams even of L-Tyrosine. Sometimes I'll combine that with other things like Alpha-GPC. It's going to enhance dopamine transmission in the nigrostriatal pathway, the mesocortical pathway, but also in the mesolimbic pathway, and also, for that matter in the tuberoinfundibular pathway associated with the pituitary.”