Dopa Administration

Some articles on dopa:

Dopar - Therapeutic Use
... -DOPA crosses the protective blood–brain barrier, whereas dopamine itself cannot ... Thus, -DOPA is used to increase dopamine concentrations in the treatment of Parkinson's disease and dopamine-responsive dystonia ... Once -DOPA has entered the central nervous system, it is converted into dopamine by the enzyme aromatic L-amino acid decarboxylase, also known as DOPA decarboxylase (DDC) ...