That l-dopa represents a major advance in Parkinson treatment should not hide that a number of problems remain unanswered: on-off effects, transient improvements... Based on the beneficial effects of l-tyrosine in dopamine dependent depressions and narcolepsy, five naive patients diagnosed after sleep polygraphy criteria and five l-dopa and/or dopamine agonist treated patients were prescribed l-tyrosine as a long-term treatment. For some patients, 3 years of L-tyrosine treatment was followed by better clinical results and many fewer side effects than with L-DOPA or dopamine agonists. However, the theoretical long-term sparing neurons potentiality of approach requires further studies.