We will be monitoring 24 hour ambulatory BP and HR in subjects with PD on 3 separate visits. The first visit will be without an intervention to establish a baseline of 24 hour BP fluctuations. One week later the subject will be given either L-tyrosine (2,000 mg) with B6 (10 mg) or a sugar pill. We will monitor 24 hour BP and HR after supplementation. One week later the subject will repeat the same procedures with either supplement or placebo.