Thank you for posting your query.Dopamine
depletion is a part if the problem in Parkinson's disease. The problem with giving external dopamine is that it does not fully go to the brain, it remains in the blood and goes to other organs as well, leading to various side effects. Also, the natural dopamine is available round the clock, which can not be achieved with external dopamine supplements.
Dr Sudhir Kumar MD DM (Neurology)
Senior Consultant Neurologist