The Effects of N-Acetyl-L-Tyrosine on Parkinson’s Disease
 

watch out for mao's
 

This sounds promising.
Just as an aside.... if you are experimenting,

Supplements of L-tyrosine must not be used by people on a prescription of monoamine oxidase (MAO) inhibitors; such compounds are normally used to treat clinical depression. All persons being treated for clinical depression using such compounds must avoid using L-tyrosine supplements or severely limit their consumption of all foods that contain tyrosine not doing so may induce a sudden and very dangerous rise in the blood pressure of the person.

MAO's such as Deprenyl, Selegeline, etc.