Thanks for the explanation. I would very much like feedback from anyone who tries this protocol. It takes about a week to get a significant stable effect. In my case this has been followed by a continuous gradual improvement. A word of caution: the substance in Grapefruit, furanocoumarins (20mg for a 200ml glass) must be given all the consideration you would give to any other drug. It acts to protect 50% of all drugs from being degraded by the enzyme CYP3A4 and has a long lasting effect, more than 24 hours. When taken in combination with levodopa, you will only get good results if you take it regularly. If you suddenly stop GJ, you may get what is known as a withdrawal rebound effect which shows up as severe increase in symptoms, much worse than before starting GJ. This kicks in 2 days after stopping GJ, and can be stopped by drinking a glass of GJ. As with other drugs, if you want to stop GJ, you must cut down gradually over several days