The recent discussion about the half life of L-dopa brings to mind the following: I take generic sinemet (25/100) 30 minutes before I eat. After 30 minutes I can tell that the med is working and I am "on." I eat after 30 minutes and yet I continue my on period for 2 1/2 hours. Does the L-dopa get dumped into the brain all at once and remain there to be "used up" during the next 2 1/2 hours or does it gradually enter the brain as it circulates in the bloodstream? If it remainsin the bloodstream why doesn't the food protein interfer with it's absorbtion? If I take the sinemet within an hour AFTER eating it NEVER seems to work and I remain in an "off" state until about 4-5 hours after eating and then when I take the medicine it will work within 30 minutes.