Kathy; Back in 1984 when I was originally diagnosed, I became very nauseous on the 10/100 Sinemet, although I did seem to feel better generally. When my dose was raised to 25/100 , the nausea abated and finally disappeared. Some years after (3 or 4), I read in the medical literature, that the carbidopa is the ingredient that eases the nausea and makes the levodopa effective with less side effects. Supposedly it takes 75 carbidopa per day to do the trick. That probably varies according to the individual. I wish I could cite the reference, but those were my pre-computer days. mehmois @aol.com Mary Manfredi