Ken has been taking NADH for two years. It seems to help a little-I am not sure. He decreased his sinemet a little after he started taking it which was helpful since he cannot tolerate more tha 500mg of sinemet per day. Our neuro said we had nothing to lose by trying it since he was so bad. Now she says that she doesn't know if it works, but she has some patients that swear by it. We first tried it because Dr Birkmayer who developed it was the son of the Doctor in Vienna who helped us obtain deprenyl for Ken when it was not yet available in this country. The father was a very well reputed Parkinsons specialist and researcher who did alot of early research on l-dopa and deprenyl. So, I tended to believe the work the son was doing.Barbara Smith, CG/Ken/16