Hello Ally, I can only speak for myself. I have a period of waiting untill the Sinemet kicks in. My dosage is 250mgs every eight hours. I have to rest every afternoon for about two hours. Then I am alright untill my four pm tablet time. I think that we all react differently to Sinemet. It may take longer with your father before it kicks in. Generally he should feel a great improvement in about ten minutes to a half an hour. Perhaps you will have to let his body get acclimatised to the drug. If you have serious doubts do speak to your Neuro again. Most Neuro's are very sympathetic when it comes to the right dosage. Have a nice day. Bern......Peace [log in to unmask]