Now, yes I know he is during the movie, but at the end he claims that the effects of NZT have been made permanent and he no longer needs it.
But in the follow-up TV Series Limitless S01E13, Brian doesn't know of his permanent NZT effects and hence assumes that the Senator can pause his doses for a little while to get a NZT-free blood sample. And this is indeed then further achieved and the coat is switched with a duplicate with blood not containing NZT.
So, I am confused, was Edward Morra just bluffing when he said he achieved permanent effects at the end of the movie or is there some other theory.