24 hours ought to do it, but, thr general concensus is " The sicker the better", so 48 is better. The reason for this is simple...Suboxone wont make you feel good, but it will make you fell NOT COMPLETLY HORRIBLE. The sicker you are when you take it, the more drsmatic an inprovemnt you are likely to feel. Good luck with the subs..I found it wasnt for me..dont let me scare you, though...for many many folks it is a miracle pill. I just found that some of the side effects I could not tolerate. By all means, give it a shot, just make sure your doc is accessable so that you can report and deal with any bad side effects.