Mmm for me Caffeine improves my strutting but I only take it on occaison because I don't want to get myself addicted to it. Maybe being addcited to it is the problem because I used to be addctied to porn and there used to be nights when I binge on watching porn and then the next day I feel like a zombie and could barely talk. I agree with people in the comments though. Not having enough sleep could worsen our stuttering.