I've done a bunch of mushrooms back in the day. Did it improve my fluency? While tripping, probably yes - long term, no. I put this down to my mind wondering off during the trip thinking about all the other amazing/weird stuff that is going on rather than my speech. I've recently tried LSD for the sole purpose of entering my mind through a deep meditative state to try and uncover the reasoning behind my irrational fear of speaking. IMO, it's my fear and constant mind chatter about potential problem words that makes me stutter in the first place. Nobody is 100% fluent, why am I trying to be? Should it really matter if I fumble on a few words? These are some of the questions that I have asked myself while under the influence. The result hasn't been anything too spectacular yet, but it was an enlightening experience nonetheless that words simply can't describe. I wholeheartedly believe that my fear is irrational, yet my mind does not let me relax - just goes to show how complex the problem of stuttering is. My journey is a work in progress that's for sure. Obligatory disclaimer: LSD is a powerful drug that demands respect. Do not use it without doing your own research and make sure you're in a good state of mind.