**propanolol** on itself will not help alot, at first you may have placebo effect but as you use it placebo effect will go down and you will go back to your normal fluency rate.. that is because **propanolol** doesnot relieve anxiety it just slows your heartrate down and kind of reduce secondary symptoms of anxiety... if you want to improve you stuttering you have to pair propanalol with SSRI or anti-anxiety medication, only then it will work... it will reduce your blocks/stutter from anywhere between 60 to 80 to 90% , in order to achieve 100% you have to do speech therapy (not talking about techniques) but therapy that will correct your secondary bad behaviours of speech that comes because of stuttering like stopping breath/phonation/pushing hard and little bit CBT/REBT/NLP to change your beliefs/perceptions and intentions.. you can have a look at thread that i created r/StutterMedication