For most people, it's the fear and nervousness of public speaking that's the problem (not the content, knowledge, or skills of the presenter.) This fear can hold people back (it did for me). I'm sure Toastmasters would have the same impact (and I went to a few TM meetings) but I couldn't make it work with my other commitments. Propranolol is immediate and from a personal experience, it was extremely helpful for my career, confidence, etc.