I tried piracetam, which is structurally very similar nootropic to Oxiracetam, but I did not observe any improvement, I think after about 1 to 2 weeks of daily usage (2 tablets per day, total 2.4 g), my memory was better, which helped me a little bit with difficult exam I had that time. Also, I felt that I was thinking much more clearly and faster, but with regards to speech, no improvement at all. But everyone stutter is unique, so you can try it, it can work for you. As far as I know it does not have any adverse effects and I didn't feel any, so you only lose money for that if it will not work.