It did seem to help quite a bit. However I took the phenibut a little too long before the prop. So I only felt the benefits for the first portion of the experience. What else is a good drug to combat propyilhexedrine's nasty side effects? Towards the tail end of the experience my blood pressure went through the roof. My ears were ringing and I nearly passed out upon standing up. Plus my heart rate steadily increased until it reached the point where I began to get concerned. I took 1 MG Xanax (zero tolerance) and it seemed to have little to no effect.