. My partner and I have been using meph for about a year now. …. Last weekend we polished off 12g between us over the weekend…we have never experienced any anxiety or negative effects as a result of using meph. However last weekend we did end up in casualty dept when i dislocated my jaw from all the clenching etc that i tend to do….the up shot was getting a shot of pethedine when doc realigned by jaw !