It varies, deary. It effects everyone differently. I have like three bottles of left over from my two surgeries. I rarely took it. Usually it helped with the pain, but it never really made me feel loopy. Now my MIL gets some ridiculous mg and she gave me one of her pills because my side hurt so bad from my cysts and my pills didn't help any, and it completely made me feel warm and just calm.
DH has fibromyalgia and gets them for his pain. I've also taken one of his for my side and it made me sick. I felt nauseous, dizzy, and just terrible. I still felt like crap the next day. I will never take that smurf again.