I also felt the "hangover" effect as mentioned by the others. Headache, foggy thick, I call it "doughy brain", agitation. I have a connective tissue disease, FMS following trauma from 06 auto accident plus chronic neck and back pain so the pros outweigh the cons. I take a Vicodin 750mg Flexeril and Serax cocktail at night before bed...and sometimes sleep...sucks.