While Meth isn't good for you by any means I still think that the worst effects are caused by the impurities left in poorly cooked/washed speed. When I was using it I got to the point where I wouldn't buy anything that wasn't white/ off white. If I used brown or tan meth I felt like shit, my joints and bones ached, and would get horrible painful acne and deep tissue boils(maybe cysts) on my chest and back.