Erowid (please no one ever recomend in aswer to a question I ask on here, I read it the way some people read the bible) says DXM can cause false positives for PCP. But I think 1500 is WAY to high, my only DXM trip was at 600, and I got kinda stupid, and I handle drugs pretty well. I plan to try 1200, but I'm gonna have a sitter, something I never do.