Dextromethorphan polistirex is a time released form dxm. its safe to take as long as its the only active ingredient, however dont take in high doses as you could w/ other dxm products though cause it becomes toxic the longer it remains in your system whiich it dose cause its time released, dont go over a few hundred mg.'s. most people who trip on dxm dont trip on the time released kind cause i guess its suppose to take longer to take effect and isnt as intense as dxm hbr. id say buy a 4 ounce bottle of robitussin max strength cough.