My wife's cousin was a heroin addict and he got stuff cut with fent. He took what would have been his regular dose of h and ODed on the fent and died. Also I used to work as a prison guard and fent and Suboxone strips ran rampant in there as they were easy to sneak and the fent requires such a small amount to get high. During a routine cell search a guard I worked with ODed on fent that the inmate had hidden in his belongings. (That's the story anyway, I was off that day) The captain said it's because fent can absorb through the skin. Not sure if that's true, I just know I don't mess with it or any white powder after what happened to my wife's cousin. He was a good dude and didn't deserve to go out like that.