dude clen has like a 3 cay clearance, but on a standard work test they wont screen for clen. the risk is that clen could be "cross reactive" meaning that it could show up as something that is tested for like methamphetamine, foer example marijuana is cross reactive to aspirin yes aspirin, the chance is small but it does exist especially if u dont know for sure that ur clen is clean meaning if u order clen in the liquid form pssibly there could be other chemicals in it in trace amounts, i would really superhydrate ur self so ur pissing almost distilled water and they cant get aread on the specimen at all, than u run the risk of them re-testing u after u thought the "heat" was off and started doing clen again or somethin else but bottom line aas and the likes are too expensive to test for unless ur a pro or collegiant athlete or in the olys, if ur worried but the book URINE TROUBLE but i think by now it is slightly outdated i failed an ncaa test for weed and it ruined my athletic carreer and almost my life