i dont trust any of that shit...some places test for water levels some test for creatine levels ..u have to know the place u go to...the best way to go is be clean...and if u cant do that..try strip from GNC $50 cleans u out for good not a blocker....the day before ur test..kind of expensive..really nasty....but works veerytime.....only if u have a one time test..ive done it for proabtion