From GNC, the solution USED to be Goldenseal extract supplements. Now-a-days however, some companies, especially government agencies, also test for this herb and other "popular herbal cleansers" in the urine to see IF one has been trying to clean something "suspicious" out. If you test positive for any of these cleansing agents you may be disqualified for some "technical yet unequivocal" excuse. Be careful with the cleaners is my message to you. If you're taking hydro or something stronger, and have a script for it, I'd bring it with you (or the bottle--at the minimum) to the pee test so when it shows up in your urine it won't make you look bad or suspicious.