Yeah I swear by certo....has worked for me twice in the past...get you a 32oz bottle of gatorade and mix one packet of the certo with it..you'll have to pour out some of the gatorade first cause there is quite a bit of the certo in one packet..anyway...about two hours before you test start drinking it...not fast..but finish it all before you go to test and make sure that you urinate a few times before you test..the first time that I used it my urine was clear and I passed the second time I was worried cause it was about an hour after I finished drinking it and the urine was a little yellow but I still passed. I've heard that even after you finish //it protects your system for about 4 hours...Hope this helps..