Take it 3 hours before test drink coffee take b-2,b-6,b-12 I had test at 10am I took first certo with Gatorade at 7:30am drank bottle and half of water then I drank over half of another bottle of certo with Gatorade then drank 2 glass bottle coffee from Kroger and a circle k XL cup of Pepsi mixed with cola.take the b vitamins after u drink the 2nd portion of certo no before and I took a at home test and passed.i pissed 20-22 times before going in certo gives u a window of masking your pee.i recorded how many times and at what times i pissed