Like ive said in other forums... a lot of ppl are messing up because they havent heard of niacin. Very inexpensive and sure to work. Ive been a smoker for 3 years now... multiple jobs during that time, even military, ill smoke all the way up till the day before the screening, pop 3-5 niacin and be completly fine. Other than turnin very red and occasional itching, its a small price to pay for a clean screen. The best method by far.