I was extremely skeptical. I've been smoking for 2 years, 4 days a week. I had to get a urine drug screen that also check pH, specific gravity, and temp. I failed one before from just taking the B vitamin, my urine was marked diluted. Took this. As directed. Wanted to better the odds to I chewed those 3 big chewables. A drank Gatorade when plugging my nose. Lol. Took the test. Nervous for almost 2 days thinking that I failed. Long and behold I passed! Even with all the strict checking for dilution or tempering. This is worth every dollar!