[ZongMaster]

John, the answer is: it depends on your frequency of use and your body weight/body fat ratio. The more frequent, and the more fatty = longer time to purge from your blood.

Let me give you some insight into my own experience. One of my old coworkers offered me a job a few years back and failed to mention at first that there was a test that I had to pass.

After I freaked out and told my friend my concern, they let me delay my start date until I was ready. It was a good job working with some of my other friends, so I was highly motivated to NOT fail the test (it would have embarrassed both of us professionally)

There's a cutoff point, measured in nanograms (ng) that determines whether you PASS or FAIL the test. For MOST tests, this is 50ng, but I've heard that some stricter tests are calibrated to fail at 25ng. If your potential employer is not a total Nazi, they are probably paying as little as possible for your testing, so I'm guessing most places have the 50ng cutoff.

After not smoking for 15 days and drinking over a gallon of water a day, I spent $80 and went to a place called AnyLabTest and had them do a blood test on me. Before, I was smoking every day, a few times a day, but I'm also a lean, skinny former college athlete. (5'11"/155lbs)

After 15 days not smoking, my reading was 45ng. This was a little too close for comfort, so I waited longer. I didn't want to spend the $80 again until I was pretty sure I was under the limit.

After not smoking for 40 days, I had myself retested in the same manner and my reading was 19ng. At this point, I felt pretty safe about my ability to pass.

I took the employer's test and I had no problems. My rule of thumb now is that I feel "safe" for the 50ng tests after not smoking for about 3-4 weeks, i.e. 21-30 days. But do keep in mind that it's going to be a little different for everybody, depending on metabolism, frequency, etc.

If you absolutely have to pass the test, it's not a bad idea to go get your own blood test done, if you can spend the cash. Compared to the salary I ended up getting, it wasn't a bad deal. If you know you are going to fail, find any possible reason to delay the testing.

Good luck.