I had my life insurance changed about a year ago and I had a good discussion with the nurse who came to do my exam. I am a non-smoker/non-drinker and in great shape so I wasn't concerned about a thing. But, I asked him alot of questions about the process and the tests that would be done on my blood, and urine.
I asked for a copy of the report and they did tons of tests. Nicotine was one of them. The nurse told me that if any of the tests appeared manipulated, then they could request hair, which I guess holds a longer record of your health? I guess I am probably not helping too much, but if you take something to try and mask the nicotine, based on what I was told it might send off warning signals and the underwriter may request hair.
I have never been a smoker, but I guess it is impossible to quit for a few weeks? Maybe then the nicotine will be flushed out of your system.