<s>[INST] How long does Contine from tobacco stay in your system. My fiancé said he quite chewing tobacco also two weeks ago but keeps coming up a hard positive within seconds for contine on the urine tests I bought. I tried it since he thought it was bs and it came up negative right away. I feel he is lying to me about quitting. Everywhere I read it says pretty much the same 7 to 10 days max. It s been 16 days according to him. Please help. [/INST] Conitine stays in blood after chewing/smoking or any other form for around 48-72 hours depending upon the metabolism of the conitine in body. Many passive smokers also have low levels of conitine in blood. See the cut of concentration on the kit you are using. </s>