Two hundred and ten subjects entered a trial to test the use of a chewing gum containing nicotine as an aid to stopping smoking. They were divided into three groups: nicotine chewing gum, placebo chewing gum, and control. The trial was double blind between the two chewing gum groups. After 1 month the percentage of confirmed non-smokers in the nicotine gum group was 34%, in placebo chewing gum group 37% and the control group 24%. By 6 months most of the non-smokers had relapsed, but the nicotine gum group (23%) was more successful than the placebo (5% or the control group (14%).