The nicotine supply that a smoker obtains from tobacco was considered a major contributing factor for establishing and continuing the smoking habit. The idea that nicotine exerts pharmacological effects which might be strived for by the smoker gains support from reports in the literature both of animal experiments and observations in humans. Hence, it was thought that smoking withdrawal would be more easy if the ex-smoker can supply himself with suitable doses of nicotine while avoiding the dangers of tar and carbon monoxide in the smoke. A chewing gum containing nicotine bound to an ion exchanger was deviced to be used for smoking withdrawal. The advantage of this preparation are that it allows administration in a convenient way of nicotine ad libitum, it precludes intoxication of the preparation if swallowed and it allows reducing the nicotine content for withdrawal purposes while keeping other properties unchanged. The preparation is now undergoing clinical trials.