• High-dose nicotine replacement therapy (NRT). Researchers are trying higher doses of NRT that match the level of nicotine used by the smoker. Individuals have been given patches of 35 milligrams (mg) to 63 mg of nicotine at a time. Studies suggest that with the higher doses, the patients’ withdrawal symptoms disappear and the cravings decrease without adverse cardiovascular side effects.

  • Clonidine. Already being used to help people deal with the withdrawal effects of a variety of different drugs, clonidine has shown to have early effectiveness in helping people to quit smoking. Subsequent studies, however, have suggested that the drug does not demonstrate statistically significant improvements in the rate of quitting. It has also two main side effects, dry mouth and the feeling of sedation, which have limited its use.

  • Special mouthwash. A nicotine-free strategy for making cigarettes taste terrible. It is similar to the drug disulfiram that makes alcohol very unpleasant for people trying to quit drinking. The mouthwash does not have an impact on withdrawal symptoms.

  • Vaccine. Researchers are testing a specific vaccine formulated to block the path of nicotine to the brain, thereby preventing the instant “high” or “rush” after smoking.