Nicorette nicotine gum pieces beside packaging. Nicorette chewing gum is a type of nicotine replacement therapy (NRT). Nicotine is an addictive drug found in cigarettes. The nicotine from the gum is absorbed into the bloodstream in measured doses from the lining of the mouth when it is chewed. Nicotine replacement therapies help to relieve the cravings felt by smokers who are trying to quit.