Nicotine gum is chewing gum specially formulated with nicotine to help reduce your withdrawal symptoms to help you kick your smoking habit. It's a form of nicotine replacement that's available in 2 mg and 4 mg for effective craving relief. A prescription is not required for nicotine gum. Use 4 mg if you smoke your first cigarette within 30 minutes of waking. Use 2mg if you smoke your first cigarette more than 30 minutes after waking up.