Nicotine gum is another common FDA-approved NRT product that is easily obtained at a local pharmacy. 

Some nicotine gum chewers experience: 

• bad tastes in their mouth from the chemicals;
• a tingling feeling on the tongue while chewing the gum;
• upset stomach;
• nausea;
• heartburn; and
• hiccups. 

Other less common forms of NRT products include lozenges, which when dissolved in the mouth, can cause upset stomach, heartburn, hiccups, headaches and excessive gas, especially if swallowed whole. Two NRTs available only by prescription are inhalers and nasal spray, both of which count throat irritation and coughing among the side effects.