Common side effects of the lozenge include hiccups, headache, indigestion, gas, nausea, diarrhoea, sore throat, and mouth irritation. Most users rate these reactions as mild. If side effects do not fade within a week or two, or they worry you, see your pharmacist or doctor.
Serious side effects are uncommon, and are described in the Consumer Medicine Information (pack insert) that comes with the lozenge. If you have these symptoms, follow the instructions in the leaflet and see a doctor as soon as possible. Do not smoke.
Using the lozenge is always safer than continuing to smoke. Tobacco smoke contains many cancer-causing substances, carbon monoxide and other dangerous chemicals, which the nicotine lozenge does not. Unlike smoking, nicotine is not a major cause of increased risk for cancer or heart disease. The lozenge does not increase the risk of heart attack in smokers who have stable heart disease.
It is important to store the lozenges so that children and animals cannot get them, as they can be dangerous for them.