Smoking while using the nicotine inhalator, lozenge, mouth spray or gum does not increase health risks compared to smoking alone. If you reduce your smoking while using any of these products, your nicotine blood levels are likely to be no higher than when you were smoking only.
In studies, there have been no reports of serious side effects from using these nicotine replacement products while smoking. However, some people may have mild symptoms such as sore mouth or throat, and a few people may experience nausea or vomiting.
Serious side effects from using nicotine replacement products are uncommon. They are described in the Consumer Medicine Information (pack insert) that comes with nicotine replacement products. If you have these symptoms, follow the instructions in the leaflet and see a doctor as soon as possible. Do not smoke.