Which of the following is a common side effect of nicotine replacement therapy?

Nicotine replacement therapy (NRT) is widely used to help people quit smoking by providing a safer source of nicotine without the harmful substances found in tobacco smoke. One of the common side effects of NRT is nausea. This occurs because the body is adjusting to nicotine intake, which can irritate the gastrointestinal system, particularly when doses are higher than what the person is accustomed to.

Nausea can manifest as a side effect due to individual reactions to nicotine, especially in individuals who may not have consumed nicotine regularly or in the same dosage. Additionally, as the person attempts to reduce their dependence on nicotine, they might experience withdrawal symptoms, which can also contribute to feelings of nausea.

Other effects like weight gain or sleep disturbances can occur but are less directly attributed to nicotine replacement itself. For instance, weight gain is often a concern post-cessation due to metabolic changes and cravings for oral gratification. Sleep disturbances might occur due to anxiety related to quitting smoking or withdrawal symptoms, rather than being a direct consequence of NRT. Muscle cramps are not commonly associated with nicotine replacement therapy, making nausea the most relevant common side effect.