Varenicline is a partial nicotinic agonist which acts on alpha4 beta2 nicotinic receptors. It is presumed to alleviate withdrawal discomfort, but also to diminish rewarding effects of cigarettes. The standard varenicline dosing has been formulated to avoid adverse reactions (primarily nausea) in sensitive clients. The downside of this cautious approach is that a substantial proportion of clients may be under-dosed. A blanket dose increase would inevitably increase the incidence of side effects, but it is likely that tailoring varenicline dosing to clients' needs would be safe and may further increase varenicline's efficacy.