Varenicline (CP 526555), a cytisine-based nicotinic ligand, is a potent partial agonist for the α4β2 nicotinic acetylcholine receptor (nAChR) with an EC50 value of 2.3 μM and acts as a full agonist for α7 and α3β4 nAChRs, with respective EC50 values of 18 μM and 55 μM [1]. Notably, its effectiveness and potential in smoking cessation treatments are underscored by its pharmacological profile [2].