Donepezil is a reversible acetylcholinesterase inhibitor that readily crosses the blood-brain barrier to reduce the breakdown of acetylcholine. It has a half-life in circulation of about 70 hours. As acetylcholine modulates plasticity, excitability, and arousal in the central nervous system, donepezil is commonly used in the treatment of Alzheimer’s disease to improve cognition, memory, and behavior. In this way, it is intended to prevent or reverse dementia. Studies on these effects have been equivocal, indicating that more research into the therapeutic potential of donepezil is warranted.