Buy Lunesta 1mg, 2mg & 3mg Online Lunesta (eszopiclone) is a sedative, also called a hypnotic. It affects chemicals in your brain that may be unbalanced in people with sleep problems (insomnia). Lunesta is used to treat insomnia. This medicine causes relaxation to help you fall asleep and stay asleep. Lunesta may also be used for purposes not listed in this medication guide.