Lunesta is a brand name for the medication known as eszopiclone. It is a non-benzodiazepine sedative-hypnotic primarily used for the treatment of insomnia. Lunesta works by enhancing the activity of the neurotransmitter gamma-aminobutyric acid (GABA) in the brain. GABA helps to calm down brain activity and induce sleep. This is approved for the treatment of insomnia characterized by difficulty falling asleep or staying asleep. It is intended for short-term use, typically no longer than 7 to 10 days.