Lunesta (eszopiclone) is a non-benzodiazepine sedative-hypnotic used to treat insomnia, including trouble falling or staying asleep. It works within 30 minutes to help you fall asleep faster and sleep longer. Lunesta enhances the effects of GABA, a calming neurotransmitter in the brain, to slow brain activity and promote sleep. Though not a benzodiazepine, it has similar effects with more selective action on sleep-related GABA receptors.