Zopiclone is a hypnotic drug that works by modulating the gamma-aminobutyric acid (GABA) receptor. GABAA is one of the major inhibitory neurotransmitters (brain chemicals) in the central nervous system. Simply put, the drug works by depressing the central nervous system so you can fall asleep. However, the exact mechanism is still unknown. It has been presumed that Zopiclone makes you feel sleepy by working on a specific brain chemical.