A 2018 Cochrane review found that it produced moderate improvement in sleep onset and maintenance. The authors suggest that where preferred non-pharmacological treatment strategies have been exhausted, eszopiclone provides an efficient treatment for insomnia. In 2014, the US Food and Drug Administration asked that the starting dose be lowered from 2 milligrams to 1 milligram after it was observed in a study that even eight hours after taking the drug at night, some people were not able to cope with their next-day activities like driving and other activities that require full alertness.
Eszopiclone is slightly effective in the treatment of insomnia where difficulty in falling asleep is the primary complaint. The benefit over placebo was found to be of questionable clinical significance. Although the drug effect and the placebo response were rather small and of questionable clinical importance, the two together produce a reasonably large clinical response.