Are you struggling to get a good night’s sleep? Ambien has been proven to be one of the most effective treatments for insomnia, but trying to find a reliable place to buy it can be overwhelming. In... Ambien (zolpidem) is a sedative, also called a hypnotic. It affects chemicals in the brain that may be unbalanced in people with sleep problems (insomnia). Ambien is used to treat insomnia. The immediate-release tablet is used to help you fall asleep when you first go to bed. The extended-release form, Ambien CR, has a first layer that dissolves quickly to help you fall asleep, and a second layer that dissolves slowly to help you stay asleep.