Ambien is indicated for the temporary treatment of insomnia in people in situations where the insomnia is debilitating or causing severe distress to the patient. Ambien is a sedative, also known as a hypnotic. Ambien is fast-acting and eliminated from your system reasonably quickly. Ambien affects chemicals in your brain that might be unbalanced in people with sleep problems or insomnia. Thus, you can buy Ambien online overnight to enjoy a restful sleep because the Ambien drug helps treat insomnia.