Ambien is a prescription sedative-hypnotic medicine. Doctors and Medical experts use this medication to help people to sleep who are suffering from sleeping problems. Buy Ambien online from a medical store and use it to treat your insomnia. How should you take Ambien? The Immediate-release tablet of Ambien helps you fall asleep quickly. Ambien CR, an extended-release tablet, has two layers. The first layer of medicine will dissolve quickly to help you fall asleep faster, and the second layer will dissolve slowly to help you stay asleep for 7 to 8 hours.