Ambien is used for the short-term treatment of insomnia (difficulty falling or staying asleep). This medication causes relaxation to help you fall asleep. You may buy Ambien online affects chemicals in your brain that may become unbalanced and cause sleep problems (insomnia). Ambien is used for the short-term treatment of insomnia (difficulty falling or staying asleep). This medication causes relaxation to help you fall asleep. Ambien may also be used for purposes other than those listed. Consult a doctor for more information.