Discuss how long does Ambien stay in your system, & some factors that influence Ambien's onset. know Ambien withdrawal timeline & its detox. Ambien is a prescription medication used to treat insomnia. It is fast-acting and eliminated from the system fairly quickly. It can be detected in urine for 24-48 hours and in blood tests for 6-20 hours. Hair tests can detect it for up to 5 weeks.