Ambien is used to treat insomnia . The immediate-release tablet is used to help you fall asleep when you first go to bed.The typical dosage for adults is 10 mg, taken right before bedtime, and it's recommended to only take it when you have at least 7–8 hours available for sleep. If you're older than 65, then the recommended dose is typically 5 mg to reduce the risk of side effects like dizziness or confusion.