Restoril belongs to a group of drugs called benzodiazepines ( ben-zoe-dye-AZE-eh-peens) . It affects chemicals in the brain that may become unbalanced and cause sleep problems ( insomnia) . Restoril is used to treat insomnia symptoms, such as trouble falling or staying asleep. Each 15mg Capsule cost US$ 0.79 for 4 days delivery and $ 0.46 for 8 days ordinary delivery