Taking sleep medication at age 17 would not be a wise act. There are many kinds of insomnia and each has its own cause. Insomnia might include difficulty falling asleep or difficulty staying asleep or difficulty going back to sleep or difficulty with early awakenings and all of those are somewhat different. It would be far preferable to see your physician or obtain a referral to a sleep specialist for more detailed evaluation. Anxiety and depression as well as lifestyle and schedule demands often manifest as depression and it would be worth exploring this in detail.

Safe only if the reason for the sleep problem is analyzed. Non-medical approach like CBT has been shown to be superior to pills.