“What sleep medications can I take during the flight?”

If you are a pilot or flight crew, all sleep aids are "No FLY" until 3 half-lives have passed. Even OTC Benadryl has a no fly of 60 hours. Most are 24 hours, but a few are longer. Best consult with your pharmacist or physician about the half life.

However, if you are a passenger, it should not be an issue. Shorter acting sleep aids would be better as you may be groggy after landing given the higher cabin altitude you will be experiencing.