As someone who has chased the sleep dragon for years, I would caution anyone against the long term usage of a sleep aid. At a bare minimum you'll have to mix it up to avoid a dependency, even OTC meds.
Melatonin, Benadryl (also the active ingredient in most "PM" pain meds or Zzzquil), sublingual gel caps, a small snack, and even a shot of booze with one of the above...large doses, small doses, mixing the meds will all work, but at some point I've had to suck it up and go without, allowing myself to "detox" as it were. I have yet to meet anyone who didn't develop a dependency on OTC meds and prescription sleep medication is the devil.