Melatonin

Melatonin is a very well researched and understood compound. It's relatively safe to take even daily. There are two types of melatonin - immediate release and extended release. If you have trouble falling asleep in general, melatonin is actually a really effective strategy in the short term. The other thing that melatonin can be useful for is if you are transitioning between Time zones. I'm in Houston today if I'm flying to Tokyo tomorrow I would use melatonin on my circadian cycle.