ghb or gbl, i used it for 6 months straight when i was on anadrol and other juice that f'ed up my sleep. a couple caps when i was ready for bed and within 20 mins i was deep asleep. g suppresses dopamine in the brain and when it wears off, it releases it all at once so you wake up wired. i had to wake up early so it worked out well for me, but if you need to sleep more than 4 or5 hrs, you may have to take another dose in the middle of the night. i felt great on 5 hrs sleep, i wasn't tired all day and was wide awake in the gym.
if you are looking for something otc, simply sleep is ok.