Commonly used as an insult, someone with a fadgehead has a women's vagina on their forehead, usually slightly off-centre. Where it has been derived from is unclear.
Either liquid niquil or any liquid drink with melatonin, Ashwaganda or other sleeping aids in a liquid form. If warm tea helps you get to sleep that could be sleepy juice too.
I could not sleep so I chugged some sleepy juice and now I'm so tired and sleepy.