For sleep I would suggest he start drinking chamomile tea on an empty stomach. It contains a fair amount of tryptophan which converts to serotonin to relax the body. Though protein blocks this conversion, and amino acids like tryptophan can be blocked from absorption by other amino acids. This is why it should be taken on an empty stomach. Hops are a good sedative too, but they need to be aged.
Fresh hops are more estrogenic, and they become more sedative with age.
I also like scullcap and passion flower for sedatives.