[A short pause, while she thinks on it again. Hmm - ]

Have you considered masturbating before bed? Following male orgasm, the hormone prolactin is released -- one's prolactin levels are higher during sleep, and animals injected with prolactin often become tired immediately. The body also releases oxytocin, which reduces stress levels...

Ah, and if you are seeing someone, you could have sex with them as well! Orgasms during intercourse release four times the prolactin of those had during masturbation.