I'll second Melatonin. I carry a bottle in my toiletries and take one if I have a really tough schedule change (i.e. first 3 days are late shows, followed by a reduced rest 0530 show). For me it's very gentle and puts me to sleep naturally without knocking me out. When I wake up in the morning I don't feel drugged or groggy at all. Works like a champ, and it's 100% safe and legal.