I don't take any single supplement to feel better but I try to do a few things.
When I eat smaller meals and drink water throughout the day I seem more alert. At breakfast I have: protein shake, multivitamin, korean red ginseng, and salmon+anchovie+sardine oil supplements (omega3)
Sleep in a cooler room and only for around 7 hours. If I sleep more than 7 I feel groggy when I wake up. There is a downside; I get wiped out around 4:00PM so then take a nap for say 20 mins in a totally dark room, and when you get up have some fruits with lots of natural sugars. I'll eat banana and blueberries with water. That will get me feeling better for the rest of the day.
Thats just how I go at least.