Two female friends of mine recently insisted that I try a sublingual liquid B Complex with B12. You take a dropper of the liquid and hold it under your tongue for 30 seconds before swallowing (up to 4 times a day). I've only used it for a few days but I think I notice a difference :) I know my friends swear by it.
Also, I used to take my grandmother to the doctor for a B12 shot quite often, maybe once every month or two. It definitely made a difference with her energy level. It was noticeable to all of the family. And - gram lived to be almost 103 years old.