I have been taking b12 dots. You put it under your tongue and let it dissolve. From what I read taking vitamin b pills doesn't work because your body doesn't absorb it as well in the stomach, but under the tongue it goes straight to your blood stream like an injection.
I also take vitamin d3. I can tell when I haven't had my vitamins I will be lagging all day and realize I took the pills out and forgot to take them. (I will set them out while getting ready and wait until after breakfast to take them)
A friend told me she was going in for b12 injections at a weight loss clinic for $20/injection every week. That's $80/month, I got the bottle of dots for under $10...I'll stick with my dots.