if you are b12 deficient it will help a lot! otherwise...maybe a little. i just bought the liquid b complex instead of getting injections. i think it helps a bit. my mom who is late 60's and not an addict gets the injections because she is deficient. you may or may not be lacking in Bs.
as an aside, i've tried stimulants with caffeine in them for energy and it makes you feel the WDs much much more. personally, i'd rather be tired.
Kova
I've taken them; can't say I felt "great" afterwards, but it may have helped a little. Don't expect an immediate burst of energy. If you keep taking it though, you should see some results. Take some Vitamin C also; that helps.