I don't think B12 helps with weight loss but it does help with low energy and that's a big thing in itself. I would get blood work done first to see if you are deficient. I say this because I used to take the shots to help with energy and they helped a lot but the last time I did, turns out it wasn't lack of B12 that was causing low energy and I ended up with 4 x the amt of B12 required for optimal health. My advice is to talk to your doc or nutritionist first.