Yeah I use it often. It does increase appetite and in that way increases wieght. The energy is why I am taking it now. I am on a cut and it helps me keep going strong through 3 hours a day training.
The B vitamins form the "core" of many of the enzymes and intermediate steps of the Krebbs cycle and Oxidative phospholoration process' which makes our ATP. In very Laymans terms
I've tried both research grade and pharmaceutical B12 and never felt any difference and never felt all the energy and other good things your supposed to feel