Both the B12 injections and Lipotropic injections contain vitamin B12; however, the lipotropic injections offer additional nutrients which further the weight loss journey. Common lipotropic nutrients found in the injection include choline, methionine, inositol, and betaine.   Each compound is responsible for maintaining a healthy liver; however, when it comes to weight loss, the lipotropic nutrients used in the injection will help the fat to metabolize more efficiently than with just vitamin B12 injections alone.