We limit the rate at which you can have a B12 injection to every 28 days
Method Absorption Rate Advantages Disadvantages Oral pills 1.2-40% depending on intrinsic factor Convenient, widely available Poor absorption, especially with age or GI issues Sublingual Slightly better than pills No need for intrinsic factor, easy to use Still less effective than injectable forms In-clinic IM injection Nearly 100% Highly effective, professionally administered Requires clinic visits, potential travel and waiting time At home B12 injection Nearly 100% Highly effective, convenient, no travel needed Requires training, prescription, and comfort with self-injection IV infusion 100% Immediate delivery to bloodstream Most expensive, requires professional administration For many people especially those with serious deficiencies, digestive disorders, or pernicious anemia at home B12 injection offers the sweet spot of effectiveness and convenience

Remember that everyones body is different, but with consistent medication use and lifestyle adjustments, you can expect steady, gradual weight loss over the course of your treatment
I think its because patients are malnourishedthey don't have an appetite, they lack protein and nutritionand their bodies [dont have what they need] to build scar tissue and heal properly. When Dr