They are super friendly, enthusiastic, and knowledgeable
The bruising side effects appear locally in the injection areas and are primarily a temporary cosmetic problem
Animals, in turn, must obtain it directly or indirectly from bacteria, and these bacteria may inhabit a section of the gut which is posterior to the section where B12 is absorbed

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
If your cat is at the point where it will NOT eat, try to find one thing they can stomach
Fatigue affects more than your sleep schedule it impacts your productivity, mood, and quality of life