is vitamin b12 injections subcutaneous or intramuscular B-12 vs. Injection What happens if you inject

del Rincon J-P, Iida K, Gaylinn BD, McCurdy CE, Leitner JW, Barbour LA, Kopchick JJ, Friedman JE, Draznin B, Thorner MO

But this does not mean that all the B12 contained in the tablet will be absorbed, as it also depends on how much intrinsic factor is available for its absorption

This medicine is administered into a vein by a healthcare professional and will only be given to you if your doctor thinks that an injection is more suitable for you at the moment than a tablet

The time it takes for B12 to work will depend on the form, how you take it, the dosage, and your current B12 status

Signs You May Need B12 Shots: Ware's Expert Assessment Rebekah Jun 16, 2025 7 min read Updated: Nov 3, 2025 What Are the Early Warning Signs of B12 Deficiency