how long after vitamin b12 injections take to work Fast Does a Shot Work? How Quickly Does B12 Shot

doi:10.1210/jcem-67-6-1186

(The standard route for this molecule is oral

When deficiency is suspected based on clinical features (fatigue, paraesthesia, cognitive changes) or risk factors (vegan diet, gastric surgery, certain medications), serum B12 measurement guides appropriate intervention

For example, if you have a deficiency and need regular B12 injections, hydroxocobalamin can be given once every 3 months, whereas cyanocobalamin would need to be given every month

** Product contains benzyl alcohol as an inactive ingredient Contraindications for Benzyl Alcohol This preparation is not advised in patients who are sensitive to cobalt and/or vitamin B12

you might have some soreness, redness, or a small lump where the shot was given