how fast does b12 injection work Quickly Do Shots Work? Benefits and Timeline How Long Does a B12

Withdraw the needle and apply pressure to the injection site using gauze, a cotton ball, or a bandage

For people who dont absorb B12 well, or those whose want to make sure beyond reasonable doubt that theyre getting an ample dose quickly, B12 shots are available via prescription, says Richard Foxx, M.D., a board-certified physician who treats hormonal disorders and nutritional deficiencies

Its helpful to track how you feel in the days following your first shot

Common experiences after the first injection include: Mild soreness or redness at the injection site (usually resolves within 12 days) Slight improvement in energy levels or mood No immediate noticeable change (particularly common if deficiency is severe) Rarely, mild side effects such as headache or dizziness Some patients report their urine becoming brighter or more intensely coloured following injection, which occurs because excess B12 is excreted renally