how long does a b12 injection last Vitamin Injections in Greater Boston Feeling worse after B12 Injection:

HI, you would need to check what strength the ampoule / box says

Once a person receives a dose of vitamin B12 injection, it is distributed throughout the body to start performing its duties

Injections bypass the digestive system, delivering B12 directly to the bloodstream

At the cellular level, B12 acts as a cofactor for two critical enzymatic reactions: Methionine synthase converts homocysteine to methionine, essential for DNA methylation and synthesis Methylmalonyl-CoA mutase involved in fatty acid metabolism and myelin production By restoring adequate B12 levels, injections enable normal red blood cell maturation in the bone marrow, correcting the megaloblastic anaemia