Like most things, the answer isnt cut-and-dry, but lets break it down together to understand what factors influence this timeline and what else these powerful shots can do for you
Tkalevi VI, ui S, Braja K, Mildner B, Bokuli A, itum K, et al
These operate through a completely different mechanism - mimicking a hormone that regulates appetite and blood sugar - with a substantially larger clinical trial evidence base and a different side effect and cost profile
Typically, B12 injections contain a higher concentration of the vitamin compared to oral supplements to ensure adequate absorption
Vitamin B 12 can also be absorbed by passive diffusion, but this process is very inefficient only about 1% to 2% of the oral vitamin B 12 dose is absorbed passively (2)