what level of b12 requires injections are the benefits injection? B12 Injection Dosage and Frequency:

I tried this on a whim because my doctor had told me I was deficient

Additionally, B12 is involved in energy metabolism, aiding in the conversion of food into energy, and has implications for mood regulation through its role in neurotransmitter synthesis

Be skeptical of specific numbers (e.g., a particular half-life in hours, or a specific oral bioavailability percentage) circulating on commercial or community sites these could not be located in peer-reviewed literature and directly conflict with the peer-reviewed consensus that no human trials of this compound have been conducted

Because oral supplements are absorbed less effectively, you need to take them far more frequently than you would need an injection

Chen, L.K., and Roberts, D.A