This synthetic vitamin B12 is the same type found in fortified cereals, so you may have ingested man-made vitamin B12 in your life already
Sohail M, Pirzada T, Guenther R, Barbieri E, Sit T, Menegatti S, Crook N, Opperman CH, Khan SA
Some plastics in syringes can cause the peptide to adsorb or degrade over time, potentially altering the effective dose administered
Mitochondria and lipid peroxidation in the mechanism of neurodegeneration: finding ways for prevention
You would need a 3ml syringe for the higher doses, which reduces measurement precision because the graduation marks are spaced further apart
The burden of healthcare-associated infection in Australian hospitals: a systematic review of the Literature