You can have the perfect storage conditions, but if you're introducing contaminants with every use, it won't matter
Request the COA and confirm it includes HPLC quantification, MS molecular weight confirmation matched to the stated form, a named third-party lab, and a batch number matching your bottle
Alcohol can interfere with the absorption of vitamin B12 and may counteract the benefits of the shot
If your clinic offers these services, set expectations around the full program (coaching, energy balance, and adherence) rather than the injection alone
If you receive a vitamin B12 shot, the ingredient will most likely contain an injection of cyanocobalamin, also known as hydroxocobalamin or the natural form methyl-cobalamin