Fill the syringe with the solution, then form a pocket of skin by pulling up on your dogs loose skin, usually behind its shoulders
GoodRx describes these prescription-only medications as having "good clinical data showing that they're safe and effective when used as directed" under a provider's supervision (goodrx.com)
Reported side effects are generally mild and include temporary gastrointestinal discomfort, headaches during initial use, occasional fatigue as the body adjusts, and rare nausea, especially when taken without food
For maintenance or prophylactic use (such as in a patient with short-gut syndrome who cannot absorb oral vitamins well), a common regimen is 1 mL IM once weekly
B12 needs to be converted into its active form, methylcobalamin to be usable in the cells of your body
B12 shots are made from hydroxocobalamin or cyanocobalamin, manufactured forms of vitamin B12