b12 aqua injection B-29 AQ Injection: View Uses, Side Effects, Price and Substitute Veterinarians may prescribe vitamin B12 injections to animals with a deficiency Cyanocobalamin Injection, 1000 mcg/mL 1mL
Description
Research from 2015 highlights these risk factors, underscoring the importance of monitoring B12 levels if you fall into these categories

Side effects are rare but may include bruising or soreness at the injection site, a metallic taste in the mouth, or a sensation of coldness during the infusion

Available at: Wikipedia

Heat tends to not be as helpful for this particular task
