Ivy Grove Surgery : Self administration of B12 injection Why Do I Feel Worse After My B12 Injection: 6 Body Reactions Some people think the needle is left in their arm when they have IV. In reality, it's only a small plastic catheter that is easily bendable. So don't be afraid to move 3 Easy Ways to Reduce Pain After an Injection wikiHow Understanding B12 Deficiency: Signs on Hands and Feet Feeling worse after B12 Injection: Answering concerns. La Vie Med Spa