injection instructions for methyl-b12 shots B12 at Home: How, Where & How Often to Inject Yourself Best Vitamin B12 Injection Site:

The reason is that if it is injected into veins a portion of the shot may pass out of the body through urine

Call your health care provider immediately if you are experiencing any signs of an allergic reaction: skin rash, itching or hives, swelling of the face, lips, or tongue, blue tint to skin, chest tightness, pain, difficulty breathing, wheezing, dizziness, red, swollen painful area on the leg

Vitamin B12 ranks among the most common vitamin deficiencies, and it can significantly compromise your immune system

These are generally shortlived

Regular monitoring may be appropriate, especially if symptoms of deficiency develop