Where Do You Inject Vitamin B12?

Cyanocobalamin, or manmade vitamin B12, is best injected in a muscle or under the skin. The amount of injections a person requires will be determined by a doctor.

Vitamin B12 injections are used to treat or prevent a lack of B12 that may be caused by infection, medications or diseases. People who follow a strict vegan or vegetarian lifestyle may also suffer from a lack of B12.

The National Institutes of Health warn that B12 may cause side effects such as muscle weakness or pain, diarrhea, coughing, dizziness, headache or red skin. Patients receiving regular B12 injections should contact their doctor if side effects become troublesome or severe.

When choosing the needle for the injection, it should be long enough to go through the specific muscle. The needle gauge typically used is between 22 and 25 gauge. Similarly, the needle length is dependent on other factors such as the muscle used for the injection and age and size of the patient, explains Scott & White Healthcare.