How Do I Give B12 Injections?


Vitamin B12, also known as cobalamin, is a water-soluble vitamin essential for proper red blood cell formation and normal functioning of the neurological and nervous systems. The body makes a small amount of vitamin B12 in the gastrointestinal track, but most vitamin B12 is obtained from eating foods such as fish, shellfish, meat and dairy products. Vitamin B12 is stored in the body for many years, but with age these stores are depleted and vitamin B12 is not as efficiently absorbed from foods eaten. People who suffer from pernicious anemia are unable to absorb vitamin B12 from the intestinal tract and require B12 injections to ward off deficiency states.

Step 1

Wash hands and put on latex gloves.

Step 2

Wet a cotton ball with a small amount of alcohol and thoroughly wipe the rubber top of the vitamin B12 vial. Remove the cover of the syringe and draw back on the plunger. By doing so, allow enough air in so that the amount air in the syringe is equivalent to the dose of vitamin B12.

Step 3

Insert the needle into the vial of vitamin B12. Turn vial upside down. Press the plunger to transfer the air in the syringe to the vial. Pull back on the plunger, watching the lines on the barrel of the syringe, until the correct dose of vitamin B12 is in the syringe. Tap the syringe lightly to remove any air bubbles. Withdraw the syringe from the vial. Set vial aside. The needle must remain sterile so do not allow the needle to touch anything.

Step 4

Wet a clean cotton ball with alcohol or use an alcohol wipe to cleanse the skin where the vitamin B12 injection will be applied (see Warnings). Allow alcohol to dry. With your non-dominant hand, grab a large portion of the muscle. With a dart-like motion, plunge the needle (with your dominant hand) into the cleansed area of skin.

Step 5

Pull back slightly on the plunger. If no blood is seen in the barrel of the syringe, push down on the plunger until the entire dose of vitamin B12 has been given. Withdraw the needle quickly from the muscle. Place a cotton ball on the injection site and apply pressure for a couple of minutes. Apply a bandage to injection site. Discard needle in sharps container.

Tips and Warnings

  • This is an intramuscular injection. The needle must go deep within the dorsogluteal muscle, a large muscle located in the buttocks.

    Vitamin B12 can also be given in the deltoids and thigh (vastus lateralis) muscles.

    The thigh is an easier site of injection for a person who is self-injecting.

  • Before giving the injection, it is important to remember the five rights of medication administration: Right patient, right dose, right medication, right time, and right route.

    To give an vitamin B12 shot, it is important to find the the proper site. Divide one buttock into four quadrants. Give the injection in the outer upper quadrant near the hip.

    If blood is present when plunger is pulled back, this a sign that needle has hit an artery or a vein. Withdraw the needle and use a different location.

    Never reuse needles and always discard the needle in a sharps container. Sharps containers are available at most pharmacies or medical supplies stores. If you do not have access to a sharps container use a used bleach bottle or a laundry detergent bottle with a top that screws on tight. Do not use clear bottles or glass containers. Always put containers in the garbage and never in the recycle bin.

    Keep sharps containers out of reach of small children and pets.

About this Author

Shelly Guillory has been a registered nurse for seven years, specializing in the areas of oncology, infectious disease, and psychiatric nursing. Guillory has been writing for six years and is currently pursing degrees in journalism and photography at the University of Utah.