How To Self-Administer Vitamin B12 Injections

Many people use vitamin B12 injections to replenish their vitamin B12 levels, providing extra energy, vitality, and many other benefits. Vitamin B12 injections have different effects depending on your vitamin B12 status. Going to an injection clinic or doctor’s office for each injection is a hassle, and the fees add up. Learn how to self-administer vitamin B12. If the following instructions differ from what you were told by your healthcare provider, follow their instructions. Based on your health needs, your doctor has decided how much B12 to give you and where to give it.

Intramuscular B-12 Injection Steps

Vitamin B12 injections steps may look a little intimidating at first glance, but once you get the hang of it, they will become second nature.

Step 1: Gather Your Supplies

In a clean, well-lit room, collect all necessary items, including:

The medication vial
The syringe and needle
Two alcohol prep pads
Adhesive bandages or cotton balls
The package insert with the dosage information

Step 2: Draw Up the Medication

Wash your hands with soap and water.
If your medication is stored in the refrigerator, let the medication come to room temperature to reduce injection discomfort.
Peel the cap off the top of your medication vial (if opening a new vial). Next, open your alcohol prep pad and clean the rubber membrane of the medication vial thoroughly using a circular motion. Let dry. This will kill bacteria on the vial and reduce the risk of contaminating your medication.
Open a fresh syringe and needle. Screw the needle onto the syringe without removing the needle cap (if not preassembled). Pull the plunger on the syringe up and down several times to loosen it before uncapping the needle. Look at the syringe barrel and note the unit numbers along the syringe shaft. Identify the line that indicates your prescribed dose.
Uncap the needle while being very careful not to allow the needle to touch your hand, table, or other surfaces.
Hold the syringe upright with the needle facing up. Pull back the plunger to fill the syringe with air just past the prescribed dose.
Hold the syringe with the needle facing straight down and insert the needle through the center of the rubber membrane.
Flip the syringe and medication and inject the air into the vial.
Make sure the tip of the needle is in the medication liquid and that the syringe is rotated so you can see the dosage lines on the syringe. Withdraw the correct amount of medication into the syringe just past your prescribed dose. Push the plunger so that the top of the plunger is level with your dose, expelling any air bubbles by tapping on the syringe.
Then, pull the needle from the vial and replace the cap on the syringe, taking care not to bend the needle or touch any surfaces outside of the needle cap.

Step 3: Choose Your Injection Site

Intramuscular injections can be given into your upper buttocks, outer thigh, or shoulder muscle.

Ask your healthcare provider which injection sites are appropriate for you. Needle size and length may vary depending on the injection site.

The upper buttock is most commonly used for intramuscular injections. In order to avoid irritating the nerves, it’s important to inject in the upper outside quadrant of the buttock. This site is commonly used if someone is injecting the shot for you.

If you are injecting yourself, the outer thigh is commonly used.

Alternate injection sites and avoid any injection sites that are bruised, scarred, or covered with a skin rash.

A close-up of an injection into a person's upper arm.

Step 4: Injecting Your Medication

Use an alcohol prep pad and a circular motion to clean your injection site well. Allow your skin to dry. Have a cotton ball or adhesive bandage ready. To lessen the pain, use your non-dominant hand to pull the skin tight around the injection site. Hold the syringe and needle, so they are at a 90-degree angle to the injection site. Push the needle into the muscle using a firm, smooth motion.

Slowly push the plunger in to fully inject the medication. Pull the needle and syringe out and place them in a sharps container. Apply pressure to your injection site using a cotton ball or adhesive bandage. Store your medication as directed.

Using a metal coffee can and duct tape, you can make your own sharps container. Make a slit in the plastic lid to insert the used needles. Duct tape the lid to the container. Label the container as used needles. Dispose of the container following local biohazard waste instructions.

Frequently Asked Questions About Vitamin B12 injection

As you become more comfortable injecting vitamin B12, you will probably develop your own techniques and preferred injection sites.

Does the needle go all the way in for a B12 injection?

Yes, your needle length is chosen based on your injection site, body fat, and the consistency of the medication you are injecting. Push the needle into the muscle until the hub of the needle touches the skin.

Where is the best place to give yourself a B12 injection?

Follow your doctor’s instructions when choosing your vitamin B12 injection site. Many people choose the upper lateral quadrant of the buttock when someone else is giving them a B12 injection and the outside of the thigh when they are giving themselves a B12 injection. If injecting into the outer thigh, the injection site is halfway between your groin and knee.

How much vitamin B12 do I need?

The recommended daily allowance for vitamin B12 is 2.4 mcg for nonpregnant, non-lactating adults.

What symptoms may indicate a vitamin B12 deficiency?

Common symptoms of vitamin B12 deficiency include:

Fatigue
Irritability
Difficulty sleeping
Numbness and tingling in hands and feet
Ringing in the ears
Confusion, memory problems
Muscle weakness
Shiny, painful tongue

What are the risk factors for vitamin B12 deficiency?

People at the highest risk for vitamin B12 deficiency include:

People taking high doses of folic acid.
Older adults because they produce less stomach acid.
Anyone who has had stomach surgery.
Anyone taking metformin or proton-pump inhibitors for more than four months.
People who consume a vegan or vegetarian diet.
Anyone who consumes alcohol excessively.

How often should I take a B12 injection?

The effects of a B12 injection should be noticed within 48 to 72 hours if you have a vitamin B12 deficiency. A common vitamin B12 injection protocol is to inject weekly for four weeks. But your doctor may suggest different vitamin B12 injection schedules and dosages based on your symptoms and treatment goals. At the end of your treatment cycle, your healthcare provider will review your symptoms and response to vitamin B12 injections to determine whether you need a longer course of treatment or a higher dose.

Looking to get vitamin B12 injections? See how Invigor Medical can help today!

Disclaimer

While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.

References:

Green R, Allen LH, Bjørke-Monsen AL, Brito A, Guéant JL, Miller JW, Molloy AM, Nexo E, Stabler S, Toh BH, Ueland PM, Yajnik C. Vitamin B₁₂ deficiency. Nat Rev Dis Primers. 2017 Jun 29;3:17040. doi: 10.1038/nrdp.2017.40. Erratum in: Nat Rev Dis Primers. 2017 Jul 20;3:17054. PMID: 28660890.

Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B(6), Folate, Vitamin B(12), Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academies Press; 1998.

Langan RC, Goodbred AJ. Vitamin B12 Deficiency: Recognition and Management. Am Fam Physician. 2017 Sep 15;96(6):384-389. PMID: 28925645.

NIH. (n.d.). Vitamin B12. Retrieved from https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/#en5