Administering B12 Injections Safely at Home: A Complete Guide

Learn where to self-administer a B12 shot and how to do it painlessly

Co-authored by Amber Crain | Medically reviewed by Shari Forschen, NP, MA

Last Updated: November 23, 2022 References Approved

Preparing for an Injection

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Administering an Intramuscular Injection

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Tips

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Warnings

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Things You'll Need

If you've been feeling sluggish or low-energy lately, getting B12 injections might help you get back on track (especially if you have a B12 deficiency). Giving yourself B12 injections at home is easier and more convenient than having your doctor do it every time, but doing the first injection can be a little unnerving for most folks! In this article, we'll walk you through the proper injection process so you can easily give yourself (or someone else) a painless B12 shot. We'll also discuss the different injection sites and explain how to dispose of used needles the right way so you're fully prepared.

Things You Should Know

Clean the injection site with alcohol and a cotton ball. Take the lid off the B12 solution and swipe the rubber top with alcohol.
Insert the needle into the B12 vial and pull back the plunger to draw your dose. Pull out the needle and push the plunger slightly to get rid of air bubbles.
Hold the skin tight at the injection site and insert the needle at a 90-degree angle. Push the plunger slowly to administer the full dose.
Clean the injection site with alcohol and put a bandage over it. Put the used needle in a puncture-proof disposal container.

Part 1

Part 1 of 2:

Preparing for an Injection

1
Talk to your doctor about getting vitamin B12 injections. Describe any symptoms you've been experiencing to your doctor, especially things like mental fogginess and overall fatigue, so your doctor can make an assessment. They'll most likely want to do routine bloodwork to check your B12 levels. If your doctor feels you're a good candidate for vitamin B12 injections, they'll give you a prescription for a certain dosage.^{[1]
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- Doctors estimate 1.5% to 15% of people have vitamin B12 deficiency. Adults over the age of 60 are much more likely to experience this issue, but it can happen to people of all ages.^{[2]
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  Cleveland Clinic
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  Go to source}
- Your doctor will show you how to perform the injection. It's best to follow their directions and use this article as a refresher.
- You can fill your prescription at any local pharmacy. Avoid exceeding your recommended dosage on the medication.
- Your doctor may require regular blood tests to monitor your body's reaction to the injections. This is normal.
2
Go over the benefits of B12 injections with your doctor. If you suffer from anemia or a B12 deficiency, you may need B12 as a treatment. If you have difficulty absorbing B12 in food or oral supplements, injections can be a big help. Vegetarians may also benefit from vitamin B12 supplements. Some doctors may even prescribe B12 injections to prevent deficiencies before they start (especially if your bloodwork's numbers are on the low side).^{[3]
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- B12 injections may help with a wide range of symptoms like mental and physical fatigue, irritability, and numbness or tingling in your hands and feet.^{[4]
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  Cleveland Clinic
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- Common conditions like gastritis, anemia, and Crohn's disease can diminish your B12 levels. If you have one of those conditions, getting B12 injections can prevent a deficiency before it starts.
- Vitamin B12 injections alone are not medically proven to help with weight loss. If you're deficient in B12, injections can increase your energy and well-being (which may lead to weight loss).^{[5]
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3
Discuss any possible complications with your doctor. Some people aren't good candidates for this treatment, so be sure to let your doctor know if you have any allergies or health conditions. For example, you shouldn't use this medication if you're allergic to cyanocobalamin or cobalt, or if you have Leber’s disease, which is an inherited form of vision loss.^{[6]
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Trustworthy Source
Mayo Clinic
Educational website from one of the world's leading hospitals
Go to source} Avoid B12 shots if:
- You have kidney or liver disease.
- You're iron or folic acid deficient.
- You're experiencing any kind of infection.
- You're currently receiving medication or treatments that affect bone marrow.
- You're pregnant or plan on becoming pregnant while using B12 injections.
4
Choose an injection site for your medication. There's really no ideal injection site; it depends on your age and comfort level. A healthcare professional should administer your first shot so they can monitor your reaction and check for any adverse effects.^{[7]
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Trustworthy Source
Cleveland Clinic
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Go to source} There are 4 common injection sites for administering B12, but you'll want to discuss what's best for you with your doctor. The injection sites are:
- Thigh: This site works best if you're self-administering your own injections, or if you're giving an injection to an infant or child. It’s a good spot because of the high amount of fat and muscle under the skin of your thigh. The target muscle, vastus lateralis, is halfway between your groin and your knee, about 6–8 in (15–20 cm) from the crease of your leg.
- Outer hip: This site is located on the side of your body just below the hip bone, and it's a good spot for young people and adults. Most doctors advise using this area since there are no major blood vessels or nerves nearby that could be punctured by a needle.
- Upper arm: This site is best for young or middle-aged adults. Older adults can use this site if the muscle in their upper arm, their deltoid, is well developed. If you're dose is higher than 1mL, avoid injecting into the upper arm.
- Buttocks: The upper, outer buttocks, or Dorsogluteals, are located on either side of your body. Only a medical professional should use this site because it's really close to major blood vessels and your sciatic nerve (which could be damaged if the injection is not administered properly).
5
Choose an injection method. Though it may seem like a pretty straightforward process to inject someone with a needle and a plunger, there are 2 injection methods that can be used for a vitamin B12 injection:^{[8]
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- Intramuscular: These injections are common because they tend to have better results. The needle is inserted at a 90-degree angle, deep into the muscular tissue. Once the needle is in the muscle, the plunger is pulled back slightly to ensure the needle is not in a blood vessel. If no blood is aspirated, then the medication can be pushed through slowly. The surrounding muscle will absorb the medication right away.
- Subcutaneous: These injections are less common. The needle is inserted at a 45-degree angle, just below the skin, as opposed to deep into a muscle. The outer skin may be pulled away from the muscle tissue to ensure the needle doesn't pierce the muscle. This type of injection is best administered in the upper arm.

Part 2

Part 2 of 2:

Administering an Intramuscular Injection

1
Wash your hands and clean the injection area with alcohol. Push back or remove any clothes that cover the injection site so the bare skin is exposed and accessible. Moisten a cotton ball with rubbing alcohol and use it to wipe the skin at the injection site.^{[9]
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- Let the alcohol evaporate before proceeding (this only takes a few seconds).
2
Disinfect the mouth of the B12 solution container with alcohol. Moisten another cotton ball with rubbing alcohol and swipe the surface of the container of your medication so the needle will entire a germ-free space.^{[10]
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3
Unwrap a needle and pull back the syringe to line up with your dosage. Measurements will be marked on the side of the syringe. Once the dosage amount is set, go ahead and take off the safety cover on the needle. Don't let the needle touch anything once the cap is off.^{[11]
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- This draws air into the syringe which prevents a vacuum from forming when you push the plunger in the next step.
4
Insert the needle into the rubber top of the B12 solution container. Push the air out of the syringe by pushing the plunger all the way down. Then, slowly pull back on the plunger until the syringe fills to the required amount. Tap the syringe lightly with your finger to remove any air bubbles.^{[12]
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- Avoid touching the needle to the bottom of the glass container since it can dull the point.^{[13]
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5
Hold the skin taut and insert the needle at a right angle. Hold the needle in your dominant hand and use the thumb and forefinger of your free hand to hold the skin taut. Remove the needle from the container and give a slight push on the syringe to dispel a tiny amount of the vitamin B12 supplement before you insert the needle into your skin to ensure the air is out of the syringe.^{[14]
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- If you're injecting someone else, let them know you're about to inject the supplement. If the person appears nervous or tense, advise them to put their weight on the leg or arm that you aren't injecting to help relax the muscles.^{[15]
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- Doctors usually recommend intramuscular injections, which is what we're describing. For subcutaneous injections, pinch the skin and poke the needle in at a 90-degree angle, almost like you're throwing a dart, so it barely goes beneath the surface. The rest of the process is the same, so proceed to the next steps.^{[16]
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6
Push down the plunger slowly to administer the injection. Take a deep breath and relax your muscles. Pull the plunger back a little to check that there's no blood in the syringe. If there's no blood, hold the needle steady and push down the plunger slowly until the full dose is administered into the site.^{[17]
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7
Let go of the skin and remove the needle. Make sure you remove it at the same angle of insertion. Use a cotton ball moistened with alcohol to stop any bleeding at the injection site and to clean the area. Wipe the injection site in a circular motion and put a bandage over the site to protect the wound.
- Never use the same needle twice, as this can lead to infection or illness.
8
Dispose of the needle properly. Do not throw used needles into your regular garbage. You can ask your doctor or pharmacist for a puncture proof disposal container that you can use at home, such as a sharps container, or make your own container.
- To make your own container, duct tape the lid onto a metal coffee can. Cut a slit in the lid that's wide enough for needles to fit through. Label the can so you know it contains needles. Alternatively, store your used needles in a thick plastic detergent bottle. Label the container and keep the lid on at all times.^{[18]
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- When the can is three-quarters full, take it to your doctor’s office, a bio-hazard collection site, a hazardous waste center, or a syringe exchange program for disposal. Alternatively, enroll in a residential "special waste" program that will come pick up your needles.^{[19]
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  United States Environmental Protection Agency
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Warnings

It's important to follow your doctor's specific instructions and avoid injecting anywhere else on your body. If you inject into the wrong area, a painful abscess can form underneath the skin.^{[20]
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Research source} Other than that, though, B12 injections are considered to be quite safe, so try not to worry about doing it "wrong." As long as you wash your hands, work in a sterile environment, and inject into the proper site using the correct technique, you'll do great.

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