Administering Vitamin B12 Shots: B12 Injection Sites

Medically reviewed by Leann Poston, M.D. on 9/29/20

What Is a B12 Injection?

Do you think your body gets enough vitamin B12? Vitamin B12 is an incredibly important vitamin used to keep the body, brain, nerve, and blood cells healthy; it also helps make your DNA. Luckily, vitamin B12 can be easily supplemented with B12 shots, and there are multiple locations on your body that can be used as a B12 injection site. If you are experiencing a vitamin B12 deficiency, with symptoms such as tiredness, weight loss, and constipation, B12 injections are an effective and rapid treatment for your body to quickly and efficiently absorb the vitamin it needs (NIH, n.d.). Symptoms can be subtle, but B12 shots can completely change how you feel on a day to day basis.

There are four different kinds of vitamin B12 supplements. A vitamin B12 injection normally contains cyanocobalamin, which is man-made. This is the inactive form of vitamin B12 that requires the body to expend more energy to convert and remove a cyanide molecule than other forms of B12. Another man-made injectable form of vitamin B12 is hydroxocobalamin, which lasts longer in the blood stream and requires fewer injections than cyanocobalamin. The mitochondrial form of the B12 vitamin is adenosylcobalamin, which is naturally occurring but is the least stable of the four options. Vitamin B12 injections also comes in the form of methylcobalamin, which is found naturally in foods, and is the most active form of B12. As opposed to cyanocobalamin, it is ready to be used by the body and is usually the most ideal and effective method for vitamin B12 injections.

B12 is an essential vitamin, which we typically get through our diet. Food sources of vitamin B12 include beef, dairy, poultry, and fish. There are many reasons why you may be low on vitamin B12, but treatment for these symptoms is fairly easy. B12 supplements come in multiple forms, one being an over the counter orally ingested pill. For people who have a hard time absorbing vitamin B12 from the intestine; however, B12 injections are an effective alternative method to treat symptoms and give your body the vitamin B12 it needs to function. Once you learn the options for B12 injection sites and you realize the benefits and straightforward steps of a vitamin B12 injection, it may be the best solution for you and an easy way to treat the symptoms of conditions such as a vitamin B12 deficiency and anemia.

Where Can I Inject a B12 Shot?

Vitamin B12 deficiency is most commonly treated with either intramuscular or subcutaneous injections. Intramuscular injections typically have better results and inject the medicine directly into the muscle, which is then absorbed by the surrounding muscle immediately. While less common, subcutaneous injections are still an effective injection method where the needle is inserted just below the skin. For subcutaneous injections, the best site is your upper arm.

There are three common B12 injection sites. A healthcare professional can determine which site and method is best for you, as the right dosage, frequency, and injection site depends on your age, health, and comfort level. The thigh is the most common injection site for intramuscular self-injections, but one may also inject the vitamin B12 shot at the shoulder and the upper buttocks. Experienced doctors commonly give a B12 shot in the deltoid muscle, but this is more difficult to do if you are just learning. If you are alone, the outer- anterior thigh is likely the easiest way to administer the injection.

What Supplies Do You Need for a B12 Injection?

B12 Injections, once learned and practiced, are easy to administer and require few supplies.

Also read – Why B12 Shots at Home Can Make Your Treatment Easier!

Before finding the right B12 injection site for you, gather the following supplies:

  • Methylcobalamin, Vitamin B12 Solution
  • Clean Needle and Syringe
  • Alcohol pads, or cotton balls and rubbing alcohol
  • Gauze
  • Bandages
  • Puncture-proof container for needle disposal

How Do I Inject a B12 Shot?

It is recommended that anyone who administers a B12 injection should receive training and guidance from a professional health expert. While needle size, dosage, and injection site will vary from person to person, these are the general tips and steps to follow when injecting a B12 Shot.

The way you inject a B12 shot depends on which B12 injection site you choose to use. It is essential always to clean the injection area with alcohol pads or rubbing alcohol and a cotton ball. Allow the injection site to dry completely before administering the shot. Always clean the top of the vial that contains the B12 solution with a new cotton ball and let dry. It is important to rotate your B12 injection sites to keep your skin healthy, as repeated shots in the same site may cause scarring or swelling. No matter where you inject the vitamin B12 medicine, it is important to hold the skin taut to tighten the skin and prepare the muscle. The skin should be smooth, and the muscles should be relaxed.

Intramuscular B12 Injection

For an intramuscular B12 injection, you should fasten the needle onto the end of the syringe. Fill the syringe with air using the plunger until you reach your suggested dosage. Then, turn the B12 solution container upside down so that when you insert the needle into the surface of the container, it is facing upwards towards the sky. After inserting the needle into the container, release the air from the syringe into the vial and then slowly pull on the plunger to withdraw the correct amount of vitamin B12 into the syringe.

When inserting the needle for injection intramuscularly, hold it at a right angle (90 degrees) and withdraw the needle at the same angle. You should insert and withdraw the needle quickly but in a controlled way. You will know you are in the right B12 injection site if there is no blood going into the syringe when you pull on the plunger of the syringe slightly. If there is blood going into the syringe when you pull back on the plunger, that means the needle is in a blood vessel, and you must withdraw and prepare the B12 medicine with a new needle.

After a successful injection, apply pressure with a cotton ball or bandage to stop any bleeding. Always place your used needles in an approved biohazard container and dispose properly of your injection waste. After injection, you can rub the B12 injection site in a circular motion, which will increase blood flow and ease any irritation. These tips will help ensure a painless and safe injection.

Intramuscular B12 Injection Sites

The Thigh

If you are self-administering the shot, it is recommended that you use your thigh.

To give an injection in your thigh, sit down and divide the top of your thigh into three equal parts. Make a triangle with your thumb and forefinger and hold the flesh in the outer middle section of the thigh firmly. Give the injection in the center of the triangle. This thigh muscle is called the vastus lateralis.

The Buttocks

If you are giving a shot in the upper buttocks region, the injection is best done in the outer and upper region of the muscle and is most effective if someone trusted helps you to administer. The person giving the injection will make a triangle with their thumb and forefinger and hold the flesh inside the triangle tightly. Insert the needle in the center of the triangle to administer the B12 injection. Unless instructed by a health care provider, this injected site is not recommended because untrained injectors may damage the sciatic nerve.

The Arm

If you are giving a B12 injection in the arm, make a downward-facing triangle with your thumb and forefinger over the deltoid muscle, which is on the upper arm near the shoulder. To find the deltoid, feel for the bone at the top of the upper arm and give the injection two finger widths below this bone. Insert the B12 injection needle into the center of the triangle you created with your fingers.

Subcutaneous B12 Injection

Subcutaneous B12 injections are an alternative to intramuscular shots and may be a less painful method for some patients, although they are less common. A subcutaneous injection uses a shorter needle to inject the B12 solution into the tissue layer between the skin and muscle, but it may be a slower absorption rate than other methods of administration. The best method depends on you, your need, and your comfort level with B12 shots and the subcutaneous method may be the most useful, safe, and convenient way for you.


Subcutaneous injections are administered into fat under the skin, so instead of the needle going in at a 90-degree angle, the subcutaneous injection angle is at 45 degrees so that it pierces the skin but not the muscle tissue. The angle of the shot does depend on how much fat you have under your skin, so please consult with a trusted healthcare professional to determine what angle is best for you.

The same initial steps of washing your hands and cleaning the injection site also apply to subcutaneous shots. For a subcutaneous injection, the B12 needs to be injected into the fatty tissue just below the skin. After cleaning your hands and the injection site, prepare the syringe with medication. Use a new needle and syringe for every injection and be careful to not touch the needle in the process. After attaching the needle and syringe, draw the plunger back to fill the syringe with air up to the required dosage. Remove the cap from the vial of B12 solution, and clean with a new alcohol swab, one that is separate from what was used to clean the injection site, then let dry. Remove the cap from the needle and push the needle into the vial. Inject the air into the vial, which will regulate the pressure inside, and then turn the vial and syringe upside down so the needle is upwards. Pull back the plunger to withdraw the correct amount of B12 medication and tap the syringe to remove any bubbles. When you are giving a B12 injection subcutaneously, you pinch the fat to make sure you’re only penetrating the subcutaneous tissue (or the innermost layer of skin) and pull it away from the muscle, then thrust the needle in.

After a successful injection, apply pressure to stop any bleeding. Always place your used needles in an approved biohazard container and dispose properly of your injection waste. After injection, you can rub the B12 injection site in a circular motion, which will increase blood flow and ease any irritation.

Subcutaneous B12 Injection Sites

The Lower Abdomen

This is one of the most common subcutaneous vitamin B12 injection sites and is to be administered at or under the level of the belly button. It should be injected about two inches away from the navel itself. Take your thumb and index finger to pinch about 1 ½ inches of skin and inject the needle into the pinched skin. Slowly push the plunger to administer vitamin B12.

Front of Thigh

The thigh is a popular option to self-administer a vitamin B12 injection. Pinch a layer of skin with your thumb and index finger, which should be about an inch and a half apart from each other, in the front area of the thigh. Inject the shot into this pinched layer.

Side or Back of Upper Arm

As with the intramuscular B12 injection site on the arm, you can use the side or back of your upper arm for a subcutaneous injection. This may be easier when using the help of another person, whether that be a family member, friend, or caregiver. Pinch a thick layer of skin on the upper side of your arm and inject the needle at the appropriate angle into this pinched skin.

Frequently Asked Questions

What are the benefits of a B12 shot injection?

Vitamin B12 injections help combat B12 deficiency and can have various benefits. Benefits include increased energy levels, weight loss, increased hair growth or prevention of hair loss, and improved sleep in those with deficiencies.

Are B12 shots prescription-only?

Yes, you must see a doctor to discuss this treatment method to determine if it is the right one for you.

Do the injections hurt?

While pain tolerance varies from person to person, there is a chance you may experience some discomfort or pain, especially around the vitamin B12 injection site. The key is to relax, breathe deeply, eat healthily, and to be well-hydrated.

Are there any side effects of a vitamin B12 shot?

Generally, side effects are rare, although there are a few mild side effects that you may experience with the B12 shots, including pain, bruising or redness at the B12 injection site, mild diarrhea, itching, or swelling. While these symptoms are usually nothing to worry about, if they persist or worsen, you are advised to contact your health care professional.

Where to Find Vitamin B12 Medication for Your Injection

If you are prepared to start your journey with vitamin B12 injections and start to feel healthier and more balanced every day, then you are probably wondering how to get started and where to get the materials you need to administer a vitamin B12 shot in the appropriate B12 injection site. First and foremost, it is essential to ensure that the B12 solution you purchase is pharmaceutical grade and of the utmost quality. Before injecting the B12 medicine, please discuss your treatment with a medical professional to make sure that you are using the appropriate dosage, and that the product you are using is of the utmost quality to provide adequate and effective treatment.

When considering where to start your journey to better health through B12 shots, the best place to begin is with a trusted pharmacy. Invigor Medical offers many benefits, which include:

  • Meeting or exceeding rigorous national standards
  • Highly qualified and credentialed staff
  • The highest quality chemicals for a low cost
  • Quality sterile and non-sterile products.

If you want a high-quality, pharmaceutical-grade B12 supplement that provides diverse benefits for your health, then you should consider Invigor Medical supplement. To determine if this is the right option to improve your health and wellness, and to establish the proper dosage, you can reach out to your trusted health care professional to discuss this treatment and to determine how to obtain a prescription.

To learn more about Invigor Medical and how it can treat your possible B12 deficiency visit Invigor Medical website at https://invigormedical.com/ or find the vitamin B12 medicine at https://invigormedical.com/treatments/lifestyle/buy-b12-injections-online/

Also read – Do B12 Shots for Weight Loss Really Work?

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:

  • National Heart, Lung and Blood Institute. (n.d.). Pernicious Anemia. Retrieved from https://www.nhlbi.nih.gov/health-topics/pernicious-anemia