B12 Injection sites + How to use B12 Shots Safely

B12 Injection sites + How to use B12 Shots Safely

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B12 shots can help improve energy levels, and sleeping patterns, help with weight loss, and even improve hair growth. 

In order to get these benefits you need to be using the right type of B12 and using it correctly, which means in the right injection sites and the correct depth.

Use this guide to help determine if you are using B12 correctly and how to inject B12 correctly.

You can also find information on how to purchase high-quality B12 supplements below: 

Intramuscular vs Subcutaneous

If you’ve already decided on using B12 shots over oral or sublingual forms of B12 you are already ahead of the curve.

B12 shots are far superior to oral forms of B12 due to the fact that they have superior absorption and quickly get into your target tissues (where B12 has its action). 

While you can most certainly give yourself a B12 shot at home, there are a few things you need to know to make sure you are doing it safely and effectively.

We will go into detail on what is important and why below, but first I want to talk about the various routes of administration.

What I mean is the difference between intramuscular B12 injections and Subcutaneous B12 injections.

Intramuscular means exactly that: the injections is IN the muscle.

This should be compared to a subcutaneous injection in which the needle tip goes into the subcutaneous space rather than the needle. ​

diagram which shows how to give a subcutaneous injection at the correct depth.

The muscle is obviously deeper than your subcutaneous tissue (you can see the image above for reference). 

But the question is:

Does it matter whether your B12 shot is subcutaneous or intramuscular?

The answer is that it really depends, but in my experience, MOST patients are fine to use subcutaneous injection-sized needles. 

Most patients (provided they are lean) will be able to put a subcutaneous needle VERY close to the muscle (if not inside) depending on the site they use for the injection. 

The subcutaneous layer is thicker in people who have more body fat and therefore patients with a higher BMI may need a longer needle to adequately get into the skeletal muscle. 

With that in mind here are the injection sites you can use on your body for B12 shots: 

  • Mid-thigh (right into your quadriceps): This is the preferred site if you are self-injecting. Why? Because you have easy access to this large muscle and it’s easy to avoid major blood vessels. This location can have more fat than other areas on the body and may not be the best area if you have excess body fat. You can see the video below for a demonstration of using this area. 
  • Upper arm or shoulder area (right into your deltoid): The deltoid is the preferred area if someone you know is giving you the injection at home. There is generally less adipose tissue in this area. I don’t necessarily like this area because there is a small chance (very small) of nerve damage (1).
  • Gluteal region (into major glut muscles): This is another area that you can give an injection although one that I don’t recommend. There are large vessels and nerves in this area and this area should really only be used if there are no other options. 

You can boil it down to this:

If you are giving it to yourself consider using your thigh.

If you need someone to give it to you, consider using the deltoid/shoulder. ​

One final point before we move on to questions and answers.

In my experience, the intramuscular route is superior to subcutaneous injections.


Because your skeletal muscles are filled with mitochondria (the portion of your cell responsible for energy production in your body) and we know that B12 directly acts in these mitochondria. 

In my experience, injections in the skeletal muscles (intramuscular injections) result in a more dramatic improvement in symptoms including energy and weight loss. 

While this may not be true for EACH and EVERY person, it’s still worth considering. ​

How to give yourself a B12 shot at home: ​

Methylcobalamin vs Cyanocobalamin

If you are using B12 shots it’s also very important that you use the correct form of vitamin B12. 

Vitamin B12 (when it comes to injections) come in two flavors:

  • Cyanocobalamin <— Cheaper form of B12 that is NOT premethylated and still requires methylation once in your body
  • Methylcobalamin <— Pre methylated and active form of B12 ready to be used by the body

If you are getting B12 it’s generally best to get yours in the methylcobalamin form. 

Methylcobalamin has been shown to be superior to cyanocobalamin (2) at improving circadian rhythms in some patients who trialed both versions.

Taking cyanocobalamin if you have a methylation issue or MTHFR defect (3) in your genes can also cause issues as your body attempts to methylate the B12 before it can utilize it completely. 

This process may explain why some patients respond to methylcobalamin but NOT cyanocobalamin.

If you decide to use B12 shots make sure you know WHICH type of B12 you are getting. ​

Where to Buy B12 Shots​

If you decide to get B12 shots you need to make sure that you are getting high-quality pharmaceutical-grade methylcobalamin in a high enough dose. 

That means at each shot should be at least 5,000mcg of methylcobalamin NOT cyanocobalamin.

If you are suffering from fatigue, low energy, or weight gain B12 shots would be worth considering. 

B12 shots FAQ: 

Why B12 shots over oral forms?

Oral and sublingual B12 forms must get absorbed before they are active in your body. 

Any sort of GI problem (including hormone imbalances like thyroid problems) may limit absorption.

In fact, the absorption of B12 requires that you have adequate stomach acid (among many other factors), which means that if you are taking acid blockers for reflux you are likely reducing your absorption of B12.

It’s been my experience that many patients on oral and sublingual forms of B12 notice a dramatic improvement upon switching to B12 shots.


Because the absorption of B12 shots is superior because it doesn’t require GI absorption.

It also allows for 100% absorption right into your skeletal muscle where B12 can increase mitochondrial energy production. ​

​Who should consider B12 shots? 

It’s been reported that as many as 40% of patients in the US may have suboptimal energy levels.

Testing serum levels of B12 can be done, but serum B12 levels tend to be highly inaccurate. 


Because when it comes to nutrients and vitamins we don’t necessarily care about what is in your serum, we care about what is actually getting into your cells. 

Unfortunately testing your serum levels of B12 does NOT tell you much is actually in your cells. 

In addition, B12 must be activated in your body (through a methylation process) in order to be used correctly. 

That is why tests like methylmalonic acid (4) tend to be much more accurate than serum B12 levels. 

​It’s possible (and highly likely) that you may have NORMAL B12 levels but still have a functional deficiency of vitamin B12 in your body. 

In the most basic sense, it means that you have enough B12 floating around in your body, but you aren’t activating the B12 to be used.

By taking B12 shots you can bypass this process and directly activate the B12. ​

What are the benefits of B12 shots? 

Because B12 is present in almost every cell in your body, the benefits from B12 tend to be far-reaching.

I’ve written about the benefits of B12 shots here, but I will quickly go over the most common benefits that I see in my patients: ​

  • Increases energy and reduces fatigue
  • Increases metabolism and basal metabolic rate
  • Helps with weight loss
  • Improves sleep and circadian rhythm
  • Increases mood and concentration
  • Boost in immune function
  • Increases hair growth

The benefits depend on the person and what symptoms they have prior to taking the B12 shot. 

Will B12 shots help with weight loss? ​

Yes, B12 shots can help with weight loss by improving your metabolic rate (metabolism) and by increasing energy levels. 

The combination of increased energy and increased metabolism to the majority of the heavy lifting when it comes to weight loss. 

It’s important to note that taking B12 by itself and hoping for weight loss is NOT the best way to use B12.

Instead, you should use a combination of lifestyle changes, dietary changes, and exercise changes in conjunction with your B12. 

You can also combine B12 with other lipotropic components to further boost fat loss.

Lipotropics include nutrients like methionine, inositol, and choline. 

Back to you:

​B12 can be safely used to increase energy and help with weight loss. 

It’s important that you understand the right TYPE of B12 to use and where/how to inject it.

If you follow these instructions you will have the best results.

Now it’s your turn:

​Have you tried B12 shots before?

Did they help you increase your energy?

Leave your comments below! ​

#1. http://www.consultant360.com/articles/injection-induced-axillary-nerve-injury-after-drive-through-flu-shot

#2. https://www.ncbi.nlm.nih.gov/pubmed/8914118

#3. https://www.ncbi.nlm.nih.gov/gene/4524

#4. https://www.ncbi.nlm.nih.gov/pubmed/26807790

the safest and best way to use b12 injections

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About Dr. Westin Childs

Hey! I'm Westin Childs D.O. (former Osteopathic Physician). I don't practice medicine anymore and instead specialize in helping people like YOU who have thyroid problems, hormone imbalances, and weight loss resistance. I love to write and share what I've learned over the years. I also happen to formulate the best supplements on the market (well, at least in my opinion!) and I'm proud to say that over 80,000+ people have used them over the last 7 years. You can read more about my own personal health journey and why I am so passionate about what I do.

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