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B12 Shots For Weight Loss: Is There Proof They Work? 

6 min read
three bottles with liquid vitamin B12, a syringe with vitamin B12, B12 Shots For Weight Loss
Melissa Mitri post Reviewer Melissa Mitri post Reviewer
Verified by Melissa Mitri
MS, Registered Dietitian, Former President of CT Academy of Nutrition & Dietetics

Table of Contents

Have you heard the hype about vitamin B12 shots for increasing metabolism and losing weight? 

Vitamin B12 weight loss shots have been promoted by celebrities and influencers as a miracle solution that can make you lose weight and improve overall health. However, can B12 shots make you lose weight or speed up your metabolism? In this article, we will cover this and more.

What Are B12 Shots?

Vitamin B12, also known as cobalamin, is a water-soluble B vitamin that has many functions in the body. 

According to the National Institutes of Health (NIH), vitamin B12 supports a healthy central nervous system, red blood cell formation, and the synthesis of genetic material like DNA [1]

B12 shots is basically vitamin B12 injection that is supposed to be injected into the muscle.

Vitamin B12 is naturally present in animal products, such as meats, milk, and other dairy, poultry, fish, and eggs. Therefore, those who are vegetarian or vegan are more likely to be deficient in vitamin B12. However, it is also fortified into breakfast cereals, nutritional yeast, and more. 

So, what about vitamin B12 weight loss shots? Let’s talk about them now.

Do B-12 Shots Have a Weight Loss Effect?

Popular faces in the media proclaim the weight loss and metabolism-boosting benefits of vitamin B12 shots. 

However, there is little evidence to support B12 shots’ weight loss effects. There is minimal research on vitamin B12 levels and fat metabolism [2]

Therefore researchers recommend more studies are needed on how B12 may affect weight.

While many suggest that a deficiency in vitamin B12 can cause weight gain, the opposite is actually true. According to the NIH, a symptom of vitamin B12 deficiency is weight loss [1]

Additionally, there is no indication that a person with normal vitamin B12 levels would benefit from vitamin B12 shots. 

While the NIH does not specify a tolerable upper intake level for vitamin B12, a study published in the JAMA Network Open found that high intakes of vitamin B12, such as from daily supplementation of 25 micrograms or higher, increased the risk of bone fracture [3] [4].

Therefore, it may not be safe to get vitamin B12 shots if you don’t have a diagnosed deficiency. 

Lipotropic B-12 Injections For Weight Loss

Conversely, a lipotropic B12 injection is a specific type of injection that is meant to aid in weight loss. 

They are injected into fatty tissue in the body and often contain phentermine as well as vitamin B12. According to the Rhode Island Medical Journal, phentermine is an FDA-approved diet aid that can be obtained by prescription only. 

According to the journal Obesity (Silver Spring), phentermine has been deemed safe and effective for weight loss, but adverse side effects are still possible [5].

However, high-quality research needs to be done to determine the impact of vitamin B12 itself on weight loss.

Therefore, make sure you speak with your physician if you are considering lipotropic B12 injections. 

So, Are B-12 Shots Effective for Weight Loss?

Overall, there is not enough sufficient and high-quality evidence to support vitamin B12 shots for weight loss.

In fact, there is no indication to use vitamin B12 shots at all when you are not currently deficient in vitamin B12. 

Therefore, vitamin B12 shots are not considered effective for weight loss or weight maintenance. 

Additionally, if you are struggling to lose weight, speaking with a registered dietitian nutritionist can provide you with helpful nutritional information that is individualized to your lifestyle, preferences, medical conditions, socioeconomic factors, culture, and more. 

Also, a convenient all-in-one weight loss app can provide accountability and support you in achieving your weight loss goals. 

Proven Benefits & Side Effects of B-12 Shots

Now that we have established that vitamin B12 shots have not been shown to be effective in weight loss, let’s discuss some of the research behind the proven benefits (and side effects) of vitamin B12 shots. 

When You Can Benefit From B-12 Shots

There are specific cases in which you may benefit from vitamin B12 shots. These include vitamin B12 deficiency and malabsorption that is caused by the following medical conditions, according to the NIH [1]

  • Pernicious anemia
  • Tropical sprue
  • Pancreatic insufficiency
  • Surgery in the gastrointestinal tract
  • Certain medications
  • Deficiency in the diet

Side effects of B-12 injections

Also, according to the NIH, vitamin B-12 injections have some potential side effects, including [1]:

  • Diarrhea
  • Itching
  • Swelling
  • Risk of allergic reaction and anaphylaxis

Can Vitamins Aid in Weight Loss?

While many dietary supplement brands claim to boost metabolism, suppress appetite, or promote weight loss, research is lacking on these claims. It is best to get your nutrients from whole foods and stick with a healthy and balanced diet for weight loss.

Additionally, dietary supplements in the United States are not regulated the same way as food products are. According to the United States Food and Drug Administration (FDA), dietary supplements are not monitored for safety or efficacy before hitting the market [6]

Instead, they are just monitored by the FDA for adverse effects reported after the supplement is already available for purchase. 

Final Words / Wrapping Up

Let’s summarize some key takeaways from the article.

  • Vitamin B12 is a water-soluble vitamin that supports brain and nervous system health, helps make DNA, and more. 
  • Vitamin B12 is found in animal products, including eggs, dairy, meat, poultry, and fish. It is also fortified in nutritional yeast products and some breakfast cereals. 
  • There is a lack of research on the effects of vitamin B12 on fat metabolism and no indications that vitamin B12 shots or oral supplementation may promote weight loss.
  • Lipotropic B12 shots may promote weight loss, but may have adverse health effects. 
  • It is not recommended to take vitamin B12 if you are not diagnosed with vitamin B12 deficiency. 
  • Vitamin B12 shots may be beneficial for those who are vitamin B12 deficient due to pernicious anemia, dietary deficiency (often from vegan or vegetarian diets), gastrointestinal surgery, and more. 
  • Make sure to speak with a physician about vitamin B12 shots (including lipotropic weight loss shots). 
Disclaimer This article is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional advice or help and should not be relied on to make decisions of any kind. Any action you take upon the information presented in this article is strictly at your own risk and responsibility!

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