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Do B12 Shots For Weight Loss Really Work?
Weight Loss

Do B12 Shots For Weight Loss Really Work?

B12 injections for weight loss have been gaining in popularity. Several celebrities swear by their benefits, and more and more people are becoming interested in B12 shots for weight loss.

For people who are deficient in vitamin B12, it’s undeniable that B12 injections can have many benefits, from improved energy to better brain function. But does B12 really work for weight loss? Why are so many people now looking to this vitamin to help them reach and maintain a healthy weight? To answer these questions, we first need to look at how B12 functions in the body.

Vitamin B12 – What It is, And Where To Get It

Vitamin B12 is a water-soluble vitamin that is naturally present in animal-based food products, fortified processed foods, dietary supplements, and prescribed medication. Vitamin B12, also known as cobalamin, is involved in the metabolism of all cells within the human body. What does this mean? It means that, without the proper consumption and absorption of vitamin B12, the human body cannot properly metabolize fats and carbohydrates.

But metabolism is not vitamin B12’s only role, it is involved in a huge variety of different functions in the body, including:

  • Red blood cell production
  • Synthesis of myelin, which is needed for nerve function
  • Metabolism of fatty acids
  • Conversion of dietary carbohydrates into energy that cells can use
  • DNA and protein synthesis
  • DNA methylation (the process by which certain genes are turned on or off)

Because B12 is involved in DNA methylation, this gives it a role in gene expression, which means regulating which genes are active in the body. Although your genes themselves can’t be changed, research has increasingly shown that the body changes which genes are active and which are not. Without enough B12, this pattern of gene activation may be abnormal, which can lead to undesired consequences for various body functions. This includes the way fat is stored in the body.

B12 is also important in converting food (especially carbs) to energy that cells can use. Without B12, you may find yourself low on energy, making it difficult to exercise and stay active. It may also lead to food cravings as your body seeks to gain more energy. By helping to keep your energy levels high and allowing your body to efficiently extract energy from your food, B12 supports your overall metabolism.

Studies On B12 And Weight Loss

Studies in mice have strongly suggested an important role for vitamin B12 in lipid metabolism. In one study, mice with severe vitamin B12 deficiency became obese. They also developed problems like high cholesterol. In another study, researchers fed rats a high-fat diet, which normally causes them to gain significant amounts of weight. Giving these rats supplements of B vitamins significantly reduced their weight gain on this diet. The rats who received the vitamins also had higher levels of certain enzymes that are related to fat metabolism, suggesting that the vitamins improve the body’s ability to synthesize these enzymes.

There is also mounting evidence that B12 plays an important role in fat deposition and metabolism in humans. So while scientists can’t deliberately deprive people of B12 just to see what happens, they can study whether low B12 levels are linked with other health problems.

Several large research studies have found an association between obesity and low vitamin B12 levels. Even in children, low B12 has been associated with increased body weight. Other conditions related to fat metabolism within the body, such as heart disease, are also linked with low B12. This strongly suggests that addressing low B12 levels is important in helping people to reach and maintain a healthy weight. More research is still needed to clarify the importance of vitamin B12 for weight loss and metabolism, but the evidence that we have indicates that it plays a very important role.

Many people are able to get enough B12 through food. However, people who follow a plant-based diet may not get enough B12 since it’s primarily found in animal foods. Also, the body doesn’t absorb B12 well enough to maintain healthy levels in many people, even if they consume enough of it. This helps to explain why deficiency is relatively common. About 6% of people under 60 are deficient in B12, which rises to around 20% in the over age 60 population.

B12 Amino Acid Injections For Weight Loss

Vitamin B12 is not the only vitamin that’s important in metabolism. Other B vitamins, including vitamin B9 (folate) and vitamin B3 (niacin), are also known to play very important roles in the body’s energy use.

This is why vitamin B12 injections for weight loss often don’t contain vitamin B12 alone. Rather, they may contain several other nutrients that are also important in metabolism, including:

  • Other B vitamins (known collectively as the B-complex), which are involved in energy production throughout the body
  • Methionine, an amino acid that is important in the synthesis of enzymes and other proteins and supports the liver in fat processing
  • Choline, which is important in generating energy within cells and helps in breaking down fat for use as an energy source
  • Inositol, a naturally occurring sugar that plays a role in metabolism, energy storage, and energy consumption, and which has been shown to accelerate weight loss while helping to preserve muscle mass
  • L-carnitine, which is derived from two different amino acids, and is important in the process of generating energy from fatty acids within a cell

Collectively, these are known as lipotropic nutrients. They work together to support a healthy metabolism and fat processing within the body. Lipotropic injections containing these nutrients are commonly given twice a week to help with weight loss. However, the frequency can vary depending on an individual’s specific needs and what is prescribed.

It’s certainly also possible to have injections of just vitamin B12 on its own, but this would be more commonly used for people who have symptoms specifically related to B12 deficiency. For weight loss, it’s often preferable to include multiple nutrients that all support the body in processing fat and maintaining a healthy metabolism.

It’s important to note that lipotropic injections are not a “quick fix” weight loss solution. Rather, the vitamins and nutrients in the injections help support your metabolism, making it easier for you to lose weight and maintain a healthy weight. Many people who want to lose weight find that their bodies just won’t let go of the excess pounds, no matter how much they exercise and try to eat well. Lipotropic nutrients support a healthy metabolism, which helps you to reach and maintain your goal weight.

How To Select The Right B12 Shots For Weight Loss

There are several options for weight loss injections, and it’s hard to know which one is the best. Fortunately, you don’t have to make a choice alone. At Invigor Medical, all of our patients have a consultation with a qualified medical professional. During this assessment, you’ll be able to discuss your concerns and get personalized advice about what would likely work best for you, whether that’s lipotropic injections or another option.

In addition to injections, lipotropic nutrients are also available in supplement form. Some people may get a greater benefit from injections because this bypasses the process of absorption of the nutrients in the digestive system, which may be impaired in some cases. Others may get good results from oral supplementation. After learning more about your medical history and the concerns that you’re having, your doctor can advise you about which would be preferable in your case.

People who haven’t given themselves an injection before might be a little hesitant about the idea, but it’s actually very easy and safe to do injections yourself at home. Our patients often report that the convenience of being able to do injections themselves, rather than having to make it to appointments at a clinic, makes their treatment much easier.


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.


Vitamin B12: Fact Sheet for Professionals. National Institutes of Health.

Low Vitamin B12 and Lipid Metabolism: Evidence from Pre-Clinical and Clinical Studies.

B Vitamins Can Reduce Body Weight Gain by Increasing Metabolism-related Enzyme Activities in Rats Fed on a High-Fat Diet.

Inverse Association Between Serum Vitamin B12 Concentration and Obesity Among Adults in the United States.

Effect of Choline Supplementation on Rapid Weight Loss and Biochemical Variables Among Female Taekwondo and Judo Athletes.

Effects of three treatment modalities (diet, myoinositol or myoinositol associated with D-chiro-inositol) on clinical and body composition outcomes in women with polycystic ovary syndrome. htps://

Association of vitamin B12 with obesity, overweight, insulin resistance and metabolic syndrome, and body fat composition; primary care-based study.

Negative correlation among vitamin B12 levels, obesity severity and metabolic syndrome in obese children: A case control study.

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Written by Invigor Team

Published: Sep 7, 2020


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